Turbo opinion and streetability??

[Slippi84]

I"m not gonna post the brand and if you know I would apreciate not syaing so as I want this to be more about the turbo's size and trim and .ar vs brand performance and what not. Below is the stats of the turbo I"m thinking about giving a shot. This will be a car that is street driven 97% of the time but I want to be able to put down 400whp on pump gas. By looking at the size specs of the turbo do you think that is a reasonable goal. If you know a turbo that has comparable stats chime in that woudl make it easier for me to make my descision.

!!!! I have a 420a not a 4g63 motor. I am fully built with high compression motor so spool should be a little faster than a basic 4g63 setup but I will limited in how much boost I can run!!!

Specifications:
Compressor: 50 trim 0.70 A/R

Compressor Inducer: 64.8 mm

Compressor Exducer: 91.4 mm

Compressor Inlet: 4” hose connection

Compressor Outlet: 2.5” hose connection

Turbine: 58 trim 0.63 A/R

Turbine Inducer: 73.4 mm

Turbine Exducer: 55.9 mm

Turbine Inlet: Standard T3 4 bolt flange

Turbine Outlet: 3" 4 bolt round flange

Center Housing: Oil cooled

Bearing System: Journal bearing

Wastegate: External

[pneumo]

That's a big turbo. You'll get plenty of lag on the street. Typically, a turbo with a 65mm compressor wheel is a drag race only item. For comparison, a GT35 has a 61mm compressor inducer.

It's odd that the turbine wheel has such a small exducer given the size of the compressor and the size of the turbine inducer. This might help spool a little, but it'll also choke off the overall flow.

[Slippi84]

Originally Posted by pneumo

That's a big turbo. You'll get plenty of lag on the street. Typically, a turbo with a 65mm compressor wheel is a drag race only item. For comparison, a GT35 has a 61mm compressor inducer.

It's odd that the turbine wheel has such a small exducer given the size of the compressor and the size of the turbine inducer. This might help spool a little, but it'll also choke off the overall flow.

That's what I thought and was hoping they have this same turbo with a .48ar hot side too but I felt that would be too small but again this is a street car.

[flyboy346205]

Considering the motor you have, that's way to big. Especially with only a 400 hp limit. If i were you I'd go with something more like a Garrett GT2876R which will have some decent spool up, or, if you want to be able to push a little over 500hp eventually, the Garrett GT3071R, which will also still have decent spool up. On top of that they ball have ball bearing center sections. They still have the same A/R on the turbine side but that won't matter much with ball bearings.

Another thing I'd be worried about running as big of a turbo as you have posted is compressor surge. Definitely keep that in mind. And if your motor is high compression but is built then you don't have to run too low of boost levels.

[Slippi84]

Originally Posted by flyboy346205

Considering the motor you have, that's way to big. Especially with only a 400 hp limit. If i were you I'd go with something more like a Garrett GT2876R which will have some decent spool up, or, if you want to be able to push a little over 500hp eventually, the Garrett GT3071R, which will also still have decent spool up. On top of that they ball have ball bearing center sections. They still have the same A/R on the turbine side but that won't matter much with ball bearings.

Another thing I'd be worried about running as big of a turbo as you have posted is compressor surge. Definitely keep that in mind. And if your motor is high compression but is built then you don't have to run too low of boost levels.

That made no sense. WHat do you mean for my motor that's way to big. I have the same displacement as a 4g63 and yes I a built how else would I have high compression pistons?? Neither of the turbo's would do over 500hp without meth or race gas. I want this turbo to make 400whp reliably on pump gas and spool by 4500 by debat enow is to get the .48ar and sacrafice spool or do I hope my higher compression pistons will help a little with spool and get the .63ar and have a much better top end?

[pneumo]

Do you mean you've decided to go with the turbo listed in the first post?

[Slippi84]

Originally Posted by pneumo

Do you mean you've decided to go with the turbo listed in the first post?

I haven't decided anything yet. That's why I made this thread lol

[flyboy346205]

Originally Posted by pneumo

Typically, a turbo with a 65mm compressor wheel is a drag race only item.

This is what I meant. It's too big for street ability. I should have clarified that. If you want street ability then why are you looking at spool up around 4500? You shouldn't ever see that on the street if we're talking about normal every day driving. It's nice to have that for a drag application but look for a spool up around 2500-3500 for really good street ability. This will get you a lot of fun and still be able to hit your mark of 400 hp without a hitch. On top of that, when you do go to the track to race you will get full boost just that much quicker and that can make all the difference in a race...

[Slippi84]

Originally Posted by flyboy346205

This is what I meant. It's too big for street ability. I should have clarified that. If you want street ability then why are you looking at spool up around 4500? You shouldn't ever see that on the street if we're talking about normal every day driving. It's nice to have that for a drag application but look for a spool up around 2500-3500 for really good street ability. This will get you a lot of fun and still be able to hit your mark of 400 hp without a hitch. On top of that, when you do go to the track to race you will get full boost just that much quicker and that can make all the difference in a race...

