Lithium

My first ride in a Skyline that I can remember was in an automatic R32 GTS4 a few years ago. My impression? Highly disappointed. I couldn't believe it was a turbocharged 6cyl that was (trying) to push it. Handled well though, and nice to drive on the open road. Sounded nice too I haven't really got over my grudge for RB20DET GTS4s since either.... I had been in a lot of pretty modified V8s etc at this time though, and had high expectation based on what I had seen GT-Rs doing, and also from hooning around in a 300hp turbo Commodore :headspin:

No bad, only 2 weeks behind us!

The old 4AGZE is actually a really good motor, ports are good sized for boost induced power - the bottom end is very very strong, and the ECU and injectors are reasonable overrated for stock. Get a supercharged one, a semi decent intercooler, a turbo (EVO TD05's work real well I've heard) and an aftermarket ECU and you'd get a light car without the hassle of an engine transplant etc and over 300hp. I know plenty of people who have done it, with excellent results.. I also know a guy with an AW11 MR2 ( the early shape I assume you are talking about) with a 3SGTE from a late model 2l turbo MR2, it is happily a 12s car. Anyway, this is a Nissan orientated forum so I should shut up now

That might be because its either not out in Oz yet, or just because no one has seen it there yet :headspin: Considering I think the first 4 standard out OK, then got progressively shite - HO4 being the best quality utter shit I have ever seen - I think I am pretty neutral. High Octane Overboost is definately worth a watch. Don't ever watch HO4.

Yeah, this one is maybe 10% crap - which is still more than I'd like, but its better than the previous one with the trip to the US which was pretty much 99.9% crap. High Octane 4 is the 2nd worst car video I have seen (Max Power - Beasts From the East being the worst) and High Octane Overboost is the best...

What mods do you have? If its relatively stock I'd try an ECU + dyno tune and a lighter flywheel.

One time I had a flatmate go out on the booze for a night, and left his car keys at home - we wired his horn to the left and right indicators.. had him quite confused for a while :headspin: Do you live with smartarses? Thats the closest to that problem I have seen, sorry :Oops:

Thanks I am not sure what a "good launch" is rated as being with a GTS25t, but I run 255" tires on it and don't get much more than scuffing - just enough for it to not bog. 60ft times (based on the GTimers reporting) range from 2.05-2.09s for the 4s runs.

GTechs can read "optimistically" if not mounted firm against the windscreen, as they can lean back and as a result read higher gforce. 4.7s is dead on what a mate of mine was getting in his near stock R32 GT-R on mine, had 3" exhaust at the time. My R33 GTS25t does reliable 4.9s on a Passport GTimer with 211rwkw.

Sig: 14.1@ 101mph~ Pegasus (stock) While I am picking nits then, does my car count as stock? As mine has the same mods as yours had when you ran the 14.1 :Bang:

To be honest, not 100% sure - I just figured if you had leaky injectors o- then it would still be possible for the ECU to not pick up on any problem , as the ECU will be looking for anomolies in voltage or anything like that. Essentially, the injectors could be working as far as the electronic side - as with the ignition etc, but if the fuel is either pouring into the cylinder - or alternatively pouring around randomly then maybe that could be causing problems!? Do you smell any fuel smells around the engine bay or anything? Just throwing ideas around Sorry if they are a waste of time...

How on earth can 107.6mph = 109mph?? Especially when 13.68 equals 13.6? A Talk about optimism

Were the injectors tested before installation?

I agree completely, hence the fact that I am quoting my 14.1 @ 103mph time on my sig as my cars performance - despite the fact the car has a lot more power than it had when I did that time, as until winter ends there is no chance to prove its new potential Anyone who knows me will know that I don't like to give myself false hopes, that time was just used to get an indication of progress and I posted it because it was an interesting comparative result. Out of interest, the used road surface IS actually quite difficult to launch on (and there is the whole fact that being winter, its not going to be a nice sticky surface) - the launch method was virtually driving off from stationary and giving it gas when it was rolling (basically a 2000-2500rpm slip then floor it) which still resulted in some spin (despite quite good 255s)... but was easier to control from lower revs etc. 2.05 60ft indicates a very good launch, but because of the nature of the technique I wasn't carrying as much speed at the end of the 60ft as from slightly higher revs

I just had a bit of a test run on a friend Passport G-Timer to see what to expect roughly with my new mods, since running a 14.1 with catback and pod. I now have a cold air box with HKS filter, 3" catback exhaust, S-AFC2 and bleed valve with the car dyno tuned to run 11psi - running stock suspension and 255" rear tires. With the boost set to 10psi (don't entirely trust the bleed valve since I found it gets boost spikes on the road) the more notable results were: 0-60mph - 4.93 0-100mph - 12.05 0-60ft - 2.05 330ft - 5.78 1/8th - 8.78 @ 83.2mph 1000ft- 11.33 1/4 - 13.47 @ 105.3mph Run was done with mechanically sympathetic gearchanges, I think there would be a bit more in it

Nice! Let me know how it goes, I'll wait with interest Zahos: Just do what I do, wait for somebody elses misfortune and vulture them when they just want to biff the turbo :headspin:

Yeah, I know about that way around it - but I would rather not

Haha - I'd love to One of my friends blew his R32 RB20DET turbo recently, running ~18psi through it :headspin: This is how I am getting one so FREE, I just happened to think of it when I was pondering how to alter my boost actuation. How long have you been running 13psi through your stock turbo??? Thats pretty up there...

