Lithium

What about T518Z?

Doh my bad! In that case the closest I know of is a dude who had an R33 GTS25t running a Trust TD05-18G bolt on turbo for an R33, it looked a little laggier than a stock turbo but the car was making around 260rwkw. Seemed similar to a GT-RS, maybe a little less flowing.

LMAO. Apparently a GTR is only a GTR if it runs on a particular kind of fuel?? Bugger - you got ripped off.

For what its worth I'd prefer the Trust TZs over a pair of GT-RSs

The high turbine pressure versus intake pressure at this stage could possibly be largely due to the fact that the inlet pressure is disappearing after the intercooler?? Going by his pressure measurements as far as the turbo is concerned its running 2.4bar of boost - it just so happens the boost is not making it all the way into the engine. For it to have pumped itself up to 2.4bar it'd have to have developed sufficient turbine pressure for it to reach the shaft speeds necessary to do that, which would be why you are still running high exhaust manifold pressures. I would probably try and drop the boost level while trying to resolve where the boost is going so you don't blow a turbo trying, as whereever the pressure is going is not doing anything any good! Though how far did you drop the cam duration?? Does the car idle high or do you have any lean miss condition going on? I suppose if its still running an aggressive cam it would be hard to identify this kind of thing.

I hate boost leaks A tool which could pump "smoke" through the system post intercooler would be very handy at this stage to see if or where it came out. One then we did when I had a leak with mine was squirt compressed air at different points of the outside of the piping etc while the car was idling and at least in my case you could hear the engine react to the higher available airflow. I assume you have ruled out any chance of the blow off valve or a join in the piping leaking? Good luck with this, this sounds like it will end up completely insane when done - how far did you go with the twin GT30R setup?

Roy - I didn't mean outright VE, I meant maintaining a good VE up into the higher revs... the engines VE changes throughout the rev range, peak VE in my understanding should be where peak torque is and then it drops. If you want to have an engine which CAN rev to 9000rpm a large amount of the focus will have be be put on making sure the head is going to support the flow at those revs. Both RB20s and RB25s are dropping off hugely by then. And I understand what you mean by dribbling on, I am a big fan of it - its what keeps these forums going and conversations like this can end up in really interesting things happening. Or shitfights haha No worries Seeing as it sounds like you have perused the dyno threads, where are the RB20s falling over? I know people who have spun RB25s to over 8000rpm, even on hydraulic lifter heads - 8500rpm is the highest I know of but I'm not 100% sure on all the supporting mods done. I know a lot of it was pretty typical, forged pistons (lower than stock compression, ~8.6:1 but thats just for high boost friendliness), rods, balance all the bottom end stuff, get an oil pump which can handle the revs and generally make sure you are always going to have enough oil in the right places. Get it all balanced!! And you will have to run a decent exhaust and inlet manifold as well, a nice high mount manifold can actually help them wake up in the high end quite nicely once you've got some decent cams etc. I'd probably swing towards going a Neo solid lifter head if I were to try something like that myself, though I've been in RB25s running 8200rpm and I tell you - with a GT3582R bolted on the side and a decent set of cams they feel a LOT angrier than what you'd associate with the power delivery on an RB25 running a stock turbo or even a GT-RS. And that brings me to the next bit, how much boost/power are you aiming to run? I think GT-RSs are struggling to flow enough air efficiently at the high end of the rev range of a stock revving RB25DET, much less an RB of that displacement area which wants to rev to 8500rpm or so. You are going to need a turbo with a reasonable amount of compressor to not choke the engine on its mission up there, you can probably forget any GT28 or potentially even GT30 based turbo - and unfortunately as a result of that also forget any chance of making full boost under 3500rpm. This kind of stuff is why we rarely get to have the best of both worlds

OK you are talking about RB20 blocks - in the case of an RB20 block, it comes with a head which takes reasonable work just to match a stock RB25 head in terms of flow, but alas you can do work to the RB25 head to take that further too. As much as your bottom end is able to rev is no good if it doesn't have good VE up there. In terms of what the topic is about, the block thickness (which I am unaware of anyone not shooting near 1000hp having issues with anyway...) "issue" will apply to this guy anyway given he is using the RB25 block. Unless he is specifically on a mission to build a motor to rev as high as possible without any concern for performance etc then seriously man, 2mm of difference in stroke is not going to be noticeable on a decently built motor. Food for thought - Hondas F20C (S2000 motor) which has a stock rev cut of around 9200rpm and generally makes a RB20DE feel like a joke in terms of willingness to rev and has a almost RB30ish stroke of 84mm, go figure.

