Turbo Suggestions

I'm not a turbo guru by any means, but I'm learning.I want to build a new engine for the 740 I auto cross. I would assume I'm looking for around 300+ hp. Set up will be:

16v head
stock cams
RSI Pistons and h-beams
RSI 16v stainless steel exhaust header
Sheet metal intake from Nathan
Electronic Boost Controller
Aftermarket Engine and spark (undecided as of yet)

More important than max HP, I need a turbo that will spool quickly for short auto cross courses..Lower rpm the better. I don't think I'll need any more than 15-20 psi of boost

What turbo would be a good fit for this. I'm not looking for cheapest ok. I'm willing to pony up for ball bearing turbo to get quick spool if needed. So what say ye turbo gurus?

There was a Rx7 out there with a huge turbo that was useless. It was a dog (lag) until just before he had to brake, then all hell would break loose. I want to avoid that. I need boost down low.

Why not a 15G?

16/19t and be done

or if you want a bling turbo get an HRC super 16g

Hey I'm just learning these turbos. The better question why would a 15g work for what I'm needing.

15g is too small and won't support that motor- they're only good for about 200-280whp, realistically, and that's pushing it at the top end of that whp estimate. The spool will be too quick and putter out too soon. HRC 16g's are good for 300-350whp. I'm actually having one put on my car this week. For a 16vt, the 20g is actually a better match if you're looking for pure numbers, the same price, and good for 300-400whp, but Josh from Yoshifab makes a good argument that the 16g is a helluva lot more fun due to quicker spool and 350whp all day long.

Then maybe he is building more motor than he needs?

I hear from others that the 16v engines while making great peak power seem to be lacking on the lower end torque, this sounds like an ideal setup for an 8v stump puller.

Why not take a stock engine and bolt up a 90+ and 15g (OR 18T/19T) with a full exhaust (3"), upgraded intercooler and see what it does with those parts. OP might be happy making 220+whp and having something that spools super quick and make good torque.

If you really wanted to do more custom parts go with a custom exhaust manifold with an evo8 turbo, I can tell you that Fige's car feels almost n/a in the power delivery and even with the stock intake manifold makes stupid good power.

That would be my recommended route, IPD turbo cam, Custom manifold (be it J pipe off n/a manifold) or full on custom with an Evo8 turbo with an upgraded intercooler and just rock that out. LH will work but MS would help it spool and pull way harder, That setup can be done for easy $1000 and not have to deal with the engine or head ever coming off the car.

I agree that 16V is not necessary in your situation. My B230FT with a tubular manifold, Tial 38mm wastegate, and Garrett GT2871 turbo made 20psi by 3000 rpms, and was awesome to drive. At 25psi it put my car in the 11s in the 1/4 mile. Even so, it was very driveable, and was a blast to autocross. The turbo would spool so quickly, making it easy to drive while dodging cones.
Are you planning to get rid of the auto trans as well? I watched one of your latest videos, and think that a manual would be much more suited to autocrossing as well.

I have a t5z just waiting for Clutchnet to send my damn disk.

Ok...With further thought, I agree. For what I am wanting, a 16v is not needed. Especially since the 16v is better suited for high rpm HP. What I need is low end torque for auto cross. And if I can get what I'm wanting from a non-interference 8v head, all the better.

With that in mind..
RSI bottom end - rods and pistons
Mildly ported 8v head
IPD Turbo cam
tubular exhaust header
maybe garrett gt2871
Tial 38mm wastegate
Good aftermarket inter-cooler
sheet metal intake from Nathan
MS or some other management
15-20 psi boost
electronic boot controller

Does this sound like a decent set up for my needs. 250-300hp maybe with lots of low in torque. Boost coming on quick.

if you really only want 300hp tops, why drop all the cash on the bottom end and manifolds?

