whatsisname

Hey mate. Shaun always leaves it set on road speed for some reason. He did tell me why at one stage but I can't recall. It is laggier than the HTA3586. No big surprise there, given the 0.85 vs 1.01 housing change and 62mm v 67mm comp wheel. Running the numbers through a basic speed to RPM calculator (using gear ratio [4th = 1.000], differential ratio [4.111], tyre diameter [641mm or 25.24"], and vehicle speed) it shows that 10km/h equates to roughly 300-400RPM. HTA peak torque arrives at approximately 120km/h which is just over 4000rpm in 4th RS peak torque arrives at approximately 130km/h which is just over 4350rpm(4377rpm) in 4th 80km/h is near enough to 2700rpm 90km/h - 3000rpm 100km/h - 3400rpm 110km/h - 3700rpm (112km/h is a smidge over 3800) The RS overtakes the HTA by approximately 4200rpm. I've got 7800rpm to play with. I'm picking it up this afternoon, so I'll report back later tonight or over the weekend. The plan is to hit the strip once the TC/LC system is sorted - had to send the system back to the UK for reconfiguration and bench testing. The graphs really don't do either turbo justice. Response with the HTA was exceptional. There was no big ramp up onto boost, it just spooled up and by 2500-3000rpm it was turning the tyres. I'm fine with a shift to the right by 350-400rpm, it means speed will be up and it should be less likely to want to swap ends. On the street I don't really care. As long as it can keep up with the traffic I'm happy. I'm old enough to know I don't have to prove anything to anyone. The car is too 'pretty' to see any serious track use. The drag strip is where it will be unleashed in full. However, I'm not aiming for any records, it's just a hobby and a bit of fun.

Posted in the RB30 results thread but figure it probably should go in here given the back story resides here. As per the plan, we added 1psi in the mid range, bringing it up to 27psi. It drops off to 26psi at peak power. Added a touch more timing up top as well. HTA GT3586R 0.85 vs GTX3584RS 1.01 350-400rpm drop in response vs. near on 70kW peak gain and reasonable gains from 4200rpm upwards. Roughly 870Nm at 4500rpm. 335Nm at 3000rpm. As a comparison, a mate's VE SS with supercharger running 6psi, mild cam and usual intake and exhaust mod's made 375kW and 660Nm peak the night before mine on the same dyno.

Did the rocker issue occur on the same pass as the 136mph trap? Must have had issues on that pass surely, as the trap speed seems a bit on the low side for a relatively light chassis, especially considering how responsive it is. Obvious spread of torque and peak torque is a major factor but with over 450kW at the wheels I would've thought it would be well into 140+ territory.

Worked on the boost control set-up, added 1psi in the mid range, and a bit more (1-2degrees) timing up top. Dyno overlay isn't 100% accurate but it's close enough Results:

The interesting thing is that neither of those torque figures seem to match the factory quoted peak torque figure of 295Nm + a modest increase given the obvious increase in power above standard. A standard R33 GTS25t 5sp manual RB25DET produces say roughly 130-140ish kW at the wheels on a roller dyno, based on my experience. So that's a mild increase of 25-35kW. The 256Nm reading is well down on the factory claim and even more so for a 25-35kW increase. The opposite seems likely with the 418Nm figure. It is quite high at 123Nm increase, which doesn't seem to correlate with the mild 25-35kW increase. In short, neither torque reading seems to line up with a mildly modified RB25DET. Then again, perhaps a 25-35kW gain does correlate to a 123Nm gain. I know my Golf GTI Pirelli produced 212kW at the wheels and 422Nm on a Mainline roller dyno. The quoted power/torque for APR Stage 2+ was 250kW and about 450Nm. Pretty close to the figures recorded on the dyno when taking drive train loss into account. I guess at the end of the day the actual figure is less important than the before and after results.

I don't dislike derived torque as such. My comment was aimed at clearing up any potential confusion from people seeing the torque figures I stated and thinking they're not very impressive for the set-up (RB30 HTA GT3586 etc) The dyno I use gives torque figures that compare to the original torque ratings from factory. So 295Nm from a standard R33 GTS25t vs 860Nm from my RB30DET vs. 628Nm from the new HSV GTS-R W1 My old built RB25DET produced 366kW at the wheels on a Mainline dyno and 1023Nm, which doesn't relate to the original factory figure of 295Nm in any way, shape or form. Clearly it was not making 1023Nm vs. 295Nm of the standard engine. It probably had about 550-600Nm. Obviously if one sticks to the same dyno, Mainline in this case, then at least each subsequent dyno run after the baseline is directly comparable and as long as the torque figure increases across the bulk of the useable RPM range all is good. Yes I have read the Mainline dyno article.

The 0.85 rear housing was maxed out. Probably a bit more in it with the larger 1.03, 1.06 rear - with the obvious trade off in response. Response was very impressive. 325Nm at 2800 600ish at 3500 850ish at 4200 Genuine torque figures not derived torque.

