Lithium

Hi all I have been lurking around the SAU forums and gaining information from here and other places from before I owned my R33 GTS25t up until now, and will no doubt continue to. I had (and many others will still) have researched and pondered furiously the not so age old "What turbo should I go for question" and I have ended up with a combination that is so far PERFECT for my needs. Its been brought to my attention that people have been following my progress, and others - and that it might be handy to post my findings.... so here goes After all my research I ended up shortlisting and considering long and hard the HKS GT-RS, the 56Trim Garrett GT3076R, the Garrett GT3071R (which I consider to have been NARROWLY my second choice), and a Holset HX35 (got ruled out when I figured I probably wouldn't fit it low mount). After all my deliberation, I ended up with an initial "winning combination" which consisted of: - Garrett GT3076R with .63a/r Ford Style turbine housing (yay ATPTurbo) - Factory Exhaust manifold with 10mm spacer (needed to clear rocker cover), wastegate mounted off the turbine housing of the turbo (BAD move - don't do it, boost creep galore) - Completely stock RB25DET - Nismo 555cc Injectors (yay Greenline for particularly good service on getting these to me) - Walbro 255lb/hr in-tank pump - TiAL 38mm External wastegate - GTSLink Plugin ECU - Cheap front mount intercooler kit - 3.25" MomoCorsa Exhaust with no cat This setup had a MAJOR boost creep problem, even after porting out the internal gate port the Ford Style wastegate setup provided - it rather sucked. I also ended up with huge ignition breakdown issues which was a big pain in the arse. Nonetheless - here are some pics of this stage being put together and running: Turbo: Turbo test fitted (note spacer): Internal gate housing with ported out wastegate feed: Wastegate fitted to turbo: Engine bay with it all in: end of stage one.... will start writing stage two going straight away..

Stock S2 RB25DET GT3076R .82a/r Internally Gated 1bar boost 600x300x76 Intercooler 555cc Nismo Injectors Walbro Fuel Pump Safe tune

Haha will do that on the dyno (maybe not to 18psi though haha) Thanks HEAPS for all your help! I'd still be trying to find a way to solve my boost creep issue if it weren't for you

Just installed one of these .82a/r IG housings on my GT3076R, its awesome Initial tests show it to hit and hold 13psi SOLID from around 3500rpm all the way through 4th. Going to have it on the dyno on Thursday for a proper tune.

Oh it'll probably have the VQ37HR thing in it - those are pretty damn grunty motors! That'd go damn well!

I couldn't possibly disagree with this all more. S13 + stock internal RB25DET with an upgraded turbo etc is a proven 10s combination at the drags. Even an RB20DET makes a hell of a fun car to drive, if its going into what was originally the CA18. Going by the fact you mention the handling, I am better you have not actually driven an S13 with an RB in it? It is a comment made often and I've never heard it made by people who've actually tried driving one. There are quite a few top NZ drift cars using RB powered S13s, even in Japan its done.

Very nice!! And the calender girl is fantastic!

On the contrary, not at all. They all read too different.

Yep. I think the "more boost, smaller gate" theory is a bit whack. You basically need enough wastegate to drop the turbine pressure sufficiently to stop spinning the turbo more. GT4088R on an RB25 is an interesting combination - what is the spool like?

Hey man - don't confuse slightly longer spool times with less torque. You will have less torque until its fully spooled of course - so strictly speaking maybe a bit less torque at cruise (<3000rpm) engine speeds, but thats why they are cruise engine speeds. Who races at <3000rpm? Peak power should be reached at the same revs ideally, a bigger turbo can start making more power at lower revs if the smaller turbo is maxed out, or if the bigger turbo is running more boost though.

Have you seen higher than the 310rwkw @ 20psi mentioned in this thread for a GT2835 from a GT-RS?

OK a GT2835R is like an equivalent of a GT3071R from Garrett, more or less the same thing. It basically should flow a bit better than a HKS GT-RS, they use the same compressor but the GT2835R has a bigger comp housing and a bit more turbine wheel if I remember rightly. GT-RS will have much less lag than a GT3076R, but will be working hard to make 270-280rwkw. You are right about HKS being a good option given their turbos are a straight bolt on. From everything you say, I'd go for a GT2835 from HKS - pretty much a bolt on fix if I remember rightly. A GT-RS seems most at home around 250-260rwkw from the threads I've seen. Garrett do an internally gated T3 version of the GT3071R and GT3076R, I'd be looking seriously at the GT3071R from what you've said.... I reckon it'd be really really well suited to it. With a .82a/r turbine housing it'd spool fairly quickly and smoothly, and should be able to do 300rwkw without TOO much more lag than a GTRS. You'll need some custom stuff made up, but its not a new manifold etc type situation. Cubes has done an internally wastegated Garrett GT3076R on his R32...

