Lithium

They have Andre Simon (tuner/proprietor of Speedtech motorsport and driver of the worlds fastest EVO - DOCILE) on board tuning the car now. The team is continuing development over winter, and it sounds like they might make a mission over to Oz to have a go at Jamboree later this year. You should look forward to seeing the fastest time done by a GTR done on Australian soil if that happens They are running "somewhere over 1300hp @ wheels" now...

Using NOS like that Z has sortof makes it not an NA accomplishment, unfortunately. Also, the thread is specifically about straight 6s - not saying they are better.

Still no word on Oz's answer to this? I don't doubt something will emerge at some point... but the bar is being raised. Heat Treatments ran at Meremere with a new turbo setup this weekend (a single LARGE turbo) and did a 7.81 @ 177mph with traction issues, so wouldn't be surprised if this drops with fine tuning.

I have been under the impression the plastic wheel is slightly larger - but on the down side, if it ends up "over spinning" the tips can flex out - and clip the housing.. then snap!

My bad - sorry for putting you wrong on that I had assumed that the only Prelude that anyone would bother turbo'ing would be one with an H22A in it. B20As are pretty poos. I've got a couple of mates with stock engine'd Hondas (one a 1.8VTEC Integra, the other a 1.6VTEC Civic) both running 8.7psi (.6bar is a nice safeish boost level for a stock VTEC motor) and both do mid/low 13s quite happily and reliably.

WTF - I didn't bother signing up, but he's clearly doing something seriously wrong. One of my mates have a forged H22A and large turbo on his Prelude and did a run on 6psi (only tuned for engine run in) and managed a very wheelspinny 13.2 @ 186kph. With 11psi and a built motor (built motor is an advantage as on NA the tune is usually just to keep it alive) an H22A should be making some pretty decent power. They are at least comparable to an RB25DE in NA form, so the same would suit for when a turbo is attached to a built RB25DET.

Hey Geoff - thanks again for the blat, I've always wanted to see what an RB30DE felt like... I love the effect having the motor balanced has had on the old RB30E bottom end Sounded very nice as well, particularly the induction noise. Going in the car you can tell the motor would like to make a bit more grunt with some tuning. FYI though - that dyno graph doesn't show your car running rich down low, it shows you running lean... then dropping down to a safer but still a bit lean air fuel ratio. So yeah, if you get an S-AFC - if you're going to make any adjustments before putting it on the dyno... bump up your fuelling down low.

BADR33 - Yeah, I am from Wellington (aka Lith on SkylinesDownunder).. I've met you before - I think I was driving Dan from MIDAS's R32, but now my R33 GTS25t is running I'm usually seen driving that. I'm guessing if the car is running by Thursday I could be seeing it in the Hutt Anyway, good going on sticking to NA with the car - I think its cool, and it should go pretty good all going well. Definately something a bit different!

Hehehe - Don't make assumptions In the 90s there were a few RB30DE VL Commodores and R31 GXEs running around with them - even in the Hutt Valley no less!! There was a street machine article in the late 90s detailing how to convert the RB30E -> RB30DE using the RB25DE head, and it captured quite a few peoples imaginations. I have been quietly watching your build and am very much looking forward to hearing how it goes when it hits the dyno - and your on-road impressions. I've quite fancied the concept for a while now and have never actually checked one out close up Shame about the weight of the 4 door R33.... could make quite a sleeper hehehe!!

Not quite completely off topic - how does the GT3071R drive on the car?? Does it spool ok??

The Speedtech EVO (aka DOCILE) ran an 8.23 @ 179.5mph this weekend here in NZ, I'm waiting to see if there are any videos circulating of that run - if so I will link it up. The fastest run I am aware of being caught on camera so far of his is an 8.35 @ 174mph run that was done a couple of weekends ago: http://www.pizzaboy.orcon.net.nz/dragvids/docile_835.wmv

The current (in NZ at least) issue of New Zealand Performance Car Magazine has a write up on the car, and the time.... and the fact that it has a fair bit more in it

I'm not aware of any videos of that run yet I've been waiting for one to show up. I know it was with a 1.42s 60ft, so theres more in it - the car has run quicker 60fts. Heat Treatments have run another 7.9 since this post, not sure what trap speed - and GDS (Glen Suckling) have run in the 8.0-8.1s, but not quite cracked into the 7s. The NZ 4 and Rotary nationals are this weekend coming, I suspect there might be some more news after then

The man himself said he didn't get into top gear - they don't have a reputation of talking shit (maybe this is common in Oz???).... 256kph trap speed when they usually run 270+ is an obvious sign. Apparently they are working on what went wrong with the box with the intent of running tomorrow. I guess that will clear some stuff up?? They've already done an 8.033 @ 172mph already - so no matter what way you look at it, a solid seven second pass is inevitable... if not now, with the new motor.

