Thread: Think I went with too big of a turbo...

I know logs are restrictive, and tubulars are the way to go, but I have personally seen a log with a 57mm turbo 60a/r housing stage 3 wheel and a .48 back housing make 436 whp at 22 psi on a stock motor and bc cams. And just over 500 whp on a shot of nos.if it were a tubular it would have mademore but just to show logs will get there just with more boost .

Here's the best graph I could find on a short notice. This is TP graphed versus torque. And I had an inkling this would be the case... I had been saying power, but it actually follows the torque curve, not the power curve. Which makes sense when you think about where peak injector pulse width is needed. I was being stupid.
Ignore the plateau as max TP was reached and sustained for a while. If TP were not limited it would follow torque the entire way.


Keep in mind above they describe TP as load. But it is not nearly the same as speed-density load, which is what I'm trying to get across.

TP calc = torque
MAF voltage = power
MAP+IAT = load

And if you logged them all on a 3rd gear pull, you'd see they don't follow the same curves at all.
TP follows torque output. MAF voltage follows power output, and the pressure readings will hit peak boost and stay there to redline (setup willing).

Someone on here with the capabilities should log TP versus MAF voltage versus Boost and you'll see what I'm talking about. And if you can get power and torque in there, you'd be even better. But really, the TP and MAF lines will show you the torque and power story. It should be quite evident they are three completely different things.

Have you tested any of his out or is it all theory?

We hav made over 300 whp using a log manifold on a smaller turbo then what Vadim is using.

Nice post Ben and its very true. Totally different measurements when talking about load and air flow.

Personally I like tuning on load based stuff but the AEM also gives you a much larger scaling breakdown than the realtime ecus do. Thats why the realtime ecus are soo easy to tune because when setting them up as far as the k value to match injector and maf ratings its pretty simple after that as it does a lot of the work for you. Its just a matter of fine tuning it and there is a lot less area to fine tune.

For what its worth the realtime ecus get the job done in most applications but still not quite to the capability of a full standalone which is why I switched. COP is awesome especially with a 540v primary. Never have to worry about ignition breakup ever again and yeah just soo much more options of logging, map tracing, safety features that can save the motor such as knock detection and timing retard accordingly and much more.

I have seen a VET with an even smaller turbo (T28) and cast manifold made like 320whp @ 15psi. I do agree that a VVL needs to breathe though.

I'm a dummy when it comes to tuning, and yet I understood your explanation. Would like to see all this on a graph, pretty interesting.

This is the dead horse, I have seen one setup have an issue and it was yours
Now I haven't felt the need to keep records of others people's dyno charts from years ago so I guess I don't have actual proof besides being there, which I can not prove. While I agree with the fact that a tubular manifold is obviously the best way to go, it is not necessary. I know you have said this over and over and over and over and over because the experience you had with your setup but I have not seen this, well besides you posting on here.
Drew

I think coheed is entitled to post his results and opinions as they are well documented.

In saying that, coheed was running a gt3076r with a small housing too. This turbo is very compressor bias...well he is still getting surge on a 1.06 twin scroll set up with anti surge housing.

So you have, small housing, log (bad flowing manifold), small turbine wheel and big compressor with high over lap cams.

I think this setup would be more prone to reversion than a t28 and a log. I dont think the small t28 compressor can feed enough air into the cc to cause a problem with the log