Looking for a turbo that will get my 3.4 into the 400hp range. I will lower the compression to around 8 or 8.5-1 and was wondering what would be a good top end turbo? What kind of boost would be needed to get it into the 400hp range?

I really know nothing about trim and other turbo specifics, any info would be great.

Thanks!

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86GT 4 speed
3.4tdc in progress.

has anyone on the forums successfully gotten around 400 hp out of a turbo 3.4 dohc, that''s the question. I don't think I've seen anyone get 400 hp, probly have to run decent boost. Good luck to ya though!

James

Run a To4b with a 60-1 compresor wheel 15 psi should put you at 400 hp

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JM / SH

quote Originally posted by The Punisher: Run a To4b with a 60-1 compresor wheel 15 psi should put you at 400 hp

Yup. On the exhaust side go for a P trim, either .6ish housing for more streetability, or .7ish for more fun.

A 60-1 HiFi, 62-1, T04E 60 trim, T64, or T66 could be used as well.

Thanks guys, I don't know of anyone that has boosted a 3.4 to over 400hp but it shouldn't be to hard with its free flowing heads. Just hard to find performance bottom end parts. A N/A 3.4dohc has more hp than either a 3800 or 4.9, this engine should have all kinds of potential. Just a cam retard will put it in the 238hp range.

I wouldnt use the T04e 60 trim. I had one and It didnt have crap for a 3.8. A T61 would be well suited for a 3.4L with the flow characteristics of the engine. You could even step up to a 62-1 or a T64 if you wanna get crazy . check out www.turbofast.com.au theres some turbo calcs on there, and they will help you figure the best turbo for your setup.

Good luck!

quote Originally posted by fieroX: I wouldnt use the T04e 60 trim. I had one and It didnt have crap for a 3.8. A T61 would be well suited for a 3.4L with the flow characteristics of the engine. You could even step up to a 62-1 or a T64 if you wanna get crazy . check out www.turbofast.com.au theres some turbo calcs on there, and they will help you figure the best turbo for your setup. Good luck!

When we discuss turbo size recommendations, we should distinguish between a strip only car and the street vehicle. I would agree that a larger turbo makes the most peak HP. However, on the street , torque and low end power wins. For the street I would consider using a T3/T4 hybrid turbo for best all around performance. For the strip (where RPM's are kept high) I would go with your recomendation.

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87GT 3.4 Turbo Best 0-60 5.2 seconds
http://www.turbochargerpower.com/turbo.htm

quote Originally posted by Dennis LaGrua: When we discuss turbo size recommendations, we should distinguish between a strip only car and the street vehicle. I would agree that a larger turbo makes the most peak HP. However, on the street , torque and low end power wins. For the street I would consider using a T3/T4 hybrid turbo for best all around performance. For the strip (where RPM's are kept high) I would go with your recomendation.

The DOHC would work best with a peak hp setup. Thats where it makes its power in the higher rpm band. Use stiff gearing

Chris West has a Turbo 3.4 DOHC and its rated at 350hp. Don't know what turbo he used though.

I definitly want power at high rpm, thats what this engine is suited for. Thanks for the link X. I would like to see 400 at the wheels, would copper headgaskets be enough or should the block be o-ringed?

What is the best aftermarket engine management system to use for a turbo engine running 15psi+?

Thanks again!

quote Originally posted by crzyone: According to the turbo calculator, a 3.4 turning a maximum 7200rpm at 10psi boost will make 458hp. It recomends a Garrett GT25 turbo. Anyone know anything about this turbo and how big it is? Same calculator using 14psi boost it says 527hp and a Garrett GT30

Okay not to be ignorant but stock a 3.4L DOHC motor makes 215hp. How in the world is it going to make 458 hp with 10psi of boost? You dont pick up 243 hp with 10 psi of boost. With 10psi of boost on a 3.4TDC motor I would guess maybe 280-300hp at the flywheel with perfect tuning. No way you are going to make that kind of power with only 10lbs even if its a built motor.

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[This message has been edited by Rare87GT (edited 08-04-2004).]

Are you arguing with me or the turbo calculator? I'm just repeating what it said.

