Modifying Turbo

[Cool Hand Luke]

I guess this could be semi-off topic, as this isnt a question for an RB engine, but the nissansilvia forum is chockers of fully sick kids, and not much technical knowledge...

Im currently in the process of rebuilding my SR20. In its previous form it made 272rwkw on pump fuel with a hks t300 @ 25psi, microtech ecu, and weisco forged pistons.

The turbo's performance is actually quite good, which from memory made full boost around 3700-4000rpm. The main downside is that the stupid amount of boost it requires for the power it makes. On the lower boost setting of 19psi, althought it was never dyno'd when i had the car, the seat of the pants feel isnt much different from the 25 so that tells me the turbo is out of its efficiency range correct?

The engine has been rebuilt with rods, pistons, solid lifters, cams etc, and are hoping for around 330rwkw, and are wondering if say modifying the current turbo is worth its while? I remember reading on here not long ago someone had the housing machined a few mm and picked up 20rwkw or so while just raising its boost threshold slightly? Would getting it rebuilt with slightly larger wheels or housing give more power at lower boost, or being an old school turbo, would i be better off getting a gt3071r?

The new engine's rev limit will be no higher than 9000rpm, so something that made full boost around 4500rpm is fine, as it gives it a 4500rpm usable power band. If a new turbo is the way to go, is the 3071r the best way? if not what?

Edited June 24, 2006 by Cool Hand Luke

[mad082]

i got a mate with a built sr20, and i think (but am not 100% sure) he is running a 3071. he is making around 400hp (300kw) at 19psi.

[discopotato03]

Provided you use the real one and don't go any larger than necessary on turbine housing AR its a good start . The current one (real one) ATM doesn't have an integral wastegate . There is a .82 integral housing version in the pipe but its probably too big for an RB20 . If Garrett make an integral .63 AR version of the GT30 housing it would be pretty good on that turbo but don't expect boost off idle for a 270Kw RB20 .

Cheers A .

Edited June 23, 2006 by discopotato03

[Cool Hand Luke]

Provided you use the real one and don't go any larger than necessary on turbine housing AR its a good start . The current one (real one) ATM doesn't have an integral wastegate . There is a .82 integral housing version in the pipe but its probably too big for an RB20 . If Garrett make an integral .63 AR version of the GT30 housing it would be pretty good on that turbo but don't expect boost off idle for a 270Kw RB20 .

Cheers A .

Hey thats cool, cos its for a SR20 . Have a low mount hks exhaust manifold, with hks external wastegate (not sure what size), and hks t300 on it currently, and it makes 272rwkw now. Im looking for 330rwkw with the new engine, and thought modifying the t300 would be a better option than getting a completely new turbo.

[mad082]

price wise it may work out about the same.

[R31Nismoid]

Dont modify what you have, your gonna be creating a guess work turbo really.

Get something new... im not expirienced with what works on SR's but your gonna need something reasonably big. I dont think a 3071 will get there.

hrm...

[BezerkR32]

Nothing that 75 gas wont fix. For $1500 you can get a wet kit, bottle warmer, NOS filter and guage. Wont have to replace any existing parts on your car, and will give you bucket loads more torque. It is the cheapest and easiest way to make 60kw without losing the driveability of your car. Will make the power with less boost and engine timing. have a serious think about it.

Dont modify what you have, your gonna be creating a guess work turbo really.

Get something new... im not expirienced with what works on SR's but your gonna need something reasonably big. I dont think a 3071 will get there.

hrm...

[Busky2k]

The T3 based GT3071R will get you close to 300rwkw. Unforunately the last 10% to get you to 330rwkw will mean another big step again in turbo charger selection and thus more lag egGT3040R.

http://www.atpturbo.com/Merchant2/merchant...tegory_Code=GRT

I would try the GT3071R. After that, I believe you're just getting too big for an SR20. Just as a quick note, you really need boost to get more power. You either increase the volumetric efficiency or up the boost. Unforunately you cant achieve say 330rwkw on 15psi unless the peak is at something ridiculous like 8000rpm, and the motor has to be damn well set up to achieve such a thing.

[Busky2k]

Also another alternative is the GReddy T67. That has 330rwkw capability on its limits.

[sinistaGTR]

check out nissansilvia.com aswell you might be able to get a lot more help there from the silvia boys to do specific with the sr.

[Cubes]

check out nissansilvia.com aswell you might be able to get a lot more help there from the silvia boys to do specific with the sr.

I guess this could be semi-off topic, as this isnt a question for an RB engine, but the nissansilvia forum is chockers of fully sick kids, and not much technical knowledge...

[Busky2k]

I agree. For every 10 posts on ns.com's tech site there is 1 post thats relavant. I'm a tech mod there and it just shits me off.

