I just dropped my S off at the shop to upgrade with a bigger turbo. I am planning on a GT35R but was wondering if anyone has tried a GT40R yet. I will be running 16psi for now until I fully rebuild my motor. So I am trying to decide if I will be happier with a GT35R or a GT40R at 16psi. I am looking for rolling power so lag is not the biggest issue to me but I wonder what the lag difference would be between the two? My current mods are listed below and with my 8.8:1 lower compression, I want a turbo that will make great power at 16psi. Please let me know your opinions. I need to make a decision in the next day or two.

 

Im hoping to have mine up and running over the next week; You should see full boost by 5500-6000 rpm, but with WAY more kick up-top. We can get these turbos within two days if you cant find any, PM for pricing, etc. Just make sure you have the turbo BEFORE You build any hard-parts; this thing is HUGE. Look at the clearance between the turbine housing and VTEC selenoid...what clearance?

 

I guess we will witness the first melted VTEC selenoid Cody

 

Ive got a few tricks up my sleeves Them cheap aluminum flashing heat sheilds are exactly that; but they sure do WORK

oh, there is around .100" clearance; I wouldnt be surprised if that clearance shrinks when the turbine housing gets hot though.

 

^ Very nice. Which turbo would you prefer at 13-16psi? I will be running a street setting at around 13psi on 91 octane and a race setting at 16psi on 100-109 octane. If the GT40R sees full boost at 5,500-6,000rpms, do you know what the GT35R hits full boost at? And what the power difference between the two would be at 16psi?

Also, would having a stiffer spring in the wastegate, like a 12psi spring make a difference in spool-up time? And with the Greddy Profec E-O1, is it possible to program and tune it to help quicker spool-up?

I have so many questions and want to make my decision by tomorrow .

Thanks

 

I'm hitting full boost at around 4700 rpm with my standard 60-1 turbo and supposedly with the GT35R I can expect full boost at around 4000 rpm.

 

I would expect it to hit later than 4000 rpm with lower compression; I think the 35R will hit 12psi at around 5200 or so, starting to boost at around 3500rpm.
I would much rather have the 40R just because the dynos that I have seen prove that its a WONDERFUL turbo all-around, and that it can make around 800whp with the spoolup slightly slower than the GT35R thats good to 600whp. So Id use the GT40R if you can afford it, as it is more pricey.

 

Ihave a GT35-r but going to go with a 40R for next year...

 

Oh, that's right, he's running lower compression than I.

 

so what manifold with hold both of these turbos?