• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

15.29 @88 MPH, what's next?

D

dmann

New member
Joined
Apr 22, 2015
Location
Sacramento CA
1987 760 turbo, 3 inch cat back exhaust, bosch 044 fuel pump upgrade, new in tank pump, manual boost controller.

I was running around 13 or 14 lbs of boost on that run and it felt pretty good. I upped the boost more, like around 17 or 18 lbs and I got severe wheel spin off the line and then a flat feeling top end rush. My mph went down to 84 though I did spin all of first and second. On the higher boost setting I had very audible ping in first gear.

I'm running 91 octane fuel. My wideband shows around 10 or 11 to 1 AFR at 10PSI boost and it starts going up after 10 PSI. By 17PSI I'm at around 12 to 1 AFR.

My engine internally is stock as far as I know, as is my LH 2.2 and my ignition system. I'm running NGK 7 something plugs and the slightly lower temp thermostat. Stock air filter element but the thermostat is forced closed in the airbox and the little silencer is gone. I did the accumulator mod to the transmission.

The best run of the night was 15.29 @88 MPH in Northern California near sea level @ about 73 degrees F. This was at about 13 or 14 PSI boost.

I can't really run any more boost without risking detonation on this combination.

What's the next logical step to go faster? I don't want to pull the head off right now if I don't need to, but I guess I could if that had to be the next step.

I really was hoping to get into the 13s on this basic motor.

Dan
 
Put it on a diet, so less to strip down when you crush it.
 
dmann said:
1987 760 turbo...manual boost controller...I upped the boost...17 or 18 lbs...On the higher boost setting I had very audible ping in first gear...I can't really run any more boost without risking detonation on this combination.
Click to expand...
You should start looking for a decent 93+ shortblock. Squirter engines will blow up from too much of that 'pinging under boost' abuse, skinny rod motors like yours will do so even more quickly.

What's the next logical step to go faster? I don't want to pull the head off right now if I don't need to, but I guess I could if that had to be the next step.
Click to expand...
Pulling the head off to do what?

Megasquirt it and get full control of the fuel and spark.
I really was hoping to get into the 13s on this basic motor.
Click to expand...
It's certainly doable. Just might need a few more mods otherwise you'll be scattering the bottom end out onto the pavement.
 
You really don't need porting yet. Maybe a cam would help. Is it a manual trans or an automatic?

Bigger turbo - stock sized turbos were selected with fast spool and stock HP levels in mind.

Better intercooler - same issues as above. Great for stock amounts of HP, lightweight and limited amount of heat transfer capability for added heat from higher boost.

3" needs to go all the way to the turbo. I think a 3" DP and cat hooked to a stock exhaust would be better than a stock DP and cat hooked to a 3" system.

Some more injector flow, some higher octane fuel (somehow, I have limited experience with octane booster, and what experience I have is bad lol boom), some more control over the ignition timing under higher boost.

And some stickier tires. You don't really seem to have enough HP to be spinning through second gear.
 
JohnMc said:
You really don't need porting yet. Maybe a cam would help. Is it a manual trans or an automatic?

Bigger turbo - stock sized turbos were selected with fast spool and stock HP levels in mind.

Better intercooler - same issues as above. Great for stock amounts of HP, lightweight and limited amount of heat transfer capability for added heat from higher boost.

3" needs to go all the way to the turbo. I think a 3" DP and cat hooked to a stock exhaust would be better than a stock DP and cat hooked to a 3" system.

Some more injector flow, some higher octane fuel (somehow, I have limited experience with octane booster, and what experience I have is bad lol boom), some more control over the ignition timing under higher boost.

And some stickier tires. You don't really seem to have enough HP to be spinning through second gear.
Click to expand...

I have the aw71 automatic transmission. I'll have to find out if the bigger downpipe would be legal for me in California. Is the stock downpipe really limiting at this power level?

I have considered the cam, but I didn't know how much I would benefit from it at this level.
 
If you're having trouble off the line, pick up a set of drag radials.

I'd run 12:1 at 17psi but I understand it is getting near that iffy zone. What injectors are you running? Consider upping to 42lb/hr or equivalent units.

15.29 isn't bad. If you stopped spinning the tires I think you'd dip into the 14's.

Once you get some drag radials you can try brake boosting on the line...
 
play with the ignition timing with the boost at a lower level (~14). trap speed is off from what it probably should be at that boost level and modification level (mainly, the exhaust). at 14ish psi with 3 inch exhaust you should be trapping in the 90's. with some better fuel (maybe toss in a couple gallons of e85 if it's available), a little more timing, and more boost it should run off in the low 14's. beyond that you get into a bit of nuance and further mods. The engine from a strict capabilities standpoint, will go 12's more or less stock (+better cam). an 87 vintage one won't do it as many times as a newer engine, but meh.
 
linuxman51 said:
play with the ignition timing with the boost at a lower level (~14). trap speed is off from what it probably should be at that boost level and modification level (mainly, the exhaust). at 14ish psi with 3 inch exhaust you should be trapping in the 90's. with some better fuel (maybe toss in a couple gallons of e85 if it's available), a little more timing, and more boost it should run off in the low 14's. beyond that you get into a bit of nuance and further mods. The engine from a strict capabilities standpoint, will go 12's more or less stock (+better cam). an 87 vintage one won't do it as many times as a newer engine, but meh.
Click to expand...


I have stock injectors for 1987 as far as I know. At 13-14 PSI I didn't seem to have any traction issues. It wasn't until I raised the boost on the last run of the night that I hazed the tire.

I'd been thinking about getting a megasquirt. I've also thought about the ipd turbo cam. I dunno which is the better intermediate step at this point.