I meant full boost by 4500. Usualy from my experience a turbo capable of making 400whp on lower boost levels usually hits full boost around 42-4500rpms. Even though I'm built I have 10:5:1 compression which will limit how much boost I can run. I'm aiming for 15psi on pump.

[Slippi84]

The same company offers this turbo I think this will be a lot better for my goals and it's rated to 500hp.

Specifications:
Compressor: 50 trim 0.50 A/R

Compressor Inducer: 53.5 mm

Compressor Exducer: 75.5 mm

Compressor Inlet: 3.5” hose connection

Compressor Outlet: 2.5” hose connection

Turbine: 73 trim 0.63 A/R

Turbine Inducer: 60.8 mm

Turbine Exducer: 52 mm

Turbine Inlet: Standard T3 4 bolt flange

Turbine Outlet: 2.5" 4 bolt round flange

Center Housing: Oil cooled

Bearing System: Journal bearing

Wastegate: External

[pneumo]

That one looks much better, after all it has the famous 50 trim compressor. The exhaust wheel is a little small, but that's not terrible. The .63 A/R housing should let it flow well.

[Slippi84]

Originally Posted by pneumo

That one looks much better, after all it has the famous 50 trim compressor. The exhaust wheel is a little small, but that's not terrible. The .63 A/R housing should let it flow well.

Yeah I'm worried about it being too small though. But like you said it the pump gas king 50 trim compressor and I'm having Nate tune it for me so I figure if he can get 400 out of a 16g with pump gas this thing can make 400 on pump too.

[99gst_racer]

I ran the second turbo that you mentioned, and I made 400 WHP on a stock 4G63 engine. You should be just fine with it.

[Slippi84]

Originally Posted by 99gst_racer

I ran the second turbo that you mentioned, and I made 400 WHP on a stock 4G63 engine. You should be just fine with it.

Did you make it on pump or race?

[99gst_racer]

Originally Posted by Slippi84

Did you make it on pump or race?

I did it on race gas. But, if I hadn't been working with so many stock, performance hindering parts, then I feel I could have made the same power on pump gas.

[Slippi84]

Ok let me be more reasonable and list the mods in a easy to read form in case my profile is kinda confusing:

97 eclipse GS 420a motor
10:5:1 Weisco Pistons
Eagle H beam rods
Ported and polished head
Obx intake manifold port matched
Q45 TB
Crower Stage 2 3/4 race cams
Crower spring/retainer kit
3" full N1 Style exhaust(no cat)


The main factors that are making this a harder call is teh 10:5:1 compression and stage 2 cams

From talking to SBR and a couple other companies it looks like 15-17psi is the max that can be run without dealing with crazy knock on 10:5:1 compression on pump gas. So unless I get meth injections the turbo I pick has to make the power i'm looing for at those psi levels. I really think meth migt be my only option on this.

[99gst_racer]

Well, your engine is set-up better than mine was when I ran this turbo 2 years ago.

The only issue that I forsee is running that low boost. I was around 27 psi to make 400 WHP.

[Slippi84]

Originally Posted by 99gst_racer

Well, your engine is set-up better than mine was when I ran this turbo 2 years ago.

The only issue that I forsee is running that low boost. I was around 27 psi to make 400 WHP.

Yeah well it looks like it's meth and pump gas for me.

[NewTurboTuner]

Turbo's like low compression better.
If you want pump gas power, then don't get a high compression ratio. It's easier to make power with low engine compression + more boost....... as oppose to high engine compression + less boost.

The Turbo specs you posted is of a pretty big turbo. It'll probably hit 20psi around 5000rpm or later in 3rd or 4th gear. It's too hard to tell just by looking a specs. Try to find a person who has it, and check out the (real world) performance.

I never was a specs guy when it comes to turbo. I can read the specs just fine, but it just dosent seem to add-up as easily..... as oppose to looking at real world performance #'s.

My best advice would be too get your goals together. Do a brain storm about everything you want. Write it down. (sometime the goals just can't mix-match like a person wants them too)

If all you want is 400awhp and good spool..... then I'd say get a 20g. It'll hit quick and hard!
If you want to build for future power (like 500awhp) then get a FP3052.

Something in that area

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Also where (at what RPM) a turbo hits full boost is relative.
Full boost in 1st gear? Full boost in 2nd, 3rd, or 4th gear? It makes a big difference.

Currently I have my car set at 24lbs of boost.
My FP3065 will hit about 20lbs in 1st gear, 21lbs in 2nd, 23.5lbs in 3rd, and finally 24lbs in 4th/5th. In each gear the boost comes on at a different RPM. In 3rd gear I see 23+lbs boost around 4500rpm, but in 1st gear I bet I don't get 21lbs until about 5500RPM.... (and can that even be called full boost if I hit 22lbs and its set at 24lbs?)

Theres alot that most people never think about when asking general questions.

My best advice is to really think about what you want. Write it all down, and then look into real world performance, and go with what works