Newbie Question: Dual Dellorto DHLA 45's for B23ft?

[Captain Bondo]

Ok, I know I will take heat for this, but does anyone have any thoughts on this system? They are apparently sealed for 30psi so you just make up a manifold and go blow thru with an FPR. There were OEM on some Lotus Esprit turbos

I reckon for the price of an EMS, I could buy these and a wideband O2 to keep connected permanently and still walk awya with money for a couple trips to wendy's...
I think I'd rather sacrifice a little control overall to be able to have continuous feedback and just tweak jets. (I love tweaking crap). :P

I'm wondering if anyone knows the best way to go about getting them- should I calculate all of the choke sizes, etc and build them myself? Any North American sources?

Not saying I'm going to reject ems, but it's just a thought. I'd bolt 'em up and get familiar with them on my current motor. Could be cool...

[Volvord]

I have had extensive experience with Weber DCOE and Dellorto carbs but never in a turbocharges application. These are wonderful and extremely tune-able carbs, but also very expensive!!!

Although I personally love carbs I would suggest that EFI would be the preference in any boost applications, but... I would be happy to provide what assistance I can if you decide to use the Dellorto's

[GhoSSt]

I'll always vote for EFI.

If carbs were so great we'd still see them on production performance cars from Jaguar, Ferarri, etc..

[Captain Bondo]

Ok, let's try to stay away from which is better, as I know efi will be "better", but will I notice the extra $1500? I'm not so sure...
Having a wideband and being able to tweak it with a screwdriver whenever I want is inviting, rather than hauling a laptop around, having to go to a dyno session to get the mixtures checked on a constant basis.

Especially with a MAP sensed ems, I don't think it is as "set and forget" as we think. As soon as you re-time the f'ing cam it needs a remap becuase the VE has changed with respect to rpm.

If the car in question was OEM, or if it had unlimited access to dyno time, so it could be continuously tweaked to be perfect every time I change something, or if it was set the thing up and then "DON"T TOUCH ANYTHING!!!" of course EFI would be better. But I want to mod my car, not mod it and then haul out my laptop and remap it every time.

So unless you have it dialed in every time you change something, I'm wondering how superior it will be to a carb setup you can change completely on the fly and have real mixture feedback with?

See what I am driving at? Everyone against it raises comments about ferrari, Jaguar, roadrace champoinships, etc.

But the reality is this ain't a farrari and I ain't a race team. I just want something i can drive and fiddle with easily.

[Volvord]

Your right Kenny, let's not start with a carb / EFI debate, both have advantages and drawbacks.

Don't be fooled that tuning and setting up these carbs is as simple as turning a screw, it is not. Everything is adjustable on these carbs, from venturie size, emulsion tubes, air and fuel jets, choke size, and the list goes on, so a selection of all these parts is needed to tune them, this is both costly and finding these parts in North America can be a challenge...

For simple, easy and fast tuning an EFI system is much simpler.

[945ti]

Before I got into volvos so much I was looking for a VW. A fellow had one, and he also had a custom rocco' that had a turbo and dellortos on it. I asked him about it. Here is what he told me:
I can't remember the model, but there were two carbs, both 45mm
They had no choke at all, his explanation was that it was mostly a track, weekend warrior, so cold starts weren't the issue it was all about warm smooth running adn less restriction adn complication.
He was running out of fuel at around the 400HP mark!
I am no sure what engine was in there as I was more interested in what he did to manage it and get airflow to it.
IF I were going to turbo a B20 or do something extensively custom a carb might be the most economical alternative.
I kinda like the idea, but what of the FMU and rrfpr? FMU is not an EMS, but a good FMU is similar in cost to a carb. I read an article suggesting that even the very primitive motronic that used the flapper door AMM were still more accurate than a carb. However the FMU is still working with the stock LH jet which you are trying to get away from? Dellortos are very nice, as are some webers, but they are pretty expensive, and it seems like you can still be in a similar price bracket with an FMU with more accuracy/flexability, especially when calculating fuel needs for lower RPM power. Have you priorities changes? Before you were saying that teh bottom end was the less significant side of power production, and that boost producttion/management and EMS were the most significant things to worry about, what revelation/logic is making you turn against the FMU/EMS and build up your B23?