Its an interesting idea, and its always interesting to see something different but seeing as you are asking for an honest opinion I am going to be predictable and say I think its a ridiculous idea. I have no idea why people think that RB20s rev better because they need to rev - being torqueless doesn't mean they are better up high. Yes it has a SLIGHTLY shorter stroke, but the same as an RB25 has a slightly shorter stroke than an RB26 - no one complains about how they rev. To be honest, do the same work on a true RB25DET (people will just call it a destroked RB25 anyway) and get all the revs plus the bigger displacement - you get the best of both worlds. If you do the same work to an RB25DET and your hybrid, then drive two cars with the different setups - one will make more torque than the other... and a little more power. Thats all that will stand out. My opinion, save your money - its going to be an aweful lot of money with the only positive at the end being the ability to say you have something a little different.

The cam profile thing comes up again - a couple of us answered this on GTRUK forum and there was no answer, hard to feel motivated to add more if you don't know if the person is reading or considering the suggestions.

Fantastic, thanks for sharing Sounds like an awesome piece of kit - I bet its fun! Good work.

Gah stupid rolling road dynos having no rpm indication or solid link to hubs so it can all be put on an even scale for comparison. Very impressive curve shape though, care to share specs??

I am guessing you guys are talking about Oz records? There is a 120Y over there which has damn near done 10s isn't there?

I only said MAYBE, and remember I was referring to using a stock RB25 head. I agree with the point you are making, however my rev comment comes from the fact that when you use a STOCK RB25DE head on a larger displacement engine, NATURALLY you are giving the 3litre a head which will flow exactly the same on a flow bench as the 2.5 litre.... giving it (per cubic inch) a more lazy power curve. Put the equivalent flowing head on a smaller motor, the smaller motor will turn into a "make my torque at higher rev" motor - put it on a bigger motor and it goes the other way around, one of the reasons RB30DETs using stock RB25 heads come across so chunky. The 2JZGTE comes with a head from stock designed to be on a 3litre, so its a little different and even then people straight away shove a set of 264s or bigger in when going for more power - which is what anyone building an RB30DET *should* do if they aren't just clowning around.

Both in the territory of 360-370wkw on Dynapack hub dynos on just pump gas. The one running 130mph which hasn't done a ten yet is in an R32 GTSt running a .82a/r GT3582R, the one which HAS done a ten was in a GTS4 and had a small shot of nitrous to help it along additional to the ~370kw it ran on 22psi through a Turbonetics T66. It did 11.1 without nitrous. Funnily enough there is an RB25DET powered R32 GTSt here in NZ running only forged pistons, completely stock head but a shot of NOS and a GT3582R which has done several flat tens. So far the stock head RB25DETs here are faster than the stock RB25 head RB30DETs here, maybe due to not having a slightly compressed rev range?

Yes I have been in a few RB30 powered cars actually, one of which is a proven 10s car and another one (given its 130mph trap speeds) is only a matter of time before it does a ten. Can you explain what "all other cases" means?? All motorsport in a Skyline should be done above 4000rpm, and the R33 I refer to had plenty below 4000rpm to not feel compromised at all for normal street duties - it reaches full boost (22psi) by 4300rpm. Its a proven full interior 10s car and runs on pump gas. The RB30s were reaching their peak power at low 6000rpm while the RB25 I refer to at well over 7000rpm and actually on the road felt angrier/faster overall than the RB30s I've been in. Virtually all the RB30DETs I've been in are your typical stock RB25 head, stock RB30 bottom end, 22psi type setups. The 10s RB25 has a REALLLY solid push in the back from just over 4000rpm carrying through to 8000rpm as opposed to just under 4000rpm to 7000rpm for the RB30DETs. Bare in mind I have already said the RB30DET is in my opinion the better motor, I am just sticking up for the RB25DET in the light that people are possibly selling them a little short. The RIPS car I was talking about was the blue one, not the black one - http://drag-r.com/gallery5.htm

