Robo

Yes, same rear housing and both were IWG at the time. To be honest, I may have had too much back pressure which was apparent when moving to the 8474. But I will never know (I don't log back pressure). I will say I expected more from the 9174 with such a large rear housing and twin EWG. We shall see what happens after the next round.

I just looked up the dyno graph comparison, it was about 100rpm of lag difference (9174 had more lag). Both setups are always tuned the same way as in boost is as aggressive as possible. Power curve was almost identical until 5,000rpm where the 9174 started making more power all the way to redline (70whp more on a mainline). I am still running a 3" downpipe though (with exhaust cut out) and will be upgrading to 4" downpipe with cut out plus S3 cams soon. I found a fellow in the US with same car who also went from 8474 to 9174 (small Ar to large Ar) and he told me he barely lost spool and made more power up top (this isthe reason I made the change - it's true), I guess the 1.45 A/R is a very well engineered housing.

I went from a 7163 to 8374 to 8474 to 9174 and I am glad I did, it's an incredible turbo with amazing spool. My car is not a Skyline sorry, it's an EVO X with sleeved and built 2.16cc engine (plazmaman IC, direct port meth injection, S2 cams, sequential 6 speed etc) 8474 was twinscroll IWG and only 0.8 A/R rear 9174 was twinscroll EWG with 1.45 A/R rear The 8474 came onto boost way too hard and made it undrivable (like between 3.5k to 4.5k was vertical on the dyno). The 9174 we all thought being so much bigger rear housing would be lag city but surprisingly it was about the same as the 8474 (we only changed the turbo and nothing else). I see 1.5bar (22psi) by 4,300rpm. I am not done yet, I'm increasing the downpipe and going to S3 cams (Time attack car). Rob

Thanks for the heads up, This one is double layered and has been on there for over 4 years now, will inform the workshop. Rob

Hey there, I had exactly 2.0bar, it was completely flat all the way across the upper rpm range. This peak was at 8,500rpm where we stopped the run. in other news, I have just finished my side cutout in downpipe:

Thanks for the replies, Yes I never thought of the IWG plumbed into DP causing the flow issues. Either way, I will install a cutout valve in my Downpipe so It should solve the flow issues. Was thinking otherwise I have to go 4" exhaust like GTSoy said. Geoff, yeah you guys have been great through my build (also ran a 7163). I am concerned about running EWG as both space and heat are an issue for me. This is a dedicated track car (more time attack) now and only at Sepang F1 Circuit which sees 52 degrees °C track temp.. I have seen a few EWG struggle with heat due to placement in Evo X. I would much prefer an exhaust cut out in downpipe over twin EWG setup. for my IWG I have never had an issue holding boost flat up top. I recently changed to the 4 port boost control and twin port IWG turbosmart unit (which got me the 2bar @ 3,90rpm in 4th gear) and holds flat to 8000rpm. to be fair I have slightly different gear ratios to a stock EVO (sequential 6 speed) Shooting for 650whp (on a mainline) with the next round of tuning. Rob

This is a great thread, After reading a huge chunk, I have a question for all those high hp setups running 8373 and up. What exhaust are you all running on these Skylines? Reason I ask is because I ran into flow issues on my little track built EVO X running 8374 (IWG) with a 3.5" straight through race exhaust, we removed it and ran with downpipe only and made 30whp gain at only 1.6bar boost. I can only imagine how much more power you can make with a side plant (exhaust cutout operated with a valve). I'm installing one now... I was looking to upgrade my 8374 to a 9180 but now thinking after reading this I'll go to a 8474, my setup is sleeved block 2.2ltr (4 cyl obviously) with direct port meth injection, sequential 6 speed, head work, oversized valves and makes over 600awhp on a mainline dyno (I flew the boys from Powertune over to tune it). peak power is 8500rpm and I get 2 bar of boost by 3,900rpm in 4th gear. Car weighs 1280kg after stripping it (with roll cage) and being built for Sepang F1 circuit.

Yeah going very well!! Tax is fantastic over here, only one problem for me..... I miss cars soooooooooooooo much!! haha good to see you are doing research before jumping into things.. Will pm you from ozaudi about a couple of things When I bought it I only had like 45k's on it (but that was many years ago now).. Talk soon Rob

Hey Heysey, Sorry - old post but want to say congrats! I too went from a Skyline (R33 gts-t ser2) to an Audi S4 Done any more mods yet?? I got a little carried away with mine.. Was just about to upgrade turbos but instead had to move overseas for work and thus sell!! I'm sure you have done a fair bit of research but to give you a better indication.. With just a chip (Giac tho) and cat back exhaust (which almost went the whole way up the car) managed a 13.003 and 1.8s 60ft (first time out to WSID, heavy 19's and a seriously slipping clutch!) Power wise was more like 250 kw's - running 1.55 bar of boost too (would hit 1.55 by about 2250 rpm) Things you must change - Throttle body boot, BOV's (get rid of the plastic stockies) and you will prob go through a couple of AFM's even with the stock airbox.. Some recommendations: - C/O's, Sway bars and semi slicks make the thing stick like s%$t to a blanket!!! - Go Giac chip... - Get a manual boost control (to smoothen boost from fluctuating) - Go exhaust from turbo back (lots of work involved tho) - Upgrading turbos is the way to go (but expect about 10k+ and then some) - Upgrade you I/C's to RS4 units.. Much better flow and much better cooling If you haven't spoken to Nils (Milka) on the audi forum already.. I suggest you do.. The amount of times I went to his place for help on little things haha Some pics: Ohh one more thing.. I very highly recommend upgrading the centre diff to the Stassis centre diff (for the S4) it sends about 20% more power to the rears and helps a huge amount on reducing understeer and more oversteer - which is needed on this car!!! Rob

I had my AFR's tuned to 11.8 with my Power Fc (R33 gts-t with tbe, pfc, fmic, pod etc..) Before that it was more like 10's.. Cheers Rob Ps. Could it be the fuel pump on it's last legs? (justa thought)

Could the ECU be re-programed? What boost was it running on the dyno?

Hi all, - Near new Defi BF gauge with control unit 2 for $350 - Oil air seperator with blue silicon hoses (fits R33 gts-t) unit can be sealed or left open. $150 Please pm or e-mail me [email protected]

Hi All, Tried searching but could not find anything. I'm interested to know how an R34 GTR would compare to an EVO 9 around a track (e.g. Wakefield). Talking stock power and susspension in both cars. I assume the Evo would be in favour here but by how much?? Thanks Rob

Hey Kris, haha.. Shame I don't get to see your ride every day I really like it.. a lot.... Tell me when you go to the track/wsid next, I'd love to come along.. Rob

haha Can't remember now.. But I was driving the same car as u I'm thinking of going to Oran/Wakefield next, want to test my semi-slicks out.. I don't go to WSID often, infact it's the 2nd time I have been there. Talk soon Rob Ps. Let me know how u go