Okay it is getting to the point where I have to purchase a turbo for the engine I am building.
2.8 stroked to 3.1 with a .030 overbore CR will be slightly lower than 8.5 (because of gasket) Will be using the Saab intercooler Hope to run approx. 10psi, possibly 12psi if everything goes well.
I know the Garret T-3 comes highly recommended but there is also a hybrid of this. What would be best?
Okay it is getting to the point where I have to purchase a turbo for the engine I am building.
2.8 stroked to 3.1 with a .030 overbore CR will be slightly lower than 8.5 (because of gasket) Will be using the Saab intercooler Hope to run approx. 10psi, possibly 12psi if everything goes well.
I know the Garret T-3 comes highly recommended but there is also a hybrid of this. What would be best?
Design1 uses(used to?) the IHI RHB52, it will flow 12psi on a 2.8. A variant of this the IHI VF-8 it will flow 450cfm and go up to 15psi. New cartridges are $550 and if you buy the complete cartridge, compressor and turbine housing you are looking at $750-$800. The Turbine housings are the same on both, but the compressor housings are different. The VF8 is used overseas for some Suburu applications. Don't know that much about the Garret T-3......Paul
[This message has been edited by Paul Prince (edited 07-18-2003).]
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12:02 PM
RotrexFiero Member
Posts: 3692 From: Pittsburgh, PA Registered: Jul 2002
I'm putting a T3 on mine, an 87GT 2.8....no other engine mods. It's a good fit and easy to install. Good luck!
Phil
------------------ 87 FIERO GT 2.8 5spd 0-60 in 6.8 seconds! 87 FIERO CPE 2.5 5spd 86 FIERO SE 2.5 AUTO 87 FIERO GT 2.8 4SPD If you found my advice helpful, please take the time to give me a positive rating. Thanks
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01:02 PM
Dennis LaGrua Member
Posts: 16020 From: Hillsborough, NJ U.S.A. Registered: May 2000
I'm putting a T3 on mine, an 87GT 2.8....no other engine mods. It's a good fit and easy to install. Good luck!
Phil
Word to the wise. You cannot just bolt on a turbo and go. PRECISE Engine management and tuning is super CRITICAL on any turbocharged engine. You must re-calibrate for proper fuel and timing managment via new engine controls or the engine will go BOOM!! Not trying to sell you anything just give you good advise.
I am using a Subaru WRX STi Ver 7.0 turbo. Or rather, the US WRX upgrade turbo.
Its an IHI VF34. The turbos that came in the kits were IHI RHB5, very tiny cute units. The IHI I am using is a bit bigger, and would probably be suited quite well for your 3.1. I'm going to be using it on my 2.8 however.
I plan to run about 12lbs of intercooled boost.
------------------ --1986 SE V6, Wild Custom Notchback --1984 SE Modified Notchback
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06:40 PM
Jul 20th, 2003
RotrexFiero Member
Posts: 3692 From: Pittsburgh, PA Registered: Jul 2002
If I wasn't such a stubborn person, I would just spend the 25-hundred for a complete kit from Dennis. He certainly seems to have the best bang for the buck of all the kit guys.
I will have less than 15-hundred in my setup with all new parts. But, when you figure my time researching, chasing parts, doing crap over? With a good kit, you (can) be done in a weekend. I may be done by this time next year.
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04:35 PM
RotrexFiero Member
Posts: 3692 From: Pittsburgh, PA Registered: Jul 2002
My car is setup for forced induction and I will probably run my Rotrex charger first. That is unless I find a good turbo. Mounting and fabricating a exhaust I dont believe will be that difficult, plus I have the help of a local garage.
Is the Subaru Turbo too small? I mean there is a difference between a 2.4 liter engine and a 3.2 or even a 2.8.
Yes it is water cooled. Its capable of over 350+ on the WRX. It seems it should be quite adaquate. Its much bigger than the very tiny RHB5.
"Another Subaru factory affair, this Turbo is installed on the latest edition STi version WRX from Japan (to 10/01). The VF30 represents the best bang for the buck Turbo to be used for street and strip use. The VF30 features an identical RHF55 housing as used in the larger VF22 which makes upgrades to the wheel increasingly easy. In terms of size, this turbo is almost as large as the VF22, and bigger than the VF23-29. This turbo features the venerable EZ18H turbine housing, 48 mm compressor inlet, and a compressor that while similar in design to the VF23-29, features a 6th blade for better performance across the rev range. This is a terrific all arounf turbo, and clearly our top seller. It's main characteristic is its linear power delivery, making it a perfect bolt on street turbo that can easily turn 12 second timeslips at the strip."
