Lithium

That is cool I forgot to ask, is your RB25 running upgraded cams? Plenum? And what size fuel system? Gotta set myself up for what to expect hahaha.

Ahh lol, I misinterpreted :-) All good, still awesome to know it is in the making... Which I could do it myself!

Should this have been interpreted to mean that results were going to be posted shortly - or should I start breathing again?

Wow awesome! Is it actually on the dyno as we speak, or in the coming week?? I particularly hope in this case you get good results!

Very very interested to see how that goes! What fuel?

Yep, same findings here too - well except for 900hp on pump fuel, I know a few mad men who have managed 900hp (flywheel estimated at least) on pump gas on RBs. Big turbos, lots of rpm and head porting involved of course. Hahahaha yeah you would REALLY hope it would outspool a T51R, though I would be extremely surprised if you could squeeze the same pump gas numbers out of an engine capable of it from a 6466 as a T51R.... and to be fair, would be interesting to see if the peak power numbers on race fuel would be comparable too. I wonder how those power ratings were determined... Some of these tests make me really wish I had a dyno. A lot of these tests people refuse to touch timing etc to keep things equal, and I honestly haven't done enough first hand dyno tuning with like setups to ascertain whether this is a fair way of comparing or not. Will optimal timing be the same at the same load and rpm for every different turbo setup?

Excellent - that's what I'd hoped, thanks

Scott - did yours only make 228kw?

That's why I thought I'd ask, people have claimed that the PT6262 spools better than the GT3582R which sounds unlikely but who knows. The PT6466 is not far different in measurements to the T04Z and there is no lb/min rating for them - though Precision rate them at 900hp. Does that mean they can be used in place of a T51R Kai on a pump gas setup for someone looking for a bit more power with the same or less lag? It seems unlikely to me.... there isn't even any reason for me to have confidence that they'd make more on pump gas than a T04Z. I'm trying to determine the place of the larger Precision turbos when huge boost and E85 isn't involved.

I thought that might be the case but was hoping some confirmation from someone here might be doable. That is more or less consistent with what I thought, or was hoping to hear. Thanks :-)

Cheers - so was it on a Dyno Dynamics, Dynapack, or some other kind of dyno?

Thats interesting, I'd have hoped for it to be at least as responsive!

So how do people reckon a PT6466 would compare with a Garrett T04Z in overall performance? Would you be able to use the Precision in the Garrett's place and expect to make similar (or better) power on pump gas on a suitably built engine?

What exact turbine was that one? Just a "straight" TD06? And is that on a DD?

Any thoughts on how twin 8cm TD06-20Gs with T25 housings (external) would go on a built 3litre on E85? 550kw @ wheels possible?

In other news, there is an R35 GTR build in the US using twin HTA3794s... That's gonna be interesting.

DAMN you!! Jealous as. I almost traded my R33 on a black EVO 9 GT about 4 years back, and kinda wish I did. I'd hoped they'd depreciate a bit but that didn't happen. The R33 did though

Nice - will be good to see your results One of my mates maxed his GT3586HTA on his RB30/26 (with cams and headwork) at around 25psi if I remember rightly. His fuel system wasn't up to running full E85 so he went with E30 and made 565kw @ wheels with it, hit 500kw by 5000rpm and stayed above that power until the 8000rpm limiter.

Very nice :-) What spec engine do you have? Any what difference have you noticed in spool, fuel usage, or in general so far since going to the HTA?

Need more info...

Hmm - I don't really want to share too much of how I specifically do it as I essentially have my own tuning methods, assumptions, use a dyno that reads a specific way etc and basically you could I'm either (a) too selfish too share or (b) over offering up too much for criticism and having to justify myself. Sorry Here is a site which gives a lot of what you need to work out something similar: http://www.stealth31.../2-calc-idc.htm Bare in mind I never said this kind of method is a definite way of doing it, I only tend to do it when road tuning initially as I don't have a dyno so try and sort out as much as possible so that by the time a car hits a dyno it should HOPEFULLY be as ready to get into the good stuff as possible - I just sometimes use fuel usage (to hit particular AFRs) to determine if everything is working as well as I expect it should be. If fuel usage is substantially up or down over what I'd hope then there is a chance something somewhere isn't doing it's job right - and I loathe getting a car onto a dyno only to find out something is up.

He used to run it on E98 for drags, then changed to an E85 blend using E98 + C16 as a base fuel to mix as he reached the limit of his fuel system. I am not sure if that is still the case, I think he upgraded the fuel system somewhere along the line so whether that was due to more air or to go back to E98 I am not sure. Also don't know if it was normal E70 or 70% eth+C16 for this.

This is very true - not sure how much it would matter in this case, most of the time we aren't running concentrations of air/fuel mix which higher ethanol mixes would show its mettle as much as it might in this case and I've never tuned something at boost levels nearly this high so just speculating really. I'd say results on a car running 8.6:1 and 20psi will have quite different results to one running 10.5:1 and 55psi comparing between BP98, E30, E70 and E85.... knowing that the gains from alcohol between an NA engine and one running boost are hugely different. ie, the difference in gains between going from 98 to E10 and E85 are negligible, while clearly not so much when running a decent helping of boost. To get good NA gains on E85 versus the other fuels you have to run 14-15:1 compression.

For what it's worth when I have done road tuning on cars I've usually been able to get a reasonable guess of what it is going to make on the dyno once timing is sorted just from injector duty cycle etc. It has tended to be fairly relative unless there is some issue, and there is no magic number I have to subtract after calculating it out despite the fuel usage being closest related to engine power while the dyno is obvious wheel hp - so I tend to feel if it isn't exactly percentage loss, that is still the best way of estimating. It is never going to be exact, naturally.

Agreed - amazing stuff on both. Still only E70 too Fairly sure if both turbos were used on their "biggest" options they'd be capable of more, but it seems that Boostin were trying to eliminate anything which the general populace would consider an unfair advantage which I reckon they did a good job of. If I were going full attack with the 3794R I'd probably considered the TiAL 1.03a/r housing, or the 1.32 T4 TS Precision housing. On E85+ the results would be mental too.