It produced enough torque to start spinning the 265 A050s at about 2500rpm. It was very responsive on the road.

Dyno of my old HTA GT3586R 0.85 set-up, to save on searching through the RB30 dyno results thread.

My RB2530 was running a HTA GT3586R with the FP 0.85 rear. Best we got out of it was 463.7kW at the wheels on 25psi (dyno sheet is in the RB30 results thread) More boost and more timing made no difference to power. Mild non-Neo head, HKS cams, 3.5" exhaust. A 1.01 or 1.06 will be required to reach 500kW. Response was outstanding with the 0.85, will obviously lose a bit with the 1.01/1.06. I decided to switch to the new Gen2 GTX3584RS with 1.01

The 3.2 might be running high compression which would help it make decent power even at relatively mild boost. My makes over 525kW at 26psi - RB2530 10:1 not running an EFR though.

Shaun is snowed under with work at the moment so unfortunately for me it's hurry up and wait. Going to ramp boost on harder and add 1-2psi in the mid range but stick to 26psi up top.

R33, built RB2630, GTX3584RS 1.01 making 548.9kW at the hubs and has ran 9.6 @ 145.97mph Not sure how much boost nor response etc. Auto too so probably 560-570kW through a 5sp manual https://m.youtube.com/watch?v=HtwR2p9XZcw

Got a set of Nankang NS-2R in 120TW for my daily driver - RS Megane Cup. $155ea fitted for 235/40/18. Dry grip: 8/10 - noticeably better than RS3, KU36 etc Wet: 7/10 Value: 8/10 Wear: Unknown at this stage but expect at least 6-12mths of daily use. 2-3 sets for the price of say one set of MPSSs. They're noisy but not unbearably so.

Can't wait to see what you've got in the pipeline mate. I've got a picture of the alt bracket fitted. I'll see if I can find it. Will send one through tomorrow morning.

Hey Tim. Mate it has been a while! I often wondered what happened and if all was okay. Glad to see you've come out the other side. I genuinely hope life is treating you better now you're back. I will shoot you another email (same as back in Aug) and we can pick up where we left off. Awesome to see my custom alternator bracket pic up there [emoji4] Looks perfect with the red inlay! Cheers, Matt

As soon as I get a chance I'll get Shaun to overlay the two runs. It's laggier, as I expected. Plus it isn't coming on as hard with the current boost control and w/gate set-up.

I am obviously biased but I reckon it sounds okay too: https://www.youtube.com/watch?v=flKPG36nLdw

There are literally no other engine changes from when it had the 3586. Same everything bar a switch from T3 flange to v-band flange on the exhaust manifold - but same manifold. Same dump, same intake etc. It is as close to a back-to-back as we could get. I'm guessing hotside.

Thanks mate. No problem at all, always happy to share my experiences, good or bad. I am confident we can improve the boost curve to get it coming on harder and therefore area under the curve. Some further info from the dyno session on Wednesday evening; Shaun spent the first 10mins adjusting base pressure and checking the fuel mixtures, as we'd switched from a Sard FPR to new TS FPR1200. Once A/FRs were optimised he did a power run. 421kW at 10psi creeping to 19-20psi. After a quick change of wastegate line configuration and boost control adjustments the second run produced 463kW at about 24psi. At about this point I started getting concerned it wasn't going to produce the goods! The next run, with boost set at 25psi, resulted in 488.6kW. Shaun could obviously see the early signs of disappointment starting to show on my face and said to me 'don't give up on me yet mate!' accompanied by a grin. The next run, it made 499.2kW. The gains were all coming from adding timing. GTX3584RS was continuing to make gains where the old FP GT3586R had nosed over at 25-26psi and extra boost and timing simply didn't make any extra power. Run after run it kept climbing, 503.3, 507.7, 513.X, 525.3kW I am confident it would keep making gains with additional boost provided the engine doesn't hit a restriction somewhere. 560-580kW at 30-32psi would be my guess. 600 is a possibility with a decent head/cams set-up and everything else optimised and set to kill. Down the track at some stage I will get to find out.

I'll check and get back to you mate

True, although this way there's potential for gains down the track. I'm hopeful we can improve response. Yet to drive it as there's still a few things to do.

Cheers mate. Yeah made the power I was hoping it would. That was my stuff up, I forgot to ask Shaun to switch it across to RPM. We are yet to switch to the 4-port Mac valve so hopefully further improvement in response to come. Shaun strongly suggested we leave it at 26psi for reliability and longevity. I wasn't going to argue with my engine builder and tuner. The same guy who will look after me if something goes wrong.. provided I follow his advice

GTX3584RS 1.01 26psi Max of 7800rpm There is more in it but decided to leave it there for reliability and longevity. I have no doubt 30-32psi would deliver 560-570kW, possibly more. Made 421kW at about 19psi - lazy curve whilst setting up boost control, so 10psi slowly creeping up to 19ish

Max of 26psi boost and revving to 7800rpm