WTF is that supposed to mean?

Any more happening in the GTR-700 camp? I've been keeping an eye on the website and all has been quiet since July. Reece McGregor ran an 8.03 @ 172mph in NZ this weekend just passed, and backed it up with an 8.09 - 7s should be happening really soon. I can see GTR-700 as the only GTR between him and HKS GTR at the moment...

Yeah - I wasn't 100% sure on that one, I thought the 250wkw cars were possibly running the VG30 turbine housing. There is definate varience between dynos though, is this reading done on a dyno which reads consistant with other ones which have run 250wkw? I know this could sound stupid - but were any runs tried at lower boost - such as the 1.3bar mentioned by paul? Maybe exhaust gas temperatures are becoming insane at 1.4bar, the thing might even be able able to match the power level on a slightly lower boost level? Do you have a decent dump pipe? What kind of intake/intercooler system are you using? Is there any chance that there could be an air leak somewhere?

Wouldn't the tiny R33 turbine housing (~.48a/r) end up creating HUGE amounts of back pressure, and resultantly heat when the exhaust gases from an RB25 breathing 19-20psi of boost at high revs is trying to force its way through? I would just not try to run that kind of power through the RB25 turbine housing.... I wouldn't be surprised if swapping to a VG30 one would make the world of difference.

Thought this would be a good place to make an update - Heat Treatments ran at Masterton Motorplex in NZ this weekend and set his PB, and then reset it again: First run was an 8.33, the second run was an 8.28 @ 167mph. Congrats Reece and the Heat Treatments team

Awesome! Cheers for the information, me and some friends have been discussing the T04Z lately. I was just today trying to find out if anyone anywhere had compressor maps for them - partly because the most recent HPI to hit NZ shores (GTR-Special) had an R32 GT-R with twin T04Zs on it.... what a fascinating combination!! In light of what you say about it compared to a GT2530 - it'd be interesting to compare compressor maps, if the "shape" were similar. I had noticed that someone had compared the boost threshold with twin GT2530s...

Thats interesting - I always thought of boost as a measurement of restriction? If you get higher lift cams (and get the ECU tuned for the change) - won't the engine be able to allow more air in at the same boost level?

Well - if it was my car, the first thing I would be looking at would be the intercooler piping. If its fine off boost, but starting running rough and not boosting when you'd normally hit boost - it implies the turbo is sucking air in through the air flow meter, so while the tune might not be perfect it would suffice as the car is more or less running naturally aspirated. When the turbo has reached the point its sucking in enough air to make boost, the engine will still be drawing in atmospheric pressure and will start overfuelling and retarding. I hope this is the problem, as it will just be a pain in the arse

Roy - I'd misread the full boost thing.... though he did say 14psi by 4000rpm, which is pretty decent spool, no? This is bearing in mind that RB20DETs don't spool turbos overly well, and need a few revs to go - I'd imagine (as Quincy said...) that one should go very nicely on an RB25DET. Mafia - Do you know if there were any modifications to the VG30 wastegate port to allow it to hold boost like that? Are you using a Garrett supplied actuator with it?

Quincy777: How do you find this on the road? What kind of dyno, and at what boost level was that power made? Like the baby-T51R whistles?

Now that we know someone has made 250kw @ wheels with a GT3071R on an RB20DET (other thread) with full boost by 4000rpm, we can agree that the GT3071R is a good unit? I have a VG30DET housing, this can be machined out to fit the GT30 turbine wheel happily enough - and the GT3071R comes with a .5a/r TO4E compressor housing.... shouldn't this combination be able to fit down low easier than the GT30R low mount described in that other thread, and provide some awesome performance for an RB25DET? It sounds like the GT3071R-WG (w/ cut down turbine) was a good combo for the RB20DET.