I'm finding him a bit irritating as a tuner from a few of the things you have mentioned about him haha. Chalk and cheese is funny, as a GT3076R from Garrett IS a HKS GT3037. Or the other way around if you want. Made in the same factory, same wheels and core. It'll spool the same-ish. The only reason there could be any varience is that HKS do 8cm/10cm/12cm style turbine housings while Garrett are .63, .82, 1.06 so they're on a slightly different scale. Other than that, its all just looks (ie, HKS label on the compressor cover etc...). I vote the GT3076R, HKS GT-RS and GT3071R are right up at the max out area of their efficiency at 300kw @ wheels whereas as you say, its beneath a GT3076R. You don't want to be maxing your turbo out to make the power you want, a GT3076R spools fairly well still (.63 a/r is a bit snappy, but in a fun way haha) but has head room for if you do get a little greedy in future etc. I would not go for a GT-RS for a 270-280rwkw R33, personally. It'd be working too hard and working the motor too hard.

The compressor wheel IS a problem on the S2s, quite a few people have had them break under duress. I'm one of those

OK my bad, I must have been put wrong somewhere - I definitely have been put under the impression he had the record for quickest manual shifted.... nonetheless its completely unrelated, and would regardless take nothing from this car doing a 8.69 on DOT tires What is the setup?

Actually I think you are sortof right, the Croyden's GTR WAS a Hollinger sequential - I got my wires crossed, Glenn Sucklings OWN R32 GTR was a manually shifted Hollinger box - running full drag slicks though. The fastest manually shifted GTR I believe, think thats how I got confused.

I can't remember what tires the Croydens R32 was running when it was there, but it was done using an H-pattern box too - and they were definitely some kind of DOT approved tyre. I have it in my head a UAE R32 GT-R built by Sub Zero did something like an 8.2 or 8.3 on DOT tires as well? Either way, an 8s run in ANY form with a 4WD is absolutely nuts, well done - thats awesome news. The 8s GTR club is a very exclusive one

Stock for stock the Z narrowly down the 1/4, and by a solid margain on the track.

Congrats on the awesome time Look forward to seeing how much quicker it goes Quickest RB25 powered thing in the world?

Awesome Thanks! Here's hoping its a RB25DET for a change.

As usual I look on the Honda forums to see what combinations are worth looking at. They are a crazy bunch and have tried everything. Here are a couple of threads with respectible results with a GT3567R and a GT4088R on about as even playing fields as I can find. Not perfect, but you get a rough idea of spool etc.... There are comments on there (especially the GT3567R dyno thread) which basically imply that while it can give good power, the GT3567R is not worth while going to over the GT3582R.... the effort is not rewarded. If you need more power the GT4088R seems comparable with the GT3567R in spool, but makes much more power - being a better match and all The GT4088R uses a smaller compressor wheel... http://www.honda-tech.com/zerothread?id=1913532 http://www.honda-tech.com/zerothread?id=1285603&page=1

Sounds suitably crazy. What is the cars setup?

I see, I'd have recognized it if Sweetr33 wasn't calling it a 66mm wheel. The T67 compressor on a GT35 is called by some who do it a GT37R if I remember rightly. That combo DOES provide a bit of an increase on a high flowing/high boost setup. Definitely comes with more lag as well, though I don't know that its very popular. GT4088R definitely sounds like a more sensible way of going about it - though the GT37R is a direct replacement for a GT3582R, nothing has to be changed but the turbo and the tune. Think its something like a 50whp improvement or something? And yeah its for someone pushing their limits.

Strangely enough I thought I'd provided you with enough info to show it'd be a bit premature to look at going a T66 compressor. In my opinion a .82a/r GT3582R is almost overkill for what you are after... and for prosperities sake if you wanted to go "to the next level" a GT4088R in my opinion would be a far better choice than some frankenstein using a god knows how old design compressor.

In my opinion a 260rwkw GTS25t on a set of MickyT ET Streets would rape an 220wkw R32 GTR down the 1/4.