GM had these engines running around 270hp before they detuned them because they didn't have a reliable transmission to handle it. Just a timing retard will net 238hp. I am looking to make 400hp at the wheels, what do I need?

quote Originally posted by crzyone: what do I need?

j/k

GM tends to detune a lot of motors I know the 3800sc was said to have 300 HP 300 TQ. To bad they can't pull their heads out of their butts and make a performance FWD transmission. I would think 300-330 with 10 psi, but I haven't researched the DOHC motor, but I did know it was detuned like you said. Wish you luck though which ever you choose keep us updated any kind of insane performance around here is good

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It would make more sense to get 300hp out of the 3.8sc than to get rid of it all together in the bonneville and use a N*, which is also a very detuned engine.

quote Originally posted by Rare87GT: Okay not to be ignorant but stock a 3.4L DOHC motor makes 215hp. How in the world is it going to make 458 hp with 10psi of boost? You dont pick up 243 hp with 10 psi of boost. With 10psi of boost on a 3.4TDC motor I would guess maybe 280-300hp at the flywheel with perfect tuning. No way you are going to make that kind of power with only 10lbs even if its a built motor.

Maybe not 458hp @ 10psi, but pound for pound the LQ1 will make more power per pound of boost then the L67 does. The only exception is a really built L67, but then again the Stage2 or 3 heads that cost over $1k flow about the same as stock LQ1 heads.

I am running a 95' 3.4l DOHC with a turbo. With a pretty good tune at 10 psi, I made ~270 HP at the wheels. That is with a TO4e 46 trim wheel.

Matt

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86 GT, 5-Speed
87 GT, 3.4l DOHC Turbo
95 BMW M3
02 Nissan Altima 3.5SE

For a good all around daily driver that sees a track fairly often, I make an F61 turbocharger that is making some awesome power. On a 3.4 pushrod motor in a 94 Firebird we made 290 rwhp 373 rwtq @ 5psi. The engine has a stock bottom end, stock cam and valve train, ported heads and intake and an LT1 throttle body mated to a 5 speed trans. I sell these for as little as $650.

Also, if you are looking to save a little money, we make a T3/T04E that, on a completely stock internals 3.8 in an 01 Firebird, we put down 349/416 intercooled to the tires at 15psi but limited to 4300rpm. No computer tuning. Also, we made 325/369 non-intercooled at ~13psi on a non-intercooled 3.8 in an 01 Grand Prix GT. This pull was to redline again, with no computer tuning. These turbochargers start at $500.

Personally, I don't use the online calculators. They are good for getting a ball park but I always do the math by hand before choosing a compressor. The online calculators make a lot of assumptions in their math so there is never an exact mathc. Plus there is more to turbo design than matching a compressor wheel.

If you want, shoot me a PM or an email and I'll get with you and spec out a turbocharger.

What about a GT-32 ?

Any opinions?

caddy, what do you think would duit this engine? I want most of the boost in the upper rpm ranges, 5k-7200 redline. Do you sell a turbo that is suited for that kind of airflow to support 400hp?

Thanks for the replies +s

quote Originally posted by crzyone: caddy, what do you think would duit this engine? I want most of the boost in the upper rpm ranges, 5k-7200 redline. Do you sell a turbo that is suited for that kind of airflow to support 400hp? Thanks for the replies +s

I think the F61 would be an awesome turbocharger for you application off the top of my head. It should flow more than enough air to meet your needs. I'm going today to pick up a 'new' 88 GT I just bought so I will be out of the office but I'll work up some numbers for you tomorrow and see what I can get. We sell everything from tiny t2 turbos that people can use on 4 wheelers and such on up to a massive T138 which is enough air to power a low 6 second promod car.

quote Originally posted by THE BEAST: What about a GT-32 ? Any opinions?

Never used one in any of my applications but it should be comparable to something in the mid T3/T04E range. The new Garrett compressor wheels seem to be pretty efficient but a little more expensive (100-200 more than a T04E cold side on a hybrid).

quote ...On a 3.4 pushrod motor in a 94 Firebird we made 290 rwhp 373 rwtq @ 5psi...

