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hey everyone about to start a rb26dett r33 gtr v-spec build. i have got so far.

3.5 inch exhaust

3 inch dump pipes

apexi air pods

splitfire coilpacks

boost increase to 14psi

tomei 260 type b cams

tomei cam gears

haltech platinum pro-plug in

any recommendations on where i should be going after this.... aiming for atleast 450-500WHP

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definitely going to need to change your std turbos, as stated -5 or or even -9 will make 450hp, depends what kind of package you want (response or overall power)

stock bottom end will also hold your wanted power level, question is for how long....

aiming for atleast 450-500WHP

Bottom ends still standard. I've heard there pretty good for around 600 hp is this true?

Well you do realise 600hp is pretty close to 500rwhp yes?

So if you've heard they are "good" for 600hp, and you want as LEAST 450-500rwhp - you'd certainly be pushing things gonig by that.

That said there is no magical "safe" number for power. Depends on the age of the motor, use of the car, previous life (generally unknown), tune etc etc. Basically how long is a piece of string.

End of the day i use a rule like this.

Can you afford to break it and the associated rebuild (AKA: The $10,000 adventure)?

If you answered NO - stick to Garrett -7s or -9s with 300-330rwkw (400-450rwhp)

If you answered YES - go for bigger Garrett -5s or a GT3788 370-400rwkw (500-550rwhp)

Ok thanks for the advice really appreicate it. What do most of you's decide with turbo upgrades.

1. Stay with the twin turbo set up

2. Single turbo set up

Could you please state your reasons why you decided to go which way.

Thanks again

Edited by Rumpig

Im pretty sure you have to make that decision for yourself mate.

Just ask yourself basic questions

What do you want out of the car?

Dyno Queen?

Response machine?

Good power with good - average response?

Me for example, I will be going -7's because I want response and car will be mainly street driven. And they will get me where I want to be until its time to rebuild :).

Google search is there for you.

Im running a GT35 single on my stock rb26 with poncams, safe/conservative tune on 20psi is netting me 485hp at all 4 hubs. So thats around 450rwhp. Could push 1-2 more psi but im happy with the power!

I was running a pair of -7s and i was struggling to make over 300kw without pushing the turbos too far (21psi) on the same dyno. Only difference was stock cams.

Single > -7s. Cant comment on -9s but im told they are quite similar in terms of top end power.

I rather make a comfy 450rwhp on a big single as compared running a pair of -7s or -9s to their limit to reach 450rwhp, which i doubt u will get anyway.

Also, the single setups are easier to work on.

Oh and im getting better response with the GT35 as compared to my -7s too :)

The only reason why I would consider sticking to twins is to retain the "stock" look but tbh, the benefits of the single outweigh the want for the stock look, big time.

Cue, single vs twin debate....

Oh and im getting better response with the GT35 as compared to my -7s too :)

Cue, single vs twin debate....

If im reading your comparo graph right... Your -7s were only making 220rwhp (165rwkw) @ 4500rpm ?

If this is correct, then you had an serious setup issue. Possibly boost control.

You should have had a result around 350rwhp (260rwkw) @ 4500rpm. Quite a whopping difference to say the least.

A correct/working result would actually the -7s more responsive than the single. Given a GT35 is larger than a set of -7s, that makes reasonable sense in the broad world of comparison with this type of thing.

So not really a fair of debate single vs twins if you are comparing a working set-up with one that isn't working :)

Fact; 7's wont make 500rwhp.

Fact; Most -9 results also fall short of 500rwhp, well sorted engines (read: big dollars spent) get close 350rwkw

To the OP: all the info is on here that you're asking for. 5's are the turbos to get you the hp you want without any unrequired spending or making your car an easy target for police.

Im pretty sure you have to make that decision for yourself mate.

Just ask yourself basic questions

What do you want out of the car?

Dyno Queen?

Response machine?

Good power with good - average response?

Me for example, I will be going -7's because I want response and car will be mainly street driven. And they will get me where I want to be until its time to rebuild :).

Google search is there for you.

Well said

If im reading your comparo graph right... Your -7s were only making 220rwhp (165rwkw) @ 4500rpm ?

If this is correct, then you had an serious setup issue. Possibly boost control.

You should have had a result around 350rwhp (260rwkw) @ 4500rpm. Quite a whopping difference to say the least.

A correct/working result would actually the -7s more responsive than the single. Given a GT35 is larger than a set of -7s, that makes reasonable sense in the broad world of comparison with this type of thing.

So not really a fair of debate single vs twins if you are comparing a working set-up with one that isn't working :)

Fair call, it is possible that something was wrong but im done thinking about it, the turbos were fine when they came off, the acuators were checked twice, correct preload, balanced while on dyno etc so im not sure what else could have been the issue.

An interesting comparison would be between a pair of -5s to a GT35 setup.

21psi is "too far"?

LOL

Not being rude, but that made me laugh.

I didnt say 21psi is too far.. I Re-read what i wrote, i see how u mis-read that, my bad.

I made 300awkw at 21psi (bleeding off to 18psi at redline) with my -7s. This being my personal experience, i am certain that if you want to hunt for the power level that the OP is after, they -7's will be pushed way beyond their effeciency range (too far). Hence why i said that -5's would be a better choice over -7s or -9s.

All of my tuning ventures have been on 98ron fuel so forgive me for being more conservative than you eastern staters with e85. Yes im jelly that you have it on pump and we dont but we shall not go there :)

I always use 98 when posting stuff, as do most, kinda a given.

Usually people post/make note of E85 when used.

-5 and GT35 would be much closer/interesting I agree.

Pity you -7 setup was down nearly 100kw at 4500 tho, would've really been crappy to drive!

Yeah i know! I grew tired of the lack in response and top end power although the mid-range wasnt too bad but now my car is making good power everywhere so im happy and not complaining :)

If anyone has a gt35 vs -5 comparison on the same dyno please share!

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