[oppositelock]

Personally, I would never use carburettors on a turbocharged engine. I do, however, prefer them on a normally aspirated engine.

A programmable control system like Electromotive or Autronic, etc. is the way to go if you want to do a lot of tuning with a turbo. Sure, carbs are tunable but not as tunable as a programmable ECU. To get the optimum efficiency and driveability, and reliability you need to go with an integrated fuel injection/ ignition system. You need to be able to control the fuel, ignition, boost, etc. in a coordinated way to get the best results and to not melt down your engine. It's much easier to do this with fuel injection than to try to make everything work together separately with carbs.

But if you like doing things the hard way....


Just my opinion.

-Dave Clark

[Hank Scorpio]

Im with Dave. Carb's are great on n/a motors.

Kenny, why reject MS? I just finished building mine (except for the wiring harness) and its a piece of cake. I mean, true it doesn't have some of AEM's features, but really its pretty simple and cheap. You could build MS and have enough money left over for a years worth the wendy's

well

maybe for the skinny folk ;)

Ok, speaking of which Im off to eat and get a part from radio shack!

Doug

PS, one thing to keep in mind, you can't datalog with Carbs, and everytime you want to change something, you ussualy have to tear it apart. I'd ask 740TIC about his carb/holset set up, he wasn't to fond of it.

[Dan242tic]

Its been a long time since I've read about carbed turbo motors, but I seem to recall that on a blow through system it was difficult to maintain mixture at high boost. If you are contemplating big boost , you may find it leaning out too much. If you size the jets for high boost, then you may have trouble at low boost. If you are only running moderate boost then you are ok. Having a wideband O2 will let you moniter things and hopefully not meltdown. I wonder how good the seals are for throttle linkage etc. It would seem that if they can hold 30 psi that they would add a lot of resistance to throttle plate movement. Bottom line: i would think for up to 10 psi- go for it, If you want to run over that ( and I'm sure you do) I think you'd be better off spending the money on a EMS. If money is the object go megasquirt. I would like to build a carbed b23 by the way, back in the eighties they were getting close to 200 hp on dell ortos and other mods on a b21. Anyway I'm not real up on this anymore. If Lotus did it on the turbo's and it worked then I guess it will work on your car, just remember what you will be giving up with carbs (cold running, power band, fuel economy, flexibility etc). Dan242tic

[Bishop]

Using those style of carbs with a turbo will work, but getting them sorted out will take forever, most people who go carbs and turbos just wind up running super rich all the time, safer for the engine but bad if you ever hope to get decent fuel consumption.
The problem with carbs and turbos now is that because no one is doing it anymore, it's getting harder and more expensive to do.


If you really think EFI is that hard, or that expensive, I think you need to do a little more research.
A lot of the aftermarket units now have hand held controlers, and prices do compare with carb setups, and with many of the hand held units you can tune on road, without the need to go to a dyno, and some even have closed loop control so once you get it close to right you just switch modes and they fine tune themselves.
Sure it won't be as well setup as on a dyno, but then neither will be the carb setup.
And these days most guys with hot carb setups are getting them done on a dyno anyway.
Try doing an overseas search for EFI systems, there are units made in New Zealand and here in Australia that are very good and very affordable.



Sorry, I know this was not suposed to be a Carb vs EFI thing, but I just can't get over the concept of someone considering Carbs in this day and age.
:(

[Bishop]

Oh and I would not go carbs on a N/A motor either these days, have you guys seen how cheap you can get side draft style EFI throttle bodies for now???

Imagine some nice "50mm" units hanging off the side of a serious B23, complete with injectors of your choice.

[SRK]

Never trust any technology a Lotus displayed.....

The problems with a blow through are legendary, not the least of which is maintaining fuel flow into the float chamber under boost and mixture ratios during boost.

The single biggest advantage of a draw through system is the temperature drop resulting from the mixture formation in the venturi. Adding that BEFORE the compressor is a big advantage, and nearly equates to an intercooler, especially if the the mixture goes slightly rich at full throttle. If I was going to use a carb on a turbo, it would be draw through. Keeping the inlet tract short is more important on the draw through system. A manifold backfire on such a system can be "catastrophic" to say the least.

