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I'll EFT someone $50 if they can solve my issue as it's doing my head in

The engine has been rebuilt by a reputably builder and tuned by a well known workshop. I have no issues with the engine builder or tuner, happy with both just want to find a solution

Car:

R34 GT-T

Hypergear 3582 Tubo

3inch Tbe exhaust

Return flow intercooler

New 460 l/h Walbro fuel pump

Bosch Ev14 ID 1000 injectors

Nistune

Rebuilt engine

Standard fuel rail and regulator

Issue & comments by the tuner:

  • Car hits a brick wall when making power. It hit 280rwkw on my old ss2 turbo and now about 315rwkw on a bigger turbo.
  • Engine cannot take timing up top. about 10 degrees less than normal on 98 and 8 degrees less timing on e85 compared to a normal setup/
  • It made 315rwkw at 4,500rpm on e85. And 310rwkw on 98 octane before the tuner didn't want to push it anymore due to safety concerns
  • Engine is healthy and no noise
  • It feels like his tunning the car on a really low octane fuel
  • Spark plugs 3 & 4 did look a little hot and a slightly different colour

Diagnoses:

  • Tried tunning the car on e85, made the car more responsive but still hit the brick wall
  • Injectors have been flow tested and are ok
  • Exhaust dropped on the dyno and no restriction found
  • Cam timing checked and spot on
  • Compression test done and 175psi across all cylinders
  • Compression ratio on the engine checked at 9.1:1

Background:

  • Car was fine running 280rwkw on an ss2 turbo
  • Car was stolen and engine blew up as the guy who stole it ran 91 octane on a hot day
  • Block warped and car got so hot the coil packs literally melted
  • Engine rebuild (forged + ported) from a new low km's auto neo block+ new Brae manifold. Manifold and exhaust heat coated
  • Car went on the dyno on the old setup and when it hit 280rwkw and not making anymore power it was thought that the turbo was too small causing back pressure. Car could not take timing up top. So changed the turbo.

Idea's solutions?

Maybe something else was damaged in the engine bay when the car got really hot when stolen or?

Thanks :cheers:

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I would be checking out the cas signal to make sure it is ok, and probably replacing it to rule it out. If there is a lot of noise coming from the cas out will screw around with the ecu. Also inspect closely and maybe replace the cas loom, to ensure a clean signal

  • Engine rebuild (forged + ported) from a new low km's auto neo block+ new Brae manifold. Manifold and exhaust heat coated

Factory Exhaust manifold and internal gate?

If so 300rwkws has always been about the limit using a factory exhaust manifold

equal length pipes.

pretty sure its internal gate

I would be checking out the cas signal to make sure it is ok, and probably replacing it to rule it out. If there is a lot of noise coming from the cas out will screw around with the ecu. Also inspect closely and maybe replace the cas loom, to ensure a clean signal

Will check this out

Ahh missed that bit.

What size rear housing on the turdbro? are you 100% sure the exhaust ports match the runners on the exhaust, is the inlet cam solenoid working as it should

Stao said it was a direct copy of a the Ford xr6t 3582 turbo. Pretty sure its a 0.82 rear housing.

Also pretty sure the exhaust ports match the runners

No idea if the inlet cam is working as it should :/

What is the boost doing? Is the boost dropping off when it hits this brick wall, or does it hold pretty steady?

I don't have a dyno graph printout. But boost was holding pretty steady @22psi till it was backed off

The car wants to make power. The power curve gets kind of vertical before stuff happens, not happening when its flattening off or anything.

You can kind of see the dyno graph in the background pic

1016452_629246753806662_1236021066_n.jpg

Checked fuel pressure with a flow gauge? Pump getting 14v ?

Checking fuel pressure did cross my mind

Scotty did my pump and its new. I had an old Walbro in there on a previous dyno run and the issue was still there, so don't think its the pump

New Walbro 460L e85 pump, hardwired to constant battery voltage through a relay. AFR's were fine...

Too quick!

Scotty was also there when the tune was done. So he can also throw in his 2 cents on reply's

Noticed in the pic on the dyno your running the factory air box. Have you tried bolting a pod on to eliminate that as the cause?

I know GTR airbox's are good for 350kw, but comparing a GTR to a GTT airbox, the snorkel on the GTT has a big squashed section in it to clear one of the 'cooler pipes and the area around the inlet to the AFM is quite tight.

I'd run it up without the airbox connected or chuck a generic pod on there to rule out the airbox. The turbo might be working really hard to suck the air through and heating up the intake temp

Head been skimmed? block too? any other cylinder head work? Also a stupid question but the cam lobes aren't worn down are they? Do you have stock valvesprings or HD units?

Edited by Super Drager

Noticed in the pic on the dyno your running the factory air box. Have you tried bolting a pod on to eliminate that as the cause?

I know GTR airbox's are good for 350kw, but comparing a GTR to a GTT airbox, the snorkel on the GTT has a big squashed section in it to clear one of the 'cooler pipes and the area around the inlet to the AFM is quite tight.

I'd run it up without the airbox connected or chuck a generic pod on there to rule out the airbox. The turbo might be working really hard to suck the air through and heating up the intake temp

Im not sure that the stock airbox is an issue, Yeah GTR's boxed have an extra side feed for theirs

I think people have pushed lots of of power through it?

If the tuner thought it was an issue im sure he would have just taken it off for a quick dyno run?

FYI it also has one of Scotty's 3 inch metal air intake

Head been skimmed? block too? any other cylinder head work? Also a stupid question but the cam lobes aren't worn down are they? Do you have stock valvesprings or HD units?

Head 'skimmed' and block too. Bored and Honed + 5mm

Valve springs were aftermarket performance springs and are 85lbs on the seat

Head ported and polished. Camshafts not worn, we had the rocker covers off shortly after it was running

So to summarize - It won't take timing, but WILL hold boost but refuses to take timing as the revs climb? Does it take less timing the higher the RPM it's getting? Is it simply not making power because feeding the appropriate amount of timing into it will result in ping city?



How much power does 8-10 degrees of timing get you anyway?


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