Forgot

Well I might chat to Sean & see if he remembers how he tuned yours, there has to be something I'm overlooking. Will try a few things when it's on the dyno tomorrow.

Did you change anything between Andy's tune & Seans or was it just the tune itself that made the difference? I really don't think my tune is the problem, Sean is a gun tuner & I have 100% faith in his skills.

Jesus, they're almost identical!! Hanaldo, I don't suppose you have a dyno graph from your tune at allstar do you? Might be pretty interesting to compare. I just can't help but think that I'm missing something, even if you disregard the actual power figures there is a BIG difference in the shape of the graphs between SimonR32 & my graphs & almost every other graph I have seen for these turbos.

One thing I did find last night was that the 2-2.5" silicone elbow I used to join the compressor outlet to the cooler pipe has a slight kink in it, like it has been bent slightly past 90 degrees. Now its not a big kink BUT at higher boost levels, could this cause enough restriction to effect spool of the turbo & hence effect the top end?

Here's my dyno graph for those interested.

I definately agree, I don't think its the turbo either. I might get a test pipe made up to replace the cat just in case that is the issue & I will test the intercooler as well to see if there are any restrictions.

Actually Stao, you are probably most qualified to comment on this but what do you make of my & SimonR32's power delivery? It seems that both of us made pretty good power through the midrange but didn't make much more at all from then onwards. Most dyno graphs I have seen that are using your turbos seem to make good power right the way through to redline (ecept in cases where boost control is an issue). I will post up my graph tonight but it is quite similar to the one SimonR32 posted.

Well its good to compare to someone who's been on the same dyno with a pretty similar turbo. I'll have a chat to Sean & see what we can come up with , maybe thats all she's got.

Seems like you are having similar problems, what does your tuner think about your situation? My intake is definately not a restriction though as mine is simply a 3" 45 degree bend with the Z32 & pod filter attached to the end. As far as how it FEELS, well it feels like it has 320rwhp. If it felt like it was making the appropriate power then I wouldn't care what boost I was running but it just doesn't, even if you take into consideration the variance between the east & west coast dyno figures, its definately lacking for some reason. I hope you manage to sort your issues out as well! Can be frustrating sometimes.

Well that almost rules out the turbo if it's preformance has been proven. I will try another run without the exhaust & see what happens.

Will try to post up tonight.

Thats what has me concerned, the fact that it seems as if its choking up top. If it continued to make power from 4500 then im guessing mid to high 300rwhp wouldn't be out of the question. I have a 3" stainless intake so no restriction there.

Full boost @ around 4200

Yeah, Sean is a mate which is why I take it there but I have no doubt that Andy is a more than capable tuner! I will post the graph as soon as I get home tonight cos I do realise its hard without that. You guys have given me a few things to check anyway & if there's nothing wrong then I'll just drive it & be happy with the results. It could well be that my motor is just a bit shy on power full stop, I was really just concerned that it wouldn't take the extra boost. Also Hanaldo, looking at your results on the same dyno & a smaller turbo it just seems a little strange that I am getting a fair bit less.

Nah it was on Allstar's hub dyno. Im not so worried about the number, it just doesn't feel like its producing what its capable of thats all. I mean the stock turbo made 255rwhp on the same dyno with mostly the same setup (except for Z32 & injectors) so I was expecting around the 350 mark. Like I said though, there's every possibility that there is nothing wrong & this is as good as it's going to get, I just want to make sure theres nothing wrong for safety's sake.

I had planned on going E42 anyway (not just to solve this problem) but it wasn't knock related, just wouldn't make any more power so Sean left it at 16psi. He didn't really have any ideas & thinks it might just be all the turbo's got in it, which could be completely true but after seeing so many people consistantly make high 300wrhp it's making me wonder.

Hahaha I don't think so, BUT I don't know 100% The tuner had the cooler pipes off as well because it kept popping them off so its definately a possibility.... Might explain why its a little more laggy than I thought it would be I will check tonight but I'm pretty certain that isn't the issue.

No, it didn't make any more power at all. The midrange improved but the top end just kept falling over, which to me sounds like a restriction somewhere. We are going to re tune on the weekend with E42 (mix of E85 & 98) to see how it responds to that but it should be making a lot more power already.

Tuner reckons the engine is pretty healthy, there was a slight film of oil in the cooler pipe but there is bugger all blow by really. As for timing, to be honest I haven't checked but I would have thought the tuner would have picked that up? Maybe not. I wouldn't think its the tuner tho, he's one of the best in Perth & has tuned both SimonR32 & Hanaldo's cars with similar (although smaller) hypergear turbo's with impressive results. In saying that though, I'm not ruling anything out at the moment. Of course logically the turbo could be the culprit but seems strange that it would make 300hp fairly easily & then just stop making power?

Yeah we did drop the exhaust & test. Well there are no dips in the curve, the curve looks pretty good (albeit a little laggy) its just down on out put. I will post up the dyno sheet when I get home tonight.

Yeah I did think about those, but the exhaust & cat are in good condition & there are no restrictions there but I haven't tested the intercooler. It is a HKS cooler but I guess its possible that here could be something wrong. Aslo, could it be a valve train issue, ie valve float causing a boost leak?

Brand new exedy hd button.

Sorry guys, just realised I missed a few things! Turbo is Atr43g3 .84 (with.6 front not .7) profec b boost controller new walbro fuel pump.

Thanks mate, appreciate it!

Hi guys, I just got my car tuned with Atr43g3 and it didn't make as much power as I was hoping, infact compared to most other results it's a fair way off. The car made 320rwhp @ 16psi, now the problem is that when the tuner pushed more than 16 psi it would gain midrange power but the top end would drop off. As it stands it made 300rwhp @ around 4500 rmp & only gained an extra 20 hp over the rest of the rev range which suggests that there may be something wrong. The specs are: Rb25det (130000kms) front mount intercooler Full 3" exhaust 3" metal intake 850cc injectors Z32 afm Brand new oem coil packs Power FC Now this car made 255 rwhp with the stock turbo @ 11psi & I would have thought that this turbo would have easily pushed 350-360wrhp (260+rwkw) So does anyone have any ideas? Also, those figures were on a hub dyno.