[Hank Scorpio]

hahah speaking of Lotus', the guy Im borrowing the MS stim from converted both his lotus to EFI using MS.

Hmmmmm ;)

Keep this in mind. Changing jets is not nearly as easy as changing via keyboard. Been there, done that EMS is really spoiling

[Oskari]

How many of you have had carbs on a turbo engine?

[Mika]

I wouldn´t use carbs on a turbo engine either. You´ll be better off with pressurized carbs which are built for turbo use :roll:.. The reason you don´t see Ferrari´s or any other car with carbs anymore isn´t about them being so bad, but because of emission laws that pretty much removed carbs from new cars in the early 90´s. By the way, there´s a guy here who has 250 hp engine with a single Strömberg 175 carb (these came with volvo r-sport turbo kits). That´s better than k-jet already... pushing the limits of this very old carb, but still pretty impressive.
Well, time to hit the garage, I´ll post some info about how the dellortos work when I get the car on the road.

[boosted12a]

aaaaaaaah, this is what i love, carbs and turbos! blow thru webbers are the ****!!! hands down best power for the money! ok, as far as sizing. just go with a slightly larger choke/carb than would be used in n/a form. the jetting isnt that complicated, nothing out of the ordinary. the important part is float hight and fuel dilivery system. 1. you have to have carbs with the new style "plastic" floats cause the older brass ones will be crushed from the fuel pressure. the easyes way around that is buying "new" carbs wich will run around 400$ each depending on the size. 2. you have to run an efi fuel pump, your base pressure will be a bit higher than normal, around 7-9 psi with no vaccume on the regulator. oh, you need a regulator that is vaccume/boost dependant with a 1to1 increase on the boost side. malory makes one that is perfect for the app and its only like 88$ from jegs.
the only major(not realy) drawl back is the slight bit of bog at the 4in vac-2 psi boost range wich can be worked out with a lot of tuning but its a pretty simple set up to get running and halling ass. the only problems i ever in countered were sealing of the carb bonnet to the carb itself, ida/idf carbs are the best for turboing because they wont leak fuel at the bonnet connection. for some reason, the webers seem to produce more power than efi, mabe due to the short intake tract. for shear simplicity tho, drawl thru is fun, and realy fn cheap to assemble. you can use any carb. say a 600 cfm holley with vaccume secondarys? all my experience with this stuff has been with rotarys but its still the same. id be running the blowthru on my car now except for the slight fire i had(oops) thats how i found out you need the plastic floats....id hate to suggest this guy, but thares a shop in cali called rotory shack and the owner knows alot about blow thru carbs. dont buy any thing from him, but he knows a bit. he made 1.1 liters run in the 9 sec range with a 350 cfm blow thru carb...
i say go for it, its frustrating, but its do able. good luck

[Captain Bondo]

Hmm.. I probably should not have started this debate on a friday afternoon...
I'll try to catch up here...

Volvord I hear you on the different sizing issues, but a lot of that can be calculated (choke and emsulifier tubes sizes, etc) in advance when building the setup provided you know to some degree how your engine is set up. I agree it's all greta and easy to type in value, but re-doing the whole map after a cam timing change?
A carb would act more like a AMM based efi, where fueling is actually based on airflow. It might need a small re-curve but that is pretty minor.

I think what i'm saying is you can have the most accurate gun in the world, but if it has no scope or sights on it, what's the point?




_________________
Volvord 784VC
http://www.telusplanet.net/public/gilesij/Volvord/

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945ti
"I read an article suggesting that even the very primitive motronic that used the flapper door AMM were still more accurate than a carb."

Well, that is a FACTORY tuned setup, of course it is. If you think you still have all of that accuracy whenh you start tuning via fuel pressure, and such, especuially without a wideband, you are absolutely kidding yourself.

"However the FMU is still working with the stock LH jet which you are trying to get away from?"

Ya, it's working right up to my 6000rpm redline. :roll: Also that is supplying aboyut 300hp worth of fuel at best 400hp would be a whole other ball game.

"Dellortos are very nice, as are some webers, but they are pretty expensive, and it seems like you can still be in a similar price bracket with an FMU with more accuracy/flexability, especially when calculating fuel needs for lower RPM power. Have you priorities changes?"