------------------ --1986 SE V6, Wild Custom Notchback --1984 SE Modified Notchback
As a general FYI, just because a turbo is capable of supporting X horsepower doesn't make it a suitable fit for any car. You need to look at the compressor maps to make sure you are in the sweet spot for effiency. A turbo that makes 400 HP on a 2.0l engine probably won't be optimum for a 3.4l engine. If they both made 400 HP, the airflow would be similar, but the pressure ratio would be way different. Do your homework before you purchase and you won't regret the results.
Being a Design One kit owner, I'm quite aware of the small size of the IHI RHB52 turbo in the kit. Design One did this to ensure little to no turbo lag as the small unit spools up very quickly and provides pretty seemless power delivery.
However, while being a good upgrade for a stock 2.8, I'm realizing that eventually this size of turbo will ultimately limit the power of the engine, especially if I eventually go to a 3.1L or 3.4L block, as the increased air requirement will probably overwork the turbo.
Is there any way to figure out what would be the (if any) bolt-on upgrade path for the IHI RHB52 turbo? I figure there has to be another bigger IHI turbo that has the same inlet and outlet locations with the same exhaust mounting flange (I really don't feel like butchering the kit to go with another turbo make) since it looks like IHI makes a boatload of different turbo variants, but how would I go about determining which would be the right one?
Ken S.
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03:28 PM
Paul Prince Member
Posts: 2935 From: Kansas City, MO Registered: Dec 2002
Being a Design One kit owner, I'm quite aware of the small size of the IHI RHB52 turbo in the kit. Design One did this to ensure little to no turbo lag as the small unit spools up very quickly and provides pretty seemless power delivery.
However, while being a good upgrade for a stock 2.8, I'm realizing that eventually this size of turbo will ultimately limit the power of the engine, especially if I eventually go to a 3.1L or 3.4L block, as the increased air requirement will probably overwork the turbo.
Is there any way to figure out what would be the (if any) bolt-on upgrade path for the IHI RHB52 turbo? I figure there has to be another bigger IHI turbo that has the same inlet and outlet locations with the same exhaust mounting flange (I really don't feel like butchering the kit to go with another turbo make) since it looks like IHI makes a boatload of different turbo variants, but how would I go about determining which would be the right one?
Ken S.
The VF-8 has the same turbine housing. Important because you don't have to mess with the Design1 crossover pipe. The compressor housing is different i.e. larger. to pull in more air, and it does not have a intergral male inlet housing, you would have to make one. But I had it on a 3.2 liter and could get 18psi. You may be able to find one that flows more than the VF-8, but if the turbine housing is different, you will have to make some major mods to get it to fit. Any turbo that flows more air would have a larger compressor wheel and opening....Paul
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04:07 PM
RotrexFiero Member
Posts: 3692 From: Pittsburgh, PA Registered: Jul 2002
So I surmise from this thread that the Subaru turbo is not the best purchase for my 3.2 project. Simply because it is too small and I would be back into a similar situation that I am now with the Rotrex (only 7psi).
What about the Garret T3 versus the hybrid offspring?
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05:15 PM
Matt Hawkins Member
Posts: 586 From: Waterford, MI Registered: Oct 2000
RotrexFiero - The big problem with turbocharger selection is knowing what the flow effeciency of your engine is. You use that to determine the approximate pressure ratio versus flow. From what you have written, I think a Garrett T3 with a Super 60 wheel would be just right. If you are looking for one, I have a friend with one on the shelf. I will see if he is willing to part with it and for what price.
Matt
[This message has been edited by Matt Hawkins (edited 07-21-2003).]
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07:47 PM
Alex4mula Member
Posts: 7410 From: Canton, MI US Registered: Dec 1999
Matt, I would very much appreciate that...it would be a big help since I have the engine out I can position and fabricate a mouting bracket much easier than once it is in the car. I love the support I recieve on this forum.
I would just like to say for those considering a turbo for there 2.8/3.4. If you have never driven a Fiero with more than stock power it is a great experience. Once I installed my Rotrex charger I was getting around 3psi (induction pipe leak) and I really thought the car was going to fly off the road. There was such a huge difference in power. A turbo kits is a great upgrade that can be added in a weekend and is worth the time and money.
Rotrexfiero - I am having my friend bring the turbo over so I can verify what it is. I know it is brand new, never used. He is asking $350 for it. If it is what he thinks, it is worth the price. I will let you know.
