Atr43G3 Low Power

[Forgot]

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.

[SargeRX8]

I'll give a reply when I've got a keyboard infront of me!

[Forgot]

Thanks mate, appreciate it!

[dori34]

what fuel pump?

[Hanaldo]

Clutch?

[Forgot]

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.

[Forgot]

Brand new exedy hd button.

[zebra]

Blocked Cat converter?

Shit exhaust?

Shit Intercooler?

Could be any of those

[Forgot]

Blocked Cat converter?

Shit exhaust?

Shit Intercooler?

Could be any of those

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?

[zebra]

how do you know there is no restriction?

did you drop the exhaust and run it?

Valve float is a possibility, but would show up as dips in the power curve.

[Hanaldo]

Speaking of, any chance you could upload the dyno graph??

[Forgot]

how do you know there is no restriction?

did you drop the exhaust and run it?

Valve float is a possibility, but would show up as dips in the power curve.

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.

[zebra]

How healthy is the engine?

Any blow by or anything like that?

Starting to run out of options haha

Cam timing could be out?

But apart from that the turbo is another possibility, if you changed nothing else apart from the turbo that could be it.

Or it could be the tuner?

[Forgot]

How healthy is the engine?

Any blow by or anything like that?

Starting to run out of options haha

Cam timing could be out?

But apart from that the turbo is another possibility, if you changed nothing else apart from the turbo that could be it.

Or it could be the tuner?

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?

[Crans]

Did adding boost add power? Or did it keep falling over?

[Forgot]

Did adding boost add power? Or did it keep falling over?

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.

[zebra]

Just thinking, you havent left a rag or something in the intercooler pipes after changing the turbo.

Sounds dumb but just about everyone has done it.

[Forgot]

Just thinking, you havent left a rag or something in the intercooler pipes after changing the turbo.

Sounds dumb but just about everyone has done it.

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.

[Hanaldo]

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.

Was there knock? Fuel shouldn't affect anything unless you were getting detonation.

Does Sean have any ideas? Has he checked your EGT's and intake temps??

Edited September 22, 2011 by Hanaldo

[urtwhistle]

interesting, let me guess this hyperdrives dyno or ovaboost. forget comparing dyno output's from eastern states dyno's if it is on either of those 2.

My old 34 barely made 290hp on hyperdrives yet cars with the same turbo on the east coast were making 350 or some thing silly and my R34 with a RB3025 running a GT3576 made only 370. I have also seen a r33 on hyperdrive's dyno make about the same as yours with a proper GT3071 so it just reads super low compared to other machines.

So what I would suggest is throw the dyno sheet in the bin and take it down the 1/4 mile. As long as it pulls like 14 yo school boy you should be happy.