No chance it is more accurate. If is completely brainless to any sort of fuel curve. it just dumps fuel with boost, you might as well run a pressurized carb. At least then you could add fuel to 400hp and avoid the rediculous redline. And thwe whole "lower rpm power" is a joke. It's a low compression 2.3. I don't expect torque at 2k.

"Before you were saying that teh bottom end was the less significant side of power production, and that boost producttion/management and EMS were the most significant things to worry about, what revelation/logic is making you turn against the FMU/EMS and build up your B23?"


ALmost everyone is completely missing the point. my revelation is that buying an EMS is paying a ton of money for something that is only as accurate as the test equipment it is connected to. EMS is awesome, but i'm questioning how realistic it is to be able to get the most out of it without paying HUGE money.



oppositelock
"You need to be able to control the fuel, ignition, boost, etc. in a coordinated way to get the best results and to not melt down your engine. It's much easier to do this with fuel injection than to try to make everything work together separately with carbs."

This ai definitely agree with. The draw of EMS is the integration of it all- which is what makes my shy away from Megasquirt.

"But if you like doing things the hard way...."

Well, if the hard way will work with some effort and is several thousand dollars cheaper, it's something I have to weigh.



My man Doug,

"Kenny, why reject MS?"

The whole issue of that it cannot see or control the ignition turns me off- but then neither can carbs...
If the Megajolt integrates well when it comes out MS would move up the list a long ways. The price does make it hard to beat though so it's definitely still a consideration.


I just finished building mine (except for the wiring harness) and its a piece of cake. I mean, true it doesn't have some of AEM's features, but really its pretty simple and cheap. You could build MS and have enough money left over for a years worth the wendy's

"PS, one thing to keep in mind, you can't datalog with Carbs"

You certainly can, that is where the wideband O2 would come in. ;)

"ask 740TIC about his carb/holset set up, he wasn't to fond of it."

No but he also has 7:1 compression and a group a head which would make it a dog down low with most and fuel system imo.
Another thing to consider is he's probably making the most power of any redblock engine on here. ;)

Dan,
"just remember what you will be giving up with carbs (cold running, power band, fuel economy, flexibility etc). Dan242tic"

Exactly. All tradeoffs, and that is exactly what I wanted to discuss. Thanks for the input.

"If you really think EFI is that hard, or that expensive, I think you need to do a little more research.
A lot of the aftermarket units now have hand held controlers, and prices do compare with carb setups, and with many of the hand held units you can tune on road, without the need to go to a dyno"

LOL. I think you need to do a little more research. Not dyno tuning an EMS is a huge waste of an EMS, period except weith maybe the Megasquirt of if you have a wideband O2.



"Sure it won't be as well setup as on a dyno, but then neither will be the carb setup."

Carb setup will still be a lot cheaper at that point.

"And these days most guys with hot carb setups are getting them done on a dyno anyway."

Certainly to set things up, or without a wideband.



Oskari/740 Tic,

"How many of you have had carbs on a turbo engine?"

Not many. ANy thoughts?


Mika240

"I wouldn´t use carbs on a turbo engine either. You´ll be better off with pressurized carbs which are built for turbo use."

Hmm.. so wouldn't the dellortos be designed for turbo use?
The idea here would be that they are built to hold boost pressure without having to be sealed off, and the fuel pressure is increased with boost like a fuel injected car for enrichment

"Well, time to hit the garage, I´ll post some info about how the dellortos work when I get the car on the road."

You'rew running them? Please do post back then! :)


Boosted12a,

"aaaaaaaah, this is what i love, carbs and turbos! blow thru webbers are the ****!!!"

Ya, sound slike the Dellortos are a good way of avoiding the sealing/float crush issues with the webbers.

"i say go for it, its frustrating, but its do able. good luck"

Definitely sounds consistent with my project. LOL

[Bishop]

"Not dyno tuning an EMS is a huge waste of an EMS"

I've seen, and been in some seriously quick aftermarket EFI cars that have never seen a dyno, and all of them still ran better than anything with a carb.
One of those cars was a guy who switched from a hot twin sidedraft carb setup to aftermarket EFI, the sidedraft setup had been tuned by pros, the EFI setup was done by sourcing the EFI manifold and injectors off a Jap import wreck, he used a fuel only EFI computer with a hand controler and tuned the system all on the road using an basic O2 sensor setup.
The car made more power, idled smoother, and was a lot nicer to drive in general, and the cost was very close to what he had spent on putting on the twin sidedrafts in the first place.