Have you ever been in/driven an R33 with that kind of power or its just a conclusion?? I have been in a 400kw R33 GTS25t running a .82a/r GT3582R and it was really quite streetable, it didn't have V8 style urgent below 3500rpm but it wasn't a gets-beaten-by-Fiestas-from-lights type car by any stretch either. If you stayed heavy on the gas over 3500rpm in 1st/2nd/3rd gear it would not take long at all for the tires to get completely baked, surely the only difference with a RB30 would be a couple tenths of a second earlier before the tires start baking?

Nice power, though that air fuel ratio is definitely what I would call scary lean - especially for that boost level. Also, you seem to have a bit of boost creep, not terrible but.

Yep thats basically it for me, I am still umming and ahhing about what I want to do with mine. In terms of outright performance, a 3litre is it - end of story. There is no replacement for displacement, and given that you use the same head as the 2.5 or 2.6 you are at no loss. The 3litre has the nearest to perfect rod/stroke ratio out of the bunch if I remember rightly and there is no reason without balancing and a decent strength bottom end, and a decent head that they shouldn't be able to rev HARD. I know people spinning them to well over 8000rpm, and making really really good power with them. Hell there was an R34 GTR built here in NZ with a forged RB30 bottom end which runs >1000hp and up to around 8500rpm - probably has the widest/fattest power delivery out of any street Skyline I have seen. I like the idea of having something like that but on the flipside SOOO many people have RB30DETs, and in NZ at least there is no love for the 25s so it'd be nice just to build an RB25 and have and enjoy a powerful streetable one which you KNOW is good. If nothing else, for the sake of staying pure to what the car was is a good reason to stick with the RB25.

Absolutely, I can see that - ditto with being not a Garrett fanboy... but I like to have the advantages pointed out to me why turbo xxx is better than turbo yyy when it has been stated that way but there is no obvious proof. For what its worth, your dyno plot for 340kw @ wheels looked HEAPS like a mate of mines running a .82a/r GT3582R on his RB26DETT with very similar mods. He ran 371wkw on a Dynapack hub dyno running 20psi in a GTR with pretty similar spool. Definitely sounds like the Blitz beasty is a decent unit. And on average from results I've seen (and I always run on Dynapacks so making my kw smaller isn't really in my ego's interest) Dynapacks read about 10% lower than Dyno Dynamics, though it seems there are the odd DD dynos that read quite high - there are always exceptions to the rules depending on who has set it up etc.

Very nice, looks like fun - how much boost is it running to do that? Something I'm not too sure about however is that last comment - especially performing anywhere near as good? Can you elaborate please, I certainly can't see anything on that dyno plot which shows it having anything over a GT3582R - what I see on that plot is a car making GT3076R power with GT3582R lag. At this stage I have not met anyone who have had reliability issues with a GT3582R yet and have various mates using them for circuit racing at quite high boost levels, making much more power than what you have posted in this thread... and if you have had a Garrett BB failure because of contamination it wouldn't be the turbo I'd be criticising. At this stage it looks like you can buy a 6boost manifold and a GT3582R for the same price as just a K5-660R by itself, so I am at a loss for what the advantage is? Please bare with me, you must expect being questioned if you are going to make such statements - the Blitz/KKK turbos are definitely a minority amongst the tuner turbos so if someone comes up with one on their car, and makes wild claims about performance it definitely makes one want to know more about it Cheers.

DOH I was a bit slow on editing it, I was just talking about boost level in general. No, not on a GT30R - there's probably no point going over 22psi on your setup... sounds like just the right level

Ahh yeah sounds like a good idea, on both levels 22psi is pretty much where I'd be going high boost as well. 20-22psi is high but really a safe limit for pump gas, so long as you have a good tuner etc - I know people running way more than that, but they are certifiable. Really looking forward to seeing the results on 20-22psi, it should go very very well.

NICE! Been keeping a real eye on this thread, will help me decide on whether to keep the GT30R/RB25 combination How hard are you going to push the tune when you do it? It'd be rude not to crack the 20psi mark!