[swift_drift87]

The HKS 3037 kit should be able to produce 330rwkw. I remember reading about a guy in Japan who worked for Zeni Tani. He had a purple S14 with that kit and they mentioned it producing 450hp at the rear.

1st post - i just cruise these forums. Seldom/never post.

[The Dan]

The 3071 will be working off it's tits to get you 330rwkw.

Go for a GT30R with a 0.63 rear housing. You'll have full boost by 3700 and it will quite easily produce what you want at 19psi. I have put a GT30R on an SR before and it made 300rwkw on 16psi with conservative timing. It should fit fairly easily onto the HKS manifold. You can get one for $1750

[Busky2k]

Well.. the way I see it is that there is hardly any difference between the power capability of the GT30R and the GT3071R besides the larger compressor which flows a hair more (~2 lb/min). However the GT30R will be considerably more laggy for no huge gain. Gotta watch out going too big on an SR20 or it just becomes a real pig.

[The Dan]

Well.. the way I see it is that there is hardly any difference between the power capability of the GT30R and the GT3071R besides the larger compressor which flows a hair more (~2 lb/min). However the GT30R will be considerably more laggy for no huge gain. Gotta watch out going too big on an SR20 or it just becomes a real pig.

The GT30R flows 200hp more than the GT3071R...why do you think this is a hair more? The GT30R with the 0.6 rear will come on full on an SR at around 3700.....laggy....I think not.

[Busky2k]

200hp more? No way. Maybe 20 hp more. Unless you are thinking of the GT3071 T2 flanged version with the integral wastegate which is definitely not the same and yes there is plenty of difference.

The turbine and rear housing is the same. The compressor is 76mm vs 71mm but the difference is ~50lb/min vs ~52lb/min worth of flow. Thats certainly not 200hp more unless you can get some documentation to prove otherwise?

GT3071R

http://www.atpturbo.com/Merchant2/merchant...tegory_Code=GRT

GT30R

http://www.atpturbo.com/Merchant2/merchant...tegory_Code=GRT

[Cool Hand Luke]

Thanks for the info. The plan was to run a 50 or 75hp shot when its run at the strip anyway, plus if it makes most of its power from gas, then i see it as a bit of a one hit wonder....

I dont mind a higher boost threshold, as it will have a 9000-9200rpm rev limit, as i said. Good power from even 4500rpm, still gives it a 4500-4700rpm usable powerband, and 50% of its total rev limit, which is fine.

The T300 that was on it before i guess could be classed as a bit of a laggy turbo, but when driven correctly i didnt find it a problem except a few times on the street, and that was due to an error on my behalf more than anything else.

[The Dan]

200hp more? No way. Maybe 20 hp more. Unless you are thinking of the GT3071 T2 flanged version with the integral wastegate which is definitely not the same and yes there is plenty of difference.

The turbine and rear housing is the same. The compressor is 76mm vs 71mm but the difference is ~50lb/min vs ~52lb/min worth of flow. Thats certainly not 200hp more unless you can get some documentation to prove otherwise?

GT3071R

http://www.atpturbo.com/Merchant2/merchant...tegory_Code=GRT

GT30R

http://www.atpturbo.com/Merchant2/merchant...tegory_Code=GRT

I'm talking about a Garrett GT3082R which used to be known as a GT30R. Just like the GT35R is now called a GT3582. The GT3082R (SB8006, SB8006A and SB8006B if you would like the Garrett part number) is rated at 600hp.

The GT3071 (700382-3 and 700382-12) is rated at 400hp. You can do the math but on my calculator that equals a 200hp difference. I don't care about ATP turbos....Garrett make them, Garrett rate them.

[Busky2k]

But the GT30R is the "GT3076R" #700382-12, CHRA 700177-7? You can find it on page 32 of the Garrett Catalogue.

The GT3082R uses a 82mm GT35 compressor, so its a hybrid of the GT30 turbine with a GT35 comp.

The Garrett's GT3071R on the website are all the T2 type which are rated around 450hp because they have the cut down 56mm turbine, integral wastegate and T2 flange. In the T3 flange and uncut 60mm turbine config, its then you can get upto 500hp.

Funnily enough they do not list the GT3071R in the T3 housing and the uncut 60mm GT30 turbine. But all you have to do is throw on the T3 housing on the proper cartridge and you're done.

Anyways come to think of it, if he doesnt mind the lag and he can rev to 9000rpm, maybe the GT30R or even larger might have to be the go.

Anyways I'll leave it at that.. gettin messy the thread. Discopotato03 can add some valuable information to this discussion IMO.

Edited June 25, 2006 by Busky2k