Hiya all If you've seen the "Pushing a mostly stock R33" you'd know where this question comes from. Anyway, I have an R33 Spec2 and would like to run ~2psi more boost and hold it properly. At the moment I have a GFB bleed valve controlling the boost level, but it bleeds off quite quickly after peak boost is reached - though I know that the Rb20DET turbos seem to run a couple psi higher boost than the RB25DET ones, so theoretically if I used the same boost control they do I should get similar boost behaviour - so wouldn't really need to rely on a bleed valve. I can get an R32 RB20DET turbo for free, does anyone know if I can use the actuator/actuator spring with the RB25DET turbo? Any thing I should know? Cheers in advance! Dan.

Yep, definately - the S-AFC2 has a knock readout, and I tend to mess around with settings on the dyno

Well, seein as you are running 13psi (so probably drop to 10-11psi) - quite a bit from 4500rpm (where they seem to peak) up to 7000rpm based on the boost plots I got for my car. I should really scan them and post them. From memory 1psi (slightly less even) boost at ~6700rpm gained me ~10rwkw at that point. I got 202rwkw on 9psi, with 9psi coming at ~4500rpm and dropping to ~8.5 at peak power - and got 211rwkw peaking at 11psi @ 4500rpm, dropping to ~9.5 at peak power. Of course mid range still gets some pretty decent gains

Thanks for the input guys It looks to me to be pretty much what I expected (seeing that people with FMICs and dp/fps have the problem too) which is that the factory wastegate is behind most of the problem, so I am guessing that an external (or replacement internal) wastegate would improve it a lot - though an AVC-R would probably do quite a good job of tricking it into holding boost as well. Might have to nick a wastegate actuator from someones broken RB20DET turbo and experiment - we'll see

Good point - that would be quite a good idea, though where is the "13.5" magic number defined? What pressure drop is it assuming etc? Shame its not feasible to attach a tacho to the turbo hehe Most people talking about 13.5 as measured at the plenum afaik. I am just after 11psi (or even slightly less) right through the rev range, I'd just like more "area beneath the curve" - and think that up-and-down boost running isn't the best way about it.

Hi all! I am trying to improve the all around performance of my Spec2 R33 GTS25t while maintaining acceptable reliability, and not spending huge amounts of money or having the car being obviously fairly modified. At the moment it has a 3" catback exhaust, Pod filter with cold air box (and ducting), removed charcoal canister a GFB bleed valve and an S-AFC2 which has been dyno tuned to run at 11psi, which I don't want to go past with the stock intercooler and turbo. The thing I have noticed, that when looking at the boost plot from the dyno tuning - it reaches 10.5psi quite quickly (2400rpm), creeps out to a peak of 11.3psi (momentarily) at 4500rpm and by the time it reaches its peak power at 6600rpm the boost has dropped back off to about 9.5psi - where peak power is attained. The "base" dyno run I did for some reason peaked out at 13.6psi, and dropped back to a minimum of 11.5psi - interestingly enough that was before it had a bleed valve installed!? Anyway - what I conclude from this, is that the factory wastegate is not much fun - and is obviously opening earlier than I want to, stopping the car from reaching 11psi straight away - but then after it reaches that peak it stays more open than it needs to be and the boost is dropping off, as opposed to the turbo running out of efficient flow. The most obvious sign that the car wants to push harder, is briefly as the boost is dropping - it levels off from its decline at around 10psi for a few hundred rpm between 6000 and 6500rpm and there is a corresponding increase in steepness of the power curve until the boost starts dropping again, where the power curve returns to being almost flattened off completely. What I am thinking about doing, is installing an Apexi AVC-R and getting that tweaked to allow it to hit 11psi straight away (ie, ~2500rpm) and hold that until the end - in an effort to increase torque, and also keep the power curve climbing at the steady rate it appears to want to - possibly gaining me near 10kw @ wheels peak power, but most importantly having it so its not dropping boost in my "working area" of 4500rpm -> 7000rpm. Question is, I hear the factory intercooler has quite a significant "pressure drop" across it - due to inefficiency more than cooling effect, and I don't want the poor stocky to be revving its nuts off to supply 11psi at high engine rpm through a restrictive intake system. Will this be a dangerous amount to push the turbo? Any experiences with Apexi AVC-Rs and boost behaviour using them? Any help would be very appreciated Dyno plot from the final tune at 11psi for reference should be attached:

The RB25DET turbos have a ceramic-type exhaust wheel, and as far as I understand at high speeds/temps they can break off and head off for more carnage - so its not just efficiency thats not going to be ideal. But on efficiency, as far as I understand a turbo's efficiency is measured on turbine rpm vs. air type scale - so maybe an RB25DET demands in the same area of turbine rpm from the turbine for 12psi as an SR20DET does to be pressurised to 17psi, being a bigger motor and all.