Oh if you do go with carbs though I'd go with one of the single carb units designed for turbo use, either blow through or draw through, because that's the only way you will truely manage to save some money and have something that is fairly east to tune.
:)

I did almost own an aftermarket drawthrough style turbocharged gemini 1.6 once, but I hated the way it drove and chewed through the gas.

[Captain Bondo]

Cool info Bishop.

So he just used a narrow band O2?
That is my hangup, that it seems the ems could only be as accurate as the 02 sensor being used to tune it, and we all know how accurate narrowband O2's are. :roll: ;)

Megasquirt really does shoot the carb option down pretty quickly really, since you are stuck with "multiple" engine control systems that are essentially "blind" to each other.
I guess I should think about doing an MS, and then just hoping Megajolt will be a winner.
It is true that I made a decent amount of power with my existing setup,
but in my short experience with it I think there would be a lot to gain with even just a 1000rpm higher redline.

[Oskari]

The Dellortos are good low budget solution, there is no big diffrence between ems and carbs on wot, i mean, your engine doesn´t know from where the fuel comes.

[Bishop]

Cool info Bishop.
So he just used a narrow band O2?
That is my hangup, that it seems the ems could only be as accurate as the 02 sensor being used to tune it, and we all know how accurate narrowband O2's are. :roll: ;)

Well, I can't remember exactaly but his unit was either calbrated off a shop unit or was a pre calabrated unit bought off a shop.
One of the things that did make the who thing easier is that he EFI comp he bought came with semi pre set maps to suit diffrent uses, it took away a lot of the early guess work and allowed him to basicly plug it in and get a smooth idle in just a few mins.

[Bishop]

there is no big diffrence between ems and carbs on wot

I so can't let that one go...

Not true, with EFI you have injectors squirting fuel directly into the correct chamber at a mist level that a carb could only ever dream of, you get a better burn and more power, there are very few engines where you won't get better power with multi point EFI.

[Anonymous]

But does quench/squish make that issue more or less redundant?

[towerymt]

I would think MS would be cheaper than the carb setup, easier to setup (especially for you, as I believe you have some knowledge of those circuit boards :wink: ), and would still allow you the tuning and tweaking fun that you're after. And if you don't like it or upgrade later, unloading the MS would be easy.

I have a hard time seeing how carbs would be worth trying.

[Oskari]

[quote:8046a55584="Oskari/740 Tic"]there is no big diffrence between ems and carbs on wot

I so can't let that one go...

Not true, with EFI you have injectors squirting fuel directly into the correct chamber at a mist level that a carb could only ever dream of, you get a better burn and more power, there are very few engines where you won't get better power with multi point EFI.[/quote:8046a55584]

I didn´t say there is no difrrence at all, did i....

[Oskari]

I would think MS would be cheaper than the carb setup, easier to setup (especially for you, as I believe you have some knowledge of those circuit boards :wink: ), and would still allow you the tuning and tweaking fun that you're after. And if you don't like it or upgrade later, unloading the MS would be easy.

I have a hard time seeing how carbs would be worth trying.

If that is true, Ms would be cheaper to you, of course you should go for it..


I bought used carbs and intake manifold, they were 400€ vs about 2500€ for complete ems system.

[Anonymous]

It seems like it's getting into the "this is better, that isn't" and name calling zone again, so I'll get this in and make an exit: Kenny - do you have a pair of Dellortos or Webers laying around? An intake? Throttle linkage? An adjustable, manifold referenced fuel pressure regulator capable of setting base fuel pressure to less than 5 psi? The plumbing to hook up a turbo bonnet to a pair of carbs? The jets and tubes and chokes for tuning??? I'd lay $10 of my hard earned money saying that once you add all that stuff up, including your time and effort, you'll be spending $1000 and a hundred hours of farting around getting it all hooked up. Will it be cool once you're done? Undoubtedly. Driveable? Probably not as much as an EFI.