Margin of safety on the bottom end. I know stock can probably handle 300hp, but for how long? I have scattered my share of rods (not red blocks) on the highways already. Besides, I'd like the option of cranking the boost up more in the future if I so choose.

Stiggy Pop said:

if you really only want 300hp tops, why drop all the cash on the bottom end and manifolds?

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fair enough, definitely understand wanting the comfort and ability to go for it.

Still sounds like you are spending way more $ than needed.

I like the Jesse approach of doing all of the bolt ons first. Especially if you goal is well within the limit of stock parts as if something stupid goes wrong like a bad oring(pickup tube) or injector fails of valve drops can you really afford to rebuild a $5k engine and head when a $300 junkyard engine can make the same power.

I know of a local who did the entire built engine setup and his car has had nothing but issues because of faulty machineshops and a few bad eggs helping him. Meanwhile my stock motor is still chugging along while his project has sat because of cost to replace big $ parts. It is only of as of late going back to a stock block and other low dollar parts that let's the car run and drive now. Plan for worst case.


I was at 301whp in 2009 (5+ years) and since then I have done nothing but beat on this motor making even more power and it still to this day runs just fine. My rings might not be in the best of shape but I havent run a crankcase vac in like 7 years so. A refreshed (hone and new rings and bearings) short block will take 300whp for longer than you think.

My biggest worry since u have dumped real $ into my car has been if any of those high dollar parts fail I am pretty much going to park the car for a year or two so I can reafford it. It is the same reason i am holding back on soending $1000+ on a turbo when my current $500 7 year old turbo still works just fine. Because even if this holset fails i can get it replaced much cheaper than say a gt series turbo. I guess i am just being cheap.


Check out fige's build as his engine and trans setup sounds spot on to what you want for autox.

Thanks guys for the suggestions. Makes sense thelostartof....I was just not sure I could reach the level I was wanting without some of these parts. But sounds like its doable... Heck, I'll reassess what I want to do after I get the T5 installed, and bump my boost up to around 12. I might be just happy with that for a while.

Can someone give me a link to fige's build.

Stock engine
RSI Stage 3 cam
t3 60/63
upgraded intercooler "anything is better than stock"
nice 2.5 inch or bigger exhaust
Megasquirt
650cc injectors
E85
22psi

315whp 336wtq



Thats what I would suggest


-Sam

thelostartof said:

Then maybe he is building more motor than he needs?

I hear from others that the 16v engines while making great peak power seem to be lacking on the lower end torque, this sounds like an ideal setup for an 8v stump puller.

Why not take a stock engine and bolt up a 90+ and 15g (OR 18T/19T) with a full exhaust (3"), upgraded intercooler and see what it does with those parts. OP might be happy making 220+whp and having something that spools super quick and make good torque.

If you really wanted to do more custom parts go with a custom exhaust manifold with an evo8 turbo, I can tell you that Fige's car feels almost n/a in the power delivery and even with the stock intake manifold makes stupid good power.

That would be my recommended route, IPD turbo cam, Custom manifold (be it J pipe off n/a manifold) or full on custom with an Evo8 turbo with an upgraded intercooler and just rock that out. LH will work but MS would help it spool and pull way harder, That setup can be done for easy $1000 and not have to deal with the engine or head ever coming off the car.

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16VT's don't lack lower end torque, really. I can tell you that my barebones 16vt on generic 2.4 computers and TLAO chips with a 15g, 90+ exhaust manifold, with the B204GT intake manifold and a stock intercooler was significantly faster (ran a mid-12's trap with some speed I can't remember off the top of my head) than my current 8V with chips, injectors, aftermarket intercooler, turbo cam, 3" turbo-back exhaust, etc. My personal opinion and from my own personal experience with 16vt is that it's the way to go if you have the money to do it. The 16vt head flows way, way better, and you can easily achieve great numbers all across the board without the need for giving up the durability of a cast iron exhaust manifold, performing extensive head porting, and pushing the limits supporting mods surrounding the 8v in general.

