That's impressive. That guy can do even better. IMO, his tune is not aggressive enough.

What cams was he running? From the TQ curve, I have to think NA, no?

 

I wrote this on the train:

"First off, you are limiting yourself top-end, which is fine. I understand that this is not a race-car. So, know that you are not set-up for maximum top-end, but for optimum.

My guesstimate is that your NA cams also rob you roughly 10% at the top-end. How? I have to think that, knowing your cam configuration, the tuner would have had to tune conservatively. I would have. Better that way than blowing a hole in the block and bad-mouthing me.

To get top-hp, regardless of driveability, you need IMO:

a- more RET
b- more overlap

There must be also some discount due to engine wear. It all adds up.

I don't know your tune specifics, that is why I mentioned that a conversation with Viva might tell you some things. Dyno would too.

I do know that your setup will be a bada$$ DD.

 

His tune is aggressive enough, it's the fact he's still running an 18t on a built motor. He needs a bigger turbo and have the tune reflashed for the green injectors he has sitting in his garage. Definitely lots of potential yet to be had with his car.

And he has turbo cams. But he has NA cams on hand waiting to go in as well.


Thank you for the words. I agree that I need the cams more retarded for more top end, that's what the NA cams are notorious for: shifting the power band depending on where you have them placed. The only thing is, when I had the driveability issue, I had no power anywhere on the power curve. I couldn't even get the car into high RPMs because the car wouldn't accelerate.

I'm going to set the cams back to TDC this weekend and start over to ensure that the cams are in the correct place, which they should be, but I just want to double check. I'm at 1* ADV EXH and ~3* RET INT. I'll see how this one is.

I just emailed Viva to see what he says on how the tune affected timing and if he had any recommendations for cam timing. Hopefully if I get the timing resolved I'll have an even band all around and can benefit from them.

 

Why did I say that his tune is not aggressive enough? His ratio accel/AFR should be higher for maximum top-end. That's like having Buffalo wings, but mild. The tune could have enriched / retarded over 3000, but it didn't. It let the turbo ease off the AFR. Look at it -- instead of hockey stick, it becomes a hunchback.

Bigger injectors will shift his HP curve to the left, but again will not maximize his top end. ECU will compensate to the pre-set maps. "Re-flashing" means update the new outputs, but keep the same ratios. Again, that's fine, the guy needs to drive the car everyday.

Secondly, the choppiness in the curve. Third the gap between TQ and HP curves.

I read that guy's thread on VS. He was also running racing fuel, which I would speculate is worth 10-15 hp (5%).

BTW: regardless of what I said about RET, if I was you, since you found the sweet spot, I would let it be and move on.

How your NA with play with the "slower" spooling -- that's interesting to see. You will get plenty of tweaking opportunities, like you said.

 

Well, we got it all figured out, the timing in general was completely off. I want to put the cams at TDC and just start over, took it all apart and the timing was completely messed up. Took off the timing belt and started all over. Got it back in time, vac is sitting at 18 in/hg now, not sure what the exact timing is on the cams, but the slots are parallel with the block on the driver side, so I'll mess with more precise timing later......maybe. But the car PULLS now. Damn, definitely woke up now that it's in proper time.

 

Good to hear.