Do a search on Yahoo Groups for Blow Thru Turbo and JY Turbo. There are lots of guys on there with experience tuning carbs and turbos. They make 'em work, but they can be a pain.

You're talking about tuning it with a WB-O2 and calling it good. What's better about tuning a carb with a WB-O2 than tuning an EFI with WB-O2? They'll both be about as accurate as each other because the measuring tool is the limiting function. You can probably do better with carbs and a steady state dyno, 4 gas analyzer, EGT probes, etc., but you'll be spending the same money tuning it as if you were tuning an EMS that'll also control spark and boost... except that for every mixture change, you're buying parts. You said that an EMS without dyno time is a waste of EMS, but tuning an EMS with a WB-O2 will be as accurate (and easier) than tuning a set of carbs.

Remember, with the EFI you can change MAP and RPM bins and pinpoint the exact changes you want to make - with the carbs, every component overlaps something else, so it's not as simple as making one change to get it right: If you're lean from 4500 RPM and up but otherwise right on the money, you will have to decrease the air correction jet and decrease the main jet sizes to richen up the top end. Once you make those changes, you may find that from 4500 - 5000 RPM you're too rich but perfect everywhere else. Time to pull out the emulsion tubes and try again, though now you've got to throw away that whole combination you had and start with a new air correction jet and a new main jet. This is just one example of a common tuning problem - try fixing a low RPM bog with accelerator pump springs and bleeds and idle jets!

However, you do have a point in that carbs behave like airflow based EFI systems, so changing the cam, exhaust, timing, etc., won't affect the mixture nearly as much as if you were using a MAP based EMS. However, I think this is the only selling point with carbs, unless you've got the carb, manifold, linkage, etc. sitting around already.

Sorry about the length of this post...
Matt Dupuis

[dl242gt]

Carbs behave like an airflow based injection? You mean like K-jetronic
airflow based injection? That's why I'm happy with my K-jetronic injection.
If I make any changes the injection automatically compensates as long
as I'm not exceeding it's limits. So, I'm not going to exceed it's limits.
The hp I'll get with the K-jet is enough for me for the street at least
for now. Sure K-jet isn't the greatest but it is very good and easy to
work on. It's also more efficient than carbs.

Carbs are going to be more maintenence intensive but they are fun. I'm
with the folks who like them for n/a apps. Or if I had an old Corvair turbo with a suck through system. Wish you well with what you decide.

Dave 82 242ti

[volvorsport]

im away five days and kenny goes on about turboing carbs !! , ive been on about it for a while .

Its true that you need carbs which are specifically made for turbocharging since they have progression drillings and all other things nice for it .

If you went with the stromberg carb , i can get you the jet and needle that will make you run 155 hp since thats what the r sport conversion was .

you could of course have two strombergs !

Sometimes on webers you might have to put a restrictor plate at the entrance to the carb to make them fuel correctly since the cross sectional area change signals the float chamber with higher pressure from boost giving more than 1:1 fuel ratio change .

Basically theres no limit to Hp you can run , get a sincle carb manifold , cut it up a bit , fit two strombergs , get filing those needles , youll run out of transmission before the engine runs out of air .

webers usually make more power becaue they have a better manifold design , EMS is only as good as the operator who tuned it .

I think for £100 i could have my twin carbs and fuel regulator to run ?how much Hp?

think about it guys , its not like a really daily driver its a fun machine

[Captain Bondo]

"Kenny - do you have a pair of Dellortos or Webers laying around?"
An intake? Throttle linkage? An adjustable, manifold referenced fuel pressure regulator capable of setting base fuel pressure to less than 5 psi?"

No, but I also do not have a set of 600+cc injectors, high flow fuel rail, oversized or multiple throttle body system, etc... Setting up a megasquirt or ems to run on stock componenets is cheap enough, but when we're talking 400hp fuel systems I think the aspect of buying/fabbing parts is moot between the two.


"the plumbing to hook up a turbo bonnet to a pair of carbs?"

