Lithium

Ran into electrical gremlins on the dyno - it's a freshly built race car, and it was a bit of a rush to get it on the dyno. It made 500awkw (rolling road) on 24psi running E85 with more in it, but I doubt that will happen too soon.... I'll naturally update when anything else happens

And an interesting update since the boost creep issue has been pretty much sorted, couldn't do 3rd gear because of lack of traction (??!!!!) on 18psi - even 4th getting a bit skatey (it's around 0 degrees here tonight)... decent spool even on 80% throttle though:

Pretty sure they use the same T04S compressor cover

Or you could get ridiculous and get the RB26 crank and put it into an RB30 block and get some custom 132.8mm rods made up to generate a stock stroke RB26 with a 1.8:1 rod/stroke ratio to take the edge off some of the loads and maybe reduce piston acceleration at TDC a bit - little things that can potentially help make a revvy engine reliable and efficient. As it stands stock stroke RB30s have a better rod/stroke ratio for higher rpm etc than an RB26, but higher average piston speeds due to the stroke length - getting a more agro r/s ratio using the RB26 crank in an RB30 but keeping the same avg piston speed could potentially put valuable movements towards making an effective revvy RB.

And how much time would it spend on that 11,000rpm limiter in a year? This guy has mentioned it being used in a drift car....

A lot of the time they don't realise they are part of that group... With all due respect people who are able to and inclined to provide useful input are going to struggle to reconcile with supporting the direction you are talking about in good conscience. You have decided what you want, and seem best to go to a workshop who will be much happier about taking money than asking questions and throw money at them. Let us know how it goes!

You do nothing but skids so it's EXACTLY what you need!!

Probably not a setup most people would go for on RB25s, a HTA3582 will make more than enough for what most people would need in a RWD - so I'd not hold my breath for that one haha. A mate's GTR (RB30/26) is going on the dyno with his HTA3586 tomorrow on E85 so I'll update on how that goes.

Pretty sure everyone who had commented are well aware of the 25G, and we haven't been given any detail beyond the engine needing to make good power up to 9000rpm. Not that I have checked compressor maps but I know a mildly hotted up RB25 can run to choke on a 25G within more or less stock rpm range and not huge boost so going up to 9000rpm on any kind of boost level is a tall ask. T78, ewww haha

9500rpm is really really working the motor hard - hope you have a really good block and are not worried about breaking things, its a really counter intuitive way of building things... especially if you want to run it as a track car. You say you don't want to make lots of power etc, but at the end of the day you need a dyno/drag -queen spec head if you want a turbocharged engine holding power to 9000rpm. The reason being is to maintain good enough volumetric efficiency for power to hold at those rpm you will effectively be redesigning ports, going silly cams and doing fun things with the combustion chambers - and all the supporting stuff to keep the valves being actuated they need to be etc. If you are holding VE at those rpm then hp per psi will be higher than if you were only spinning to 8000rpm, so if you ran it at the typical 20-24psi people tend to with a build motor you will make a lot of power. Well unless you run a 25G compressor, in which case it will try and spin itself to bits trying to maintain that boost at that flow level and pump all sorts of disgustingly hot air etc. If you are spending the money to make this kind of thing happen and are not after big power then you're probably going to be sensible to consider a MUCH better turbocharger than the 25G and a nice big hotside on it - you should be able to afford it if you are aiming at racing an RB which spends a reasonable amount of time in the 9000rpm range. I'd be looking seriously into the likes of an EFR8374 turbo which has a pretty broad range of efficiency, good turbine flow, good response etc - with something like that and VERY good electronic boost control you should be able to build something with a strong midrange and then bleed boost backwards through the rev range, ie 24psi from 5000-6000rpm and then bleed back to 1bar at 9000rpm... something to hold the engine's flow requirements below the choke line of the compressor, and give you a more or less flat power curve (torque dropping for most of the rpm range). You WILL need to go a decent crank trigger setup, amongst other not cheap things...

Nah, but there are a couple around on RBs already and they work well

That was easy, hahahaha

Nope, if each gate cracks at around .5bar then you just have 38mm x2 opening at .5bar - I would be surprised if they could hold that turbo at .5bar though

I think that clip is confirmation that the twin HTAs are actually an awesome thing, especially if you are looking for an upgrade or alternative to GTRS/-10s. Looking forward to seeing how it goes on the dyno

Success - strangely it holds ~.9-1bar of boost on wastegate boost, which is more like what we expected in the first place. Mysterious, but at least it's sorted now

FYI here is a clip showing how an RB26 with low mount HTA2868s drives :

If it does, then it's a shame we won't have a final dyno plot for it - be fun to see how it goes though

Didn't measure but it would have been 20-something mm across, a reasonable amount taken out - hopefully it helps... maybe? Will find out Saturday.