I'm not sure why my trap speed is so low. I've wondered in the past if I have bad valve springs. Sometimes it acts like it wants to hesitate or "fall over" at higher RPM. A few months ago it was really noticeable but I added the new fuel pump, higher boost, and I replaced the turbo intake hose and it's improved a good deal.

I have a stock airbox and AMM, are those very restrictive? Do valve springs in these engines have a habit of going bad?

If I do change the cam, does anyone have a favorite? I know about the IPD turbo cam, and I've heard of others, but the information on all of those other cams is a bit confused or conflicting.

My turbo does make a crap ton of noise if I build boost before the engine has warmed up good. It sounds like it has shaft play and it's vibrating. Dunno if that's what's really happening or not. Once it's warmed up it sounds fine.

I do have the typical oil residue inside the intake hoses. I cleaned out the intercooler about a week ago.

I have to pass California emissions so I need to be mindful of that with the modifications that I may make.
 
dmann said:
I have stock injectors for 1987 as far as I know. At 13-14 PSI I didn't seem to have any traction issues. It wasn't until I raised the boost on the last run of the night that I hazed the tire.
Click to expand...

not launching hard enough if it's not at least a threat to spin at 13-14 (spin != blow a tire off)

I'd been thinking about getting a megasquirt. I've also thought about the ipd turbo cam. I dunno which is the better intermediate step at this point.

I'm not sure why my trap speed is so low. I've wondered in the past if I have bad valve springs. Sometimes it acts like it wants to hesitate or "fall over" at higher RPM. A few months ago it was really noticeable but I added the new fuel pump, higher boost, and I replaced the turbo intake hose and it's improved a good deal.
Click to expand...

T cam doesn't really make it rain much above 5k, but unless it's worn out or something that isn't why your trap is only 88

I have a stock airbox and AMM, are those very restrictive? Do valve springs in these engines have a habit of going bad?
Click to expand...

amm might go bad, stock airbox isn't that bad really. springs can go lazy, be more apparent with a hotter cam.

If I do change the cam, does anyone have a favorite? I know about the IPD turbo cam, and I've heard of others, but the information on all of those other cams is a bit confused or conflicting.
Click to expand...

ipd turbo cam is a good basic bitch cam, there are certainly better cams out there that become available from time to time. If you have a better idea of where you're ultimately going you could get just about anything either made or ordered from overseas, but at the stage you're currently at, you could do a lot worse than an ipd turbo cam.

My turbo does make a crap ton of noise if I build boost before the engine has warmed up good. It sounds like it has shaft play and it's vibrating. Dunno if that's what's really happening or not. Once it's warmed up it sounds fine.
Click to expand...

that's odd. turbos don't really 'warm up', may want to pull the housing off and see if it's tagging up. If you want to stay with the garret framed stuff, I'd suggest a 60 trim compressor wheel upgrade (cheap, and awesome). If you do end up with a 60 trim and a cam, your next big limiters are going to be the intercooler and management, but you should be able to push the mph up another 10 before the management is really starting to be questionable.

I do have the typical oil residue inside the intake hoses. I cleaned out the intercooler about a week ago.

I have to pass California emissions so I need to be mindful of that with the modifications that I may make.
Click to expand...

Sure. you don't need a bunch of **** to have a really quick car, just tuning and careful parts selection.
 
THe engine is choking on hot air at high boost high rpm, really limiting your peak power.
The stock cam won't be a restriction until you free up the exhaust from that stock cat. The detonation aND power loss will continue until you upgrade the turbo. That's why more boost was slower.
After those two things you'll need more fuel, which is tricky on LH 2.2, and more cam which really needs spark control to maximize results.
 
3" dp and cat delete, keep the stock stuff for smog? Its like 6 bolts and an o2 sensor to swap...

M.
 
dmann said:
15.29 @88 MPH, what's next?
Click to expand...



IMG_0018.JPG
 
The factory cat was replaced about 2 years ago. I don't think it's a huge flow restriction, but I haven't measured back pressure.
 
I guess it's probably a good idea to test the cat, so I ordered a gauge from amazon http://amzn.com/B0002SQWVQ

Normally I'd have something laying around I could cobble together to do the test but I moved recently and all of my junk drawer stuff got tossed out...oh well :-(

I should have results of this test sometime Saturday, Sunday at the latest.

I've been thinking about ordering a megasquirt and making a breakout box type deal so that I could go back to the factory ECU and ignition if needed.

I just don't know if I have access to what I'd need to do all of the tuning. I'd be most concerned about the timing curve and what not. Is there a repository of good baseline megasquirt files for a mostly stock volvo b230ft?

If I don't scratch this itch I'll just want to buy a new/newer car that is sporty out of the box, and I'll end up with a car payment and higher insurance payment. I may as well just try to get this thing into the 13s.

Basically my buddy at work has a stock 2015 wrx...and I'd like to be able to punish him a little at the drag strip. That is really my goal at this point.

Thanks everyone for your thoughts. I am considering an IPD turbo cam, but would I be better off to do the megasquirt first? Megasquirt at my current power level doesn't gain me any power, is that correct?

I guess with megasquirt I could run e85 probably.

I'll check the ignition timing the same day I run the back pressure test and I'll report back my findings Kenny.


Dan
 
Oh yeah...I have an iDash now that I've hooked up so if anyone wants pics or info, just let me know.

I have wideband 02, RPM, and boost sensors all logging. I still have 2 more sensors to connect, fuel pressure and air temp. I want to get a second air temp and measure pre and post temp on the intercooler.

This is it: http://www.14point7.com/products/idash

Dan
 
You must log in or register to reply here.
Back
Top