Again I can't see this being any more serious than the plumbing any intake system for a 400hp engine with ANY induction system. I am considering custom plumbing and a fabricated intake manifold a given with either setup (I hate the volvo efi intakes)- but imo a set of runners going from the head to the carbs, and then a plenum chamber after that, basically set up so the carbs are working as independent throttle bodies is much easier to fab than a manifold with efi indy-throttle bodies, injectors bosses, fuel rail system, etc.

"The jets and tubes and chokes for tuning??? I'd lay $10 of my hard earned money saying that once you add all that stuff up, including your time and effort, you'll be spending $1000 and a hundred hours of farting around getting it all hooked up. Will it be cool once you're done? Undoubtedly. Driveable? Probably not as much as an EFI."

Yes probably. I would forsee an equivalent efi induction system with indepentdent throttle butterflies and etc (comparing apples to apples- or trying to in the sense of you can't compare a carb system with custom manifolding and independent butterflie to a OEM efi intake and single throttle body) being at least as much farting around and at least as much expense.

"They'll both be about as accurate as each other because the measuring tool is the limiting function. You can probably do better with carbs and a steady state dyno, 4 gas analyzer, EGT probes, etc., but you'll be spending the same money tuning it as if you were tuning an EMS that'll also control spark and boost..."

Agreed, the sensors are the limiting factors. But if you want to have an EMS that controls spark and boost, it will run WAY over the $1000 you used for the carb setup. If the whole carb setup cost $1000 and reliably provided 400hp worth of fuel with some reasonable degree of accuracy, I'd definitely do it.

"You said that an EMS without dyno time is a waste of EMS, but tuning an EMS with a WB-O2 will be as accurate (and easier) than tuning a set of carbs."

Yes. probably more accurate. Still not convinced it is cost effective though, with the exception of megasquirt.

**snipped some great points on tuning**

I dunno, there is a ton of crap to buy regardless, but megasquirt is so rediculously cheap it is pretty hard to argue with.
A full ems would be awesome, but I just don't know if I can justify 2 grand just for the hardware.

But it's really hard to argue with megasquirt, I'm pretty sure a dyno tuned megasquirt setup could be done for as much or maybe even less than carbs and be more accurate.

But I think besides carbs being ariflow based, I think there is another advantage the do to the "better" induction format as far as manifolding goes that is sort-of "built in".

But when it comes down to it, MS will probably find its way into the car.
I'd love to do an AEM, and maybe I even would, but it's tough to balance where you have to pay to play, but I want to play before I'm 50 and finally have the money for the "ideal" system.

I'd rather drive a car with less than ideal parts sometimes than sit around and look at an "ideal" car that's never done. :D
But it's hard to balance becuase my stock B21ft is less than ideal and it really sucks compared to the old engine- everyone has their standard I guess.

[JohnLane]

Kenny how much dough do expect to have into your engine without your pressurized carbs? Are you aware of just how troublesome that arrangement was in the early Esprits?
All the OEM's now have injection so that they can have good drivability with good emissions and power without all the babysitting that goes along with carburators.
For the added $1500.00 just do Electromotive or something laptop programmable and know that you have just spent your money wisely.
We all know better then to think that we are going to see that A/F ratio gauge go lean for the ten seconds that it takes in the heat of battle to blow the damned thing up.
Hmmmm........Change jets........Click-Clack on a keyboard.......With programmable you will be able to see the changes as you do them im real time on the computer as your buddy drives.....Oh---A little lean at EXACTLY this point? We will add a little fuel at EXACTLY this point.......Oh...It pings at EXACTLY this point but is not lean? We will back timing off a few degrees at EXACTLY this point.....until it is perfect!!!.........Change jets........Go drive......Damn!!! Wrong way........Change jets........Oops...Too far......Damn.....Flooded the dumb thing again......Poor drivability when cold.......Carbs are for crummy old british cars. Oh....You will still have to deal with ignition with your pressurized carbs.......
OK, I'm off the soapbox now. Flame away!!
JL.

[JohnLane]

What? No flames?? This is not like you guys. You guys feeling well??
Come on now. You guys can do better then this!! :roll: JL.

[volvorsport]

you hillbilly canadian arse jockey !!

hows that ?

youre right , some crummy british cars were fitted with carbs , but since volvos were aswell , i shall retract that statement for you !

carbs can be good and if kenny has something lying about it will be cheaper , that might not mean better , if i could do it , megasquirt would be the way .

