Dyno Chart Full Of Fail - Please Help

[KiwiRS4T]

OK I appreciate your difficulties in getting to the tuner but rest assured cam timing can make 100hp difference in some cases. Tuning is not just about timing. There are half a dozen or more variables and the tuner has to change one at a at a time so that he knows what is making a difference and then change another variable which may affect the first etc. .. hence the many hours involved. If you know a good tuner can you not drive down at 4.30am give him the car for a day (say a Friday) and get him to check the cold start on Saturday morning and then drive home? Whatever it takes it has to be done properly.

[djr81]

Problem being I don't. The last two have been a waste of time and money.

Think I will give the local bloke a go. He is all good, just that there aren't many GT-R's around here and I wanted to short cut the learning process by having someone who has done 100 of them do the job.

Cold start is about the only thing that is fine. So a win there.

[iruvyouskyrine]

Galvsport are the go to guys in WA aren't they?

[djr81]

Did some quick plotting of boost and power curves from past runs with the engine. Anyway this thing looks to be hugely more responsive in the low end - which may very well point at cam timing gone awry.

[SimonR32]

To me your graph in the initial post looks VERY responsive for dash 5's, the boost plots in your latest post seem to confirm this.

Maybe the timing belt has skipped a tooth or 2?

Edited August 3, 2015 by SimonR32

[djr81]

Hope not and hope so at the same time. May just be the cam gear bolts have come loose. Appears to be a bit of a theme lately. Top nut on the drop link on the front sway bar unwound itself and the link fell out of its hole. Hello oversteer.

Anyway cars goes crackle crackle pop pop on the over run.

[Roy]

To me your graph in the initial post looks VERY responsive for dash 5's, the boost plots in your latest post seem to confirm this.

Maybe the timing belt has skipped a tooth or 2?

Who tunes your car? Surely worth a call to Simon's tuner given the reliability and power he has gotten from all his ...um well utilised R32s

[Hadouken]

Go through the effort and take it to a tuner.

[djr81]

Who tunes your car? Surely worth a call to Simon's tuner given the reliability and power he has gotten from all his ...um well utilised R32s

Well Ill ask him on the weekend but it is such a balls ache being messed about by Perth tunas that I am happy given the local bloke a go. He knows his stuff just doesnt get so many 26's. 10 hp aint going to get me near Simons things output plus he has all the gearboxes anyway.

If I can gear near 500 that will be a pretty good result. Working on the assumption the cam timing has shifted since it was tuned.

Edited August 3, 2015 by djr81

[tridentt150v]

256 degree inlet cam, 252 exhaust

Did you mean 262???

[djr81]

No. It is a Poncam A exhaust cam, 252 degrees. Inlet was ordered off their list.

[SimonR32]

Well Ill ask him on the weekend but it is such a balls ache being messed about by Perth tunas that I am happy given the local bloke a go. He knows his stuff just doesnt get so many 26's. 10 hp aint going to get me near Simons things output plus he has all the gearboxes anyway.

If I can gear near 500 that will be a pretty good result. Working on the assumption the cam timing has shifted since it was tuned.

Haha, as of earlier this week I'm back up to 5 spare gearboxes... Was running low after breaking 2 in 2 days

[djr81]

Car ran to 435 (I think) with checked then adjusted cam centres. Will pick it up tomorrow. So wasnt that.

[djr81]

With the boost controller fixed it now makes boost low in the range - so the number at 4000rpm is 270rwhp (With -5's so beat that with a stick) instead of 200. The tuna said it was fairly insensitive to ignition advance and had phased the cams as best he could.

Given the torque output is more useful further up the rev range what would people recommend for bigger cams? It has a 256 degree inlet and 252 degree exhaust.

[KiwiRS4T]

What do you mean bigger cams? You already have very agressive cams. How much lift have you got now? I still think you need a better tuner.

[djr81]

By bigger I mean mostly on the inlet side with maybe 260 or 264 degrees. Boost doesn't tail off so I suspect there is enough exhaust cam in it.

[RB25PWR]

Everyone has already said this but you don't seem to want to do it. Take it to a reputable tuner who knows nissans/rb26's. If you make that $1k a day then f**k me you can afford to take it down to Perth.

A lot of tuning shops offer a car service for $55 a day. Or just go down there early and make a day of it?

Wrong/poor tune can end badly. I drive a lowly old GTST and I won't let the 'local bloke' touch my car!

[r32-25t]

Many people have made that power with smaller turbos and the factory cams, you really need to looking at another area

[Hadouken]

Dont even worry. What's the wortst thats going to happen...

Get 270 cams in that bad boy

[djr81]

Dont even worry. What's the wortst thats going to happen...

Probably a bunch of unhelpful suggestions get posted.

Looked on the rb26 dyno thread there are two -5 poncam posts neither of which have printouts. Thinking my old chart may have been with a stuffed boost controller so cannot gauge the response from personal experience.