Care to post a graph showing that? Not to flame, but 5psi will not net you that much power even with the "mild headwork"...it is a +200ci pushrod engine!!
I do agree with you however turbocalculators are to be used to get ball park figures, you want 400HP call Chris West for an insight, as he has proven time and time again 3.4DOHC turbos are his speciality...leave Force induction to ppl who know it...self prophesized gurus are only self-prophesized gurus...especially in here!! You want 400hp on a 3.4TDC you had better do a lot of homework...the turbo is only a part of the puzzle, there are other issues to contend with. I don't believe you will enjoy a turbo which has an xhaust housing bigger than .69 A/R. Dennis already mentioned it...there is fact and there is fiction. If you want 400HP daily driving/occasional driving stick with something that will be lively and not a short brief window...except of course you only drive on the highway

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3800 II v6 intercooled turbo...CWP!

quote Originally posted by nocutt: Care to post a graph showing that? Not to flame, but 5psi will not net you that much power even with the "mild headwork"...it is a +200ci pushrod engine!! I do agree with you however turbocalculators are to be used to get ball park figures, you want 400HP call Chris West for an insight, as he has proven time and time again 3.4DOHC turbos are his speciality...leave Force induction to ppl who know it...self prophesized gurus are only self-prophesized gurus...especially in here!! You want 400hp on a 3.4TDC you had better do a lot of homework...the turbo is only a part of the puzzle, there are other issues to contend with. I don't believe you will enjoy a turbo which has an xhaust housing bigger than .69 A/R. Dennis already mentioned it...there is fact and there is fiction. If you want 400HP daily driving/occasional driving stick with something that will be lively and not a short brief window...except of course you only drive on the highway

Are you referring to a T3 or a T4 when you say .69 A/R??
Since there is quiet some size differences.

Thanks Caddy, how much does that F61 run?

400hp out of this motor should be no problem. I will be putting forged pistons in it, and the heads should be more than sufficient in stock form. Isn't Chris West using a stock motor with a turbo? I didn't hear anyone mention that he did anything to the bottom end? My swap will be intercooled and if need be I will use water/methanol injection. I had an LT1 I was going to install but for the price of the installation kit I figured I'd get a 3.4tdc and boost the crap out of it.

This will be daily driven, shouldn't be a problem.

quote Originally posted by caddyrocket: For a good all around daily driver that sees a track fairly often, I make an F61 turbocharger that is making some awesome power. On a 3.4 pushrod motor in a 94 Firebird we made 290 rwhp 373 rwtq @ 5psi. The engine has a stock bottom end, stock cam and valve train, ported heads and intake and an LT1 throttle body mated to a 5 speed trans. I sell these for as little as $650. Also, if you are looking to save a little money, we make a T3/T04E that, on a completely stock internals 3.8 in an 01 Firebird, we put down 349/416 intercooled to the tires at 15psi but limited to 4300rpm. No computer tuning. Also, we made 325/369 non-intercooled at ~13psi on a non-intercooled 3.8 in an 01 Grand Prix GT. This pull was to redline again, with no computer tuning. These turbochargers start at $500.

Can you give a breakdown of what is involved in a "No computer tuning" 325/369 non intercooled 3.8? Did this system compensate for the boost just through MAF sensor? I'm assuming this is starting with a n/a engine... that is handling these power levels ok? I'm getting ready to drop a 1998 3800 series 2 out of a Lumina LTZ into a 1988 Fiero Formula. Do you think that 325-350hp is something that it could handle or produce in a daily driven car? My plan is to run the stock engine/stock 4t65e and all the 1998 computer controls from the donor Lumina.

I'd love to see a breakdown of costs for both intercooled and non-intercooled variants. Also what sort of fuel your running at those power levels.

editted cause I can't quote just what I wanted... twice!

[This message has been edited by Scott-Wa (edited 08-05-2004).]

Crzyone. Who are you going through to get your pistons? Im going to need a set of forged 3400 soon.

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http://www.gmpcm.com/

Not sure man, havn't been really looking yet. They must be out there somewhere, the 60* V-6 has been around forever. I'll get ahold of you if I find a good supplier. I think my stock rods and crank should be strong enough for 400hp.

i donno much about turbo's but that i do know is that the t3/t4 hybrid will spool extremely quick and can still handle decent boost just a thought though

quote Originally posted by crzyone: Not sure man, havn't been really looking yet. They must be out there somewhere, the 60* V-6 has been around forever. I'll get ahold of you if I find a good supplier. I think my stock rods and crank should be strong enough for 400hp.

I agree with the rods and crank. Upgrade the bolts mind you.

