Max psi on a pt-54?

[WSLN 6]

I was wondering when a PT-54 runs out of efficiency?
I have pushed mine past 29psi on pump gas and alky (A little xylene too I guess) with no knock.
The car doesn't run a whole lot faster than at 27psi, so how much are the factory ported elbow and unported heads holding me back?
I can't seem to break the 116mph mark at the moment.

 

[GRNDNL]

I went 11.0's @ 122 with a 54 and unported heads, 30+ psi....I picked up .3 and 3 MPH going from a 3500 stall to a 3200. Hows your 60ft?.....

 

[WSLN 6]

60ft was about a 1.79 at the time. I am locking the converter at 80mph, so there is no slippage after that mark.
The chip is 25 degrees in 1st/2nd and 24 degrees in 3rd/4th.
We are at 1650 feet above sea level if that helps at all.

 

[c&cgn]

Stock DP or a 3" bolted to to the stock elbow? That elbow is definately hurting you on that size of turbo. A THDP would likely make a world of difference.

 

[WSLN 6]

It's kind of a hybrid. The stock elbow exit is 2 3/4" and the downpipe is a non-mandrel 3".

 

[BLACK6PACK]

Don't know if this helps any, but last time at the track (months ago in the heat) I was running 12.1 @115 on 93 octane and alky with very little tuning. It was the first time at the track with the Max Effort. This was done on 23-24 lbs of boost, 23* timing and nittos. the 60' times were between 2.0 and 2.1, I couldn't hook at all.

 

[turbov6man]

I would say that a 3" DP, TH style or one with an external gate would definately be a gain.

 

[GRNDNL]

Originally posted by WSLN 6
60ft was about a 1.79 at the time. I am locking the converter at 80mph, so there is no slippage after that mark.
The chip is 25 degrees in 1st/2nd and 24 degrees in 3rd/4th.
We are at 1650 feet above sea level if that helps at all.

To run any kind of number you'll need to work on your 60fts, I ran 12.00's @ 114 with street radials in the same tune.

Whats the RPM drop between gears?...The stock heads don't make any HP above 4800rpm, with the loose convertor my rpms never went lower than 5000. You need to have a strong midrange charge because your going to run out of breath on the top end. You running 26" or 28" tires?

If you can (brave?) bump the timing up to 26 or 28, watch the knock close or you'll be picking up parts........

Yes, a TH Down pipe will help, mine will be for sale this winter...

 

[WSLN 6]

I may be interested in the downpipe this winter.
I was running 26" et streets, unprepped track.
I now have 28" nitto's so we'll see on friday what happens to the mph.
This is the only chip I have for now, so the timing part of the equation is stuck I guess.

 

[Eric Stage I]

Sean,

Along the lines of what GRNDNL said, pay attention to rpms. The 28" tires should help.

Also, with that kind of boost, ignition is super critical. Stick some good plugs in there and gap them down to around .028-030". Maybe even throw a new coilpack on there.

If you think it will stand more timing, we can take care of that, just let me know.

Keep me posted!

Eric

 

[WSLN 6]

Thanks Eric, now the others will see why it's so easy to recommend you for chips....
I might try and tighten the gap a bit before I hit the track, coilpack is good, no missing at all.