[SRK]

If my memory serves, John is American. Does that mean that your use of the term "canadian" in and of itself is supposed to be derogatory?

As for crummy English cars, at least they had the most elegant carburetor ever devised on them, the SU.

[Hank Scorpio]

John, nothing to flame you on, your EXACTLY right!

[dl242gt]

"As for crummy English cars, at least they had the most elegant carburetor ever devised on them, the SU."

Yeah, with a silly name like "Skinners Union". hehe.

Dave 82 242ti

[SRK]

Well you got your:
Mr. Skinner
Mr. Holley
Mr. Carter
Mr. Stromberg
Mr. Edelbrock
What's the difference? They all liked cars, they all made carbs.
Holley's are the next best thing to an uncontrolled fuel leak, and Mr. Carter liked plastic.

:badboy:

[Hank Scorpio]

Rochester Q-jet, best 4bbl carb hands down ;)

[volvorsport]

well , since twin 40/45s are fitted almost everything rally car here that isnt japanese or cossie , i dont think youll have the problem everybody says youll have if thats what you really want to do .

the only difference is that you are running a turbo .

Also , why do superbikes still use carbs ? and why is valentino rossis team going back to carbs after fuel injection .

would somebody like to answer that ?

And i have nothing against canadians ! . God damn yankees O:-)

[Bishop]

Also , why do superbikes still use carbs ? and why is valentino rossis team going back to carbs after fuel injection .
would somebody like to answer that ?


Weight is a factor on motorbikes, also they don't really care about bottom end control or power, cost is also a factor (on road bikes), and it's not even an issue trying to compare bike carbs to car carbs, they may both be carbs but they are in a whole diffrent league.
Bike carbs have things like electronic throttle position sensors etc, among other way out there features.

[JohnLane]

Careful how you throw those darts Tiger.
Calling me Canadian was a shot below the belt. :roll: I would be a YANK.
Yup......Them carbs are JUNK. Were the technology avaliable a wayyyy back when the Skinner's Union (Very pretty when polished up to be sure) carbs that have ensured the demise of Ohhh sooo many of the vehicles they were fitted on by our favorite means......FIRE!!!!......Those folks would have no doubt have used fuel injection.......
Why are the bike guys going back to them? 'Cuz when saving six or seven pounds makes a differance and they are not using forced induction with an engine that has a usable powerband of 1200 rpm's one can dial carbs with two moving parts (slidevalve does throttle and pull up the fuel metering needle....Maybe a floatvalve) in just dandy. Our cars with a few more operating requirements require something a little more suitable for what we are doing. Yes, Programmable injection is far and away the better answer for our turbo-toys. I gave up on thinking that babysitting Webers was cool a LONG time age. Do keep in mind that I had a pair of IDA-3's on my V-6 for a few years. Made a really cool noise, and required CONSTANT babysitting to keep them running well. This in naturally aspirated flavor. I can just imagine what it would have been like in pressurized flavor. Yuck!!
:P Bring it on guys!! Oh---You guys can do better....I have seen it myself.
JL.

[Volvord]

Many would argue both sides, even the experts can not agree. Take a look at what they say when comparing EFI to carbs http://www.carcraft.com/techarticles/849/

[SRK]

An excellent article, well worth reading. What it points out so well, reading between the lines, is that generalizing about fuel systems ( and from this we can extrapolate to most things in life ) is fraught with danger. Pitfalls abound. Dogma. Myth. Superstition. The Bermuda Triangle. Sasquatch. The Inquisition.

Run like hell from it all.

Use what you like and be happy. I would have used a Holley Projection system on my 460 Ford Cobra. But it didn't look right. It would have performed very well I am sure. It had to look right. And sound right. So the 750 Holley barely controlled fuel leak did look and sound right. And my 5.0 HO '82 GLT was perfect with the Ford EEC-IV system intact, excellent daily driver, just what I wanted. So it retained fuel injection.

So if I ever build a turbo B20 it will use a draw through system with a big honking 2 inch SU, because that's what I like. And if I get blown away by some hybrid V-6 with the devil's own induction system, it doesn't matter.