Lithium

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.

kw only tell part of the story - even R32 GTRs are a LOT heavier than the 25t, so that effects power/weight and the fact that the engines are similar size means there is a huge difference in the effective power delivery. I am running pretty much the same turbo on my 25 as Cubes is and I haven't been in a GTR running stock twins that pulls as hard as my 25t does.

Nice results cubes So peak power arrived on 6000rpm? Man, look forward to seeing how mine comes out when I can allow it to rev out cleanly. Sounds like lots of fun to drive haha. Hope the wavey curve isn't anything major, does your boost curve waver to match? Yep those cams ARE tiny. Port sizes on the R32 head aren't great either... car would still be a beast on the road but has plenty left in it.

My little 2c worth, what I thought long and hard about when I decided what parts I was going to use was actually "What to I want the thing to drive like?" instead of "How much power on the dyno do I want?" etc. For ME after driving lots of different cars etc, I decided that having a little bit less down low is far from a bad thing with a R33 - having full boost at 2500rpm makes for quite a boring drive, fellow RB25 owners are probably well used to RB20 owners raving about how their cars are more fun to drive because of the more aggressive power delivery. I also found it annoying having positive pressure cruising up the gentlest of inclines, so a bit more lag was a good thing. The 56T still has positive pressure by 2000rpm, and by 3000rpm its giving a decisive push in the back even though it takes until about 4000rpm before its turned into Hyde. I've never been in something RB20 powered that gives as much acceleration at 3000rpm as I get with mine, and the owners of those cars are perfectly happy with what they own. Its not a dig at RB20s, its just using the fact that the "What is acceptable lag" is a relative term. I guess what I am saying is, there are factory performance cars with much less meat down low to a 56T GT3076R which are running similar redlines - maybe people have based their perception on whats a good turbo for an R33 too much on the fact that they come from factory with a shockingly undersized unit? I really really reckon that the 56T made the car SOOO much nicer to drive, even when not giving it a bootfull and haven't had anyone drive it and think otherwise (or at least tell me haha). The best way of working out what you'll actually enjoy - this is especially worth considering if you have never actually been in a 300kw @ wheels car, is going in someones car with a similar setup to what you'd consider and make sure the way it behaves how you like. For some, a GT2530 which whacks you HARD from the start and falls over early in the rev range might be their idea of fun - while for others a .82a/r GT3582R which is OKAYYYY up until 4000rpm, where it decides its time for to meet your maker - and won't stop trying to send you there until near 8000rpm. The problem is looking at numbers on paper won't really tell you, you really need to experience it. You may find that looking at dyno sheets, lag looks like you have a compromise - while on the road when your driving it its more of a lull before the storm.

ARGH what is it with people here and complete intolerance to dyno's which read higher than your notoriously low reading dynos? If it reads higher than yours, it isn't WRONG - same if it reads lower. Its just DIFFERENT. Look around the world, making >400whp on pump gas has been done only plenty of DSMs and SR20s around the world. People have made in the region of 500whp with GT3076Rs, and GT3582Rs are often considered as near 600whp capable. We all know you shouldn't expect that on a Dyno Dynamics - the reason for this isn't that they are happy dynos or that yours are sad, its just that they are different. If you need a right or wrong, then majority rules would say that the Dyno Dynamics ones are the ones which are wrong because to some degree it appears that results on the net from Dynapack and Dynojet out number DD. Its just a tuning tool.

Yeah that definitely doesn't seem normal, when mine was near stock (just exhaust and filter) I had a meet where I ended up lined up with a manual TT 300ZX with the same mods and I beat him MARGAINLY each run. However, if I had a front mount, ecu and tune I'd like to think I would have completely trounced him

Haha what normal person really wants a 200+awkw car? I suspect the new GTR will have enough power to embarrass lightly tuned RB powered GT-Rs, given the fact that it sounds like it will have 3.5litres +, will probably have variable valve timing + lift (VTEC ftw haha), and a pair of turbos using modern technology. It'd be HARD to have it a fun car to drive (ie, not choke above 5500rpm) and NOT make in the territory of 500hp with that efficient a setup.

AWESOME to hear, sounds like its going to go VERY fast...

I hear this ran a 8.7 this weekend and looks like it has plenty to improve on.... congrats John and keep it up

Ahh ok I was just making sure that was clear And in no way am I implying that running more boost would make it more responsive! I was just making sure that it was clear that a big/plain bearing turbo won't be giving anything away to a small BB turbo in fatness of power delivery once its at the same boost level. It'll obviously take a bit longer to get there....

The reason your power delivery is so much fatter for most of the graph is you are running 18psi......

I don't think there is anything to clear up. Keep going to the same dyno and you can compare your own progress with yourself. If you want to see how fast it is - you race it. There is varience between most dynos anyway, so there is no point measuring using someone elses stick... because there is always going to be someone who says the reading is "wrong".

But you can enter whatever you want into the calculator

Fair point - gotcha. I think people say rwkw as a matter of habit Moroso is a calculator based on estimations and assumptions. A dyno is far more direct... an engine dyno is the only thing that tells you how much a motor makes. The drag strip is the only thing that tells you how fast it is down the 1/4 Most people these days are savvy enough not to claim their car is quicker (or not) based on whatever the dyno spat out. Otherwise I'd probably be pretty keen to get on the lowest reading dyno anywhere and take the credit for being a better driver than everyone else haha

It is a hub dyno - as has been covered. He's clearly making >250rwkw, if he was making 200-210rwkw thats what the readout would have said. Its all relative, the dyno is a tuning tool etc etc etc. So, on that dyno - realistically he is making 250rwkw. Dyno Dynamics is somewhat of a minority in terms of the dyno results I've seen around the world, only contended by Mustang dynos in terms of low reading - so I don't think you can really say his reading is wrong Dynapack hub dynos and Dynojet rollers seem to have some degree of parity between them.

Good to see how the Masterpower turbo behaves. The reason for the high reading is Dynapack hub dynos read higher than the world famously low reading Dyno Dynamics dynos. Dynojef and Dynapack dynos (which outnumber the Dyno Dynamics which are rarely used out of Oz) read ~10-15% higher on average it seems. I made 274rwkw @ 15psi at only 6000rpm before we stopped the tune on my R33 on Speedtech's hub dyno... power was climbing steeply there. I run a GT3076R with a stock RB25 with Nismo 555cc injectors, and walbro pump.

Yeah thats why I said I was breaking from the habit - hardly anyone has actually posted their own cars. I could have posted some awesome ones of other peoples.... but anyone can find a random clip on you tube.

To break the trend a bit, this is actually my car - problem is the external drowns out the turbo's spool a lot in that clip, have been working through a boost creep issue so the wastegate is venting to atmo until have got that sorted (its actually got a new manifold going on it at the moment). http://www.youtube.com/watch?v=ClXcNtAMJjg

I'd go with a GT4088R for that power level Better spool than the T04Z, better flow than the GT3540R.... somewhere in between/closer to the T04Z in power potential.