Thread: Re-dynoed my car

Went to the dyno today. I knew I wasn't going to put down the numbers I did before. Kinda disappointing, but kinda expected it. Got a few pics and a video.

A/F'S are 11.8-12.0

I got an issue with my boost though. If anyone can figure this out lmk.
It goes full boost at wot, spikes 2 psi, then settles to 16. After that it stays there for a few thousand rpms, then drops down to 13-14 bouncing around like hell. I'm running a Hallman MBC. I duno what could be causing this or if it's normal for a GT28R. Any input would be nice.

You can kinda see it in this video.

That looks pretty normal to me, but I'm not looking at boost gauges all day (I'm used to data logs).

Hmm, what you think about the power for my mods? I wish I could log my boost somehow lol

I would expect a little more power for that turbo at that boost level and a whole lot less peak torque. Although the boost spike at 4k rpm seems to explain the high torque number, and the falling boost might explain the lower than normal peak output. 252 WHP at 13 psi isn't too bad, but at 16 psi that's not right.

The dyno could be a bit off. How does it feel?
I see you ran a 14.07 at 101 mph. That seems to mesh with the 250 WHP readings right guys?

Well it I guess high it settles at 13. I duno what boost to say it's at haha. I turned it down a bit because I was making more tq. then hp. I guess I could say 13psi with a 16psi spike?

And after that time I ran a 14.2 @103 at a better track. 2.4' is killing me.

Are you running the hallman on the radiator support? You can get away with that with the pro rx because it has a ceramic ball (doesn't react to heat), but the regular pro has a metal ball that sticks when it gets hot. I ran into that issue with my white car. Moving it away from heat solved the problem.

just for reference point...i havent dynoed yet, but i ran a 13.7 at 103mph with a crappy 2.3 60ft on my lil t25. i spike 14psi as it settles to 12....and that was pre-street tune! after i put a wideband on, it took my boy a solid hour to get it up from 10.0. my 13.7 was on a flooded motor! lol

You also have lsd haha I'm running open diff!

And Swiss it is the pro, ceramic ball. That's why I don't get why it's doing that.

Mine is a pro too, they make a pro and a proRX. The regular pro just gets a metal ball.

If you look at this graph, the top two lines are boost pressure. Of course we turned it up some, but we also figured out the ball was sticking and causing the boost to fluctuate. We moved it from the radiator support to the fenderwell area and you can see how it smoothed out on the final line:

Yeah I meant RX, it has the ceramic ball. It's like a white/yellow color. maybe I got something stuck in it or it needs cleaned out. My buddies buschur one did that once, had a piece of vacuum line stuck in it haha.

But that graph looks a hell of a lot better.