Your built bottom end is actually exactly what I'm going to do with my next 16vt and I plan on running a very moderate 300-350whp. With a 16g you'll instantly spool and make torque all day long and not worry about anything truly catastrophic happening to your motor. There are absolutely no downsides to 16vt if you can afford the route. I personally wouldn't want to push 8v past 250whp due to the cost-benefit ratio compared to slapping on even the most basic 16vt setup and achieving the same levels of power effortlessly.

If you're already considering putting good money into a motor, 16vt has consistently proven itself to be a performer. I think you are in the right mindset to overbuild and undertune, all things considered.

Honestly, with a 90+ motor you've already got decent rods in there, just no squirters. 2.4 will do quite a lot without needing much more than chips. One of the biggest restrictions is the hot side on the TD04HL turbo's, but even so, they still do pretty well. Cams are also a HUGE thing to consider. Personal experience, the VX I had in mine was a damned stump puller and would relieve me of tread without issue by 7-8psi, pretty much on demand, but it was done by 5k. I swapped in the IPD turbo cam which winds out but it definitely is missing the low-end that the VX at 3* had.

As for the recommendation of the Garrett 2871, yeah, I gotta say, it's a badass for sure without the bottleneck of the HD04HL housings, but you'll spend around $1600-1800 to get it all setup if you buy new, between the T3 housing from ATP, plus the turbo itself and wastegate setup. On a stock head and ported 90+ I have around 5psi by 2500, and full tilt at my spec by 3k (18psi right now). It would certainly come in a little sooner with some better tuning on MS though, and also a good bit sooner with a worked over head. It's also much more linear power delivery than something like the holsets, which allows you to modulate it, rather than waiting for it followed by obliterating the tires.

Last autocross I ran a couple years ago I had just gotten the turbo on and it was actually VERY easy to drive, with boost modulation quite easy and smooth enough to modulate on the long sweepers, keep the rear end right at the limits of the tires, while maintaining spool to get out of the corners.

I am leaning toward the garrett 2871. I am a bit confused by all the options. I would assume the t3 housing is needed If bolting to the stock 90+ manifold...I'd like to see what you did for the wastegate setup.

gsellstr said:

Honestly, with a 90+ motor you've already got decent rods in there, just no squirters. 2.4 will do quite a lot without needing much more than chips. One of the biggest restrictions is the hot side on the TD04HL turbo's, but even so, they still do pretty well. Cams are also a HUGE thing to consider. Personal experience, the VX I had in mine was a damned stump puller and would relieve me of tread without issue by 7-8psi, pretty much on demand, but it was done by 5k. I swapped in the IPD turbo cam which winds out but it definitely is missing the low-end that the VX at 3* had.

As for the recommendation of the Garrett 2871, yeah, I gotta say, it's a badass for sure without the bottleneck of the HD04HL housings, but you'll spend around $1600-1800 to get it all setup if you buy new, between the T3 housing from ATP, plus the turbo itself and wastegate setup. On a stock head and ported 90+ I have around 5psi by 2500, and full tilt at my spec by 3k (18psi right now). It would certainly come in a little sooner with some better tuning on MS though, and also a good bit sooner with a worked over head. It's also much more linear power delivery than something like the holsets, which allows you to modulate it, rather than waiting for it followed by obliterating the tires.

Last autocross I ran a couple years ago I had just gotten the turbo on and it was actually VERY easy to drive, with boost modulation quite easy and smooth enough to modulate on the long sweepers, keep the rear end right at the limits of the tires, while maintaining spool to get out of the corners.

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RoadRacer4Life said:

Stock engine
RSI Stage 3 cam
t3 60/63
upgraded intercooler "anything is better than stock"
nice 2.5 inch or bigger exhaust
Megasquirt
650cc injectors
E85
22psi

315whp 336wtq



Thats what I would suggest


-Sam

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don't listen to the people that've done this or anything..