Ive been looking for forged 660 pistons and havent found anything shy of 500 USD for a set yet as no one mass produces them. Seems they have to be custom ordered.

quote Originally posted by crzyone: According to the turbo calculator, a 3.4 turning a maximum 7200rpm at 10psi boost will make 458hp. It recomends a Garrett GT25 turbo. Anyone know anything about this turbo and how big it is? Same calculator using 14psi boost it says 527hp and a Garrett GT30

Sounds like the turbo calc is @$$uming 100% VE and 100% intercooler efficiency...

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'87 Fiero GT: Low, Sleek, Fast, and Loud
'90 Pontiac 6000 SE AWD: None of the Above

Luck, Fate and Destiny are words used by those who lack the courage to define their own future

[This message has been edited by Will (edited 08-05-2004).]

**** man, you dont have in in yet and your looking to mod it lol

Just building a parts list for next summer I want to get it running before fall and next sprind I will tear it all down and build my turbo motor. I cant wait to have 400hp, I've ridden in a fiero with 430rwhp and all I can say is its insane

quote Originally posted by Scott-Wa: Can you give a breakdown of what is involved in a "No computer tuning" 325/369 non intercooled 3.8? Did this system compensate for the boost just through MAF sensor? I'm assuming this is starting with a n/a engine... that is handling these power levels ok? I'm getting ready to drop a 1998 3800 series 2 out of a Lumina LTZ into a 1988 Fiero Formula. Do you think that 325-350hp is something that it could handle or produce in a daily driven car? My plan is to run the stock engine/stock 4t65e and all the 1998 computer controls from the donor Lumina. I'd love to see a breakdown of costs for both intercooled and non-intercooled variants. Also what sort of fuel your running at those power levels. editted cause I can't quote just what I wanted... twice!

On the L36 Grand Prix...
Yup, the MAF works on it just fine. We were running a mini-AFC with 36lb L67 injectors to modify the MAF signal so the car would idle ok. It is an L36 which originally came with 22lb injectors if I recall. Without the maf and on smaller injectors with less boost It made in the 260 range but I can't remember the details on that.

Here is the video of that run.

http://www.kbsturbo.com/l36grandprix/videos/turbogtdyno1.wmv

The final 438/429 pull was with a 38 jet. The massive increase of power over what the nitrous alone can be attributed to the cooling effect nitrous has. At similar boost levels, and no nitrous, we brought the Grand Prix from a 16.1 to a 13.3. Again, no computer tuning.

On the L36 Firebird(intercooled),
We didn't use an AFC. A booster pump, LS1 injectors and an FMU compensated but as you can see, there are major tuning issues with that. Here is a copy of the dyno sheet. Note the terrible curve on the dyno was attributed to the car running OFF THE CHART rich lol..

Both engines are completely stock as is are both computers. The Grand Prix did eventally take the chuck off one of the pistons after about 6 months. A stock short block replaced it and it's living fine. The Firebird remains completely stock and *knock on wood* has not blow up anything. It's got a year and a half and over 20k on the kit.

If you are looking for a turbo system for a 3.8 fiero, LMK. When I finish mine, I will have something to mock up parts off of and could sell you some peices to make it easier.

[This message has been edited by caddyrocket (edited 08-06-2004).]

Thanks again Caddy!

Since you seem to know alot about turbos and turbo engines, how much power do you think I could pull from a stock 3.4dohc with just adding a turbo and intercooler? I'm guessing somewhere between 5-7psi but have no idea what kind of hp gains I would get from that.

Thanks again!

Caddy rocket...I know who you are (from the f-body board/clubgp under a different banner...lol) and "the self prophesized guru" remark isn't directed towards you but rather a generalization...

Anywayz, a video is still only that a video...a graph will show the minimal band I believe this HUGEmongous turbos (ppl have started to claim is the "right turbo") will generate...the 3.4DOHC "might" benefit from a big hairdrier, but there are other issues associated with running them...and also a 3.4 pushrod will not produce 373 Ft/lb TQ with 5psi on that turbo anywayz (maybe with a lil squeeze?), I am sorry the math doesn't work out for me!! Like I said No flame just MY OWN logical standpoint...I will stand corrected when I see a connection ...
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3800 II v6 intercooled turbo...CWP!

[This message has been edited by nocutt (edited 08-06-2004).]

Crzyone- If you can use the 7730 PCM I have a spare. Its actually a 6344 but same thing different chip. It will mount in the factory location also.

I demand a pic resize!! I want to read this thread.

And btw, donk, Putting the 1227730 computer, with coilpacks, and the 2 bar map was the START of a project.

And this is the finish of it.