Want to buy one? I may have one here :-P I don't rate them on RB20s, or in general - now you can get TD05s from Kinugawa in T3 flange you can get comparable spool and way better power brand new for a reasonable price

Probably not. At the end of the day the best way of knowing is Stao getting some of these things on cars and seeing how they perform in general, and over time - if they are an overall success then a win for everyone

I see, the TD05 sounds promising in this case. The high PR capable 16G6 will suit the application even more Because we have no other great ideas the waste gate port has been opened up some and we'll give it a road test this weekend to see if it helps with the creep

Agreed largely, though carbon buildup over time is one of the big issues VNT systems often have

Agreed, so far (will confirm when we identify the cause of the boost creep) it seems like a good thing - basically it was settled on due to the fact it should flow more than enough for a stock SR20 between 10-20psi (and we had 250+kw DIN as a target on E85), and offer good response and generally nice driveability as this will be used for track and gymkhana type events - and it seems like it is very well suited so far. Sounds pretty cool, too- haha

Sorry I thought I had mentioned, we actually held the swing arm open to full swing to test it as well - so eliminated the actuator itself, though dump pipe etc need to come off to investigate further. At this stage I can see no reason why the Kinugawa unit itself should be blamed, as again it held boost fine for a while and the actuator at the very least is not the cause... at least that I can see. In terms of the mapping, sounds like you have the gist of what happened now anyway - but for what it's worth I don't go for full MBT with tuning, at least on cars like this which all of their kms are hard, especially on a completely unopened motor on a track car... so that 250kw (or 241kw SAE2004) is a REAL number, where I wanted the tune to be... not one I leaned on to show off. We were going to do a 20psi power run so he could have lols at drags and show off what it'd do on 20psi, but that also would have been with a "as it drives off" state of tune - as people may figure (definitely those who know me will know) I am all about making the engine happy, and being excited when I find out the number is good.... as opposed to obsessing about the number itself. There may have been more kw in there for the taking if someone wanted to push it, but imho not enough to justify the extra strain. For what it's worth, here is the compressor map for the 16G6 compressor: Fwiw I use lb/min = CFM / 14.4718, so by 1bar of boost you are looking at around 40lb/min of flow - it'd make >190rwkw pretty happily on the right setup even without running a lot of boost however on 1.8bar it gets up to ~43lb/min of flow which is pretty decent going - if anything it's going to make that power on pump gas happily, and with headroom. What engine would you be running on the rally car? The design has obviously been used on 2litre AWD 4cyl rally cars for AGES now so obviously a fairly known combo, it feels very usable on the SR20 imho though each to their own. It isn't as jumpy as the old PE1420, you can feel response time - but it is really good for the power you can get from it and the cost, imho. Here is a snippet from that road test where the car is rolling around a corner at part throttle in 2nd and then feed into it - I know it looks like the boost climb is laggy when you glance at it (as with the rpm), I zoomed in to the point that the time splits are small enough to give an impression of what is happening when.... this is with 10hz logging too, so things will look more progressive than they really were due to interpolation by PCLink software to pretty the graphs. I'll let your draw your own conclusions from it, but again when seeing 16psi by 4500rpm it's worth noting that .3s earlier the driver was at half throttle/3800rpm/6psi and it took .2s from that point to hit full WOT

Sorry, didn't print the boost plot - however I have a boost plot from the last logged road test it had before the dyno (nothing had changed aside from timing between this test and the dyno, and the creep was still there when timing came back in) so will attach those. Here is a screen shot from the log from the last road test before the dyno - this was using Link boost control to hold 19psi to make sure we could, to prove we had boost control (ironically... bastard thing): And this is with Link boost control turned off on the dyno, so just wastegate boost: And in case you wonder, we did try bringing on boost control to see if having it run more boost low down will somehow use strange fluid dynamic properties to combat creep and no- it seemed that no matter what it wanted to creep above 5000rpm, we could just control how much. It also would hold 10-12psi on the road previously... but now it doesn't. Currently exploring the possibility that something in the dump pipe is blocking flow. What do you mean by the softer timing map? I had tuned the car entirely on the road (funnily enough) and it has been running for a good year+ on that tune until now.... I used a mixture of educated guesses and input from VirtualDyno/KnockBlock to make sure things seemed reasonably within territory for that tune. I dialled timing back around 7 degrees (depending on where in the map) just before putting it on the dyno so I was likely to be able to find gains by adding timing instead of having to go back and forth. As it turned out I was usually within 2degrees, if not literally bang on the timing I decided on with the dyno tune - which is nice. I was not knock limited on ethanol at all, it would have definitely gone over 270kw with more timing - and also more rpm, we just had no intention of running it to that boost level. The car is running a china stainless stock location manifold and an internally gated T25 flanged antisurge 3" inlet TD05-16G6 8cm unit