2004 srt-4 stage 2 overboost

[sstosrt]

i have just about the same set up and im boosting like crazy too. its fast as hell but i know it cant be right.

[mikel]

What is 'like crazy'?

Logs?
How much boost are we talking....?

[sstosrt]

i dont have any logs due to my ds wont work on my new computer because of vista. i have the stock boost gauge still and it will sit on the needle past 20 psi. im guessing thats at least 25psi. i keep blowing off vacuum lines because of the boost.

[mikel]

Vista and the DV work fine together...

[sstosrt]

could have fooled me. i can get my computer to find the tool.

[duster360]

This is my log when trying out the 93oct tune from my SRT-4 with Stage-2 and t/toys. I tried several DAB settings and got interesting results. Here is a summary:

Code: Select all

Time    DAB      Rpm     Boost (kPa/psi)
2:26     2      3000    192 / 13    * looks normal, until..
2:27     2      4000    250 / 22    * I let go of thottle to prevent damage
-
3:13     1      3000    192 / 13    * with large swings
3:15     1      4060    245 / 21    * immediate let go of throttle
-
4:55     0      3500    137/  5     * looks normal, until..
4:59     0      4900    160+ / 9    * start of overboost event. stoped it.

[/size]

In closing, I think us staged SRT-4 owners should not use the 93oct tune, unless someone has figure out how to scale it for the MAP/TPS/WGA we use. Notice also that with DAB 0 the peak throttle voltage is lower than with the other settings. No knock retard recorded despite seing 21-22 psi boost.

I am scared to use this tune, and when I get a wideband I am curious to see how lean this makes by car. I guess I have to start from original tune and tune from there.

Predator model u7134 rev 9r17, tune ID 04510060AA. 2004 SRT-4 with S2 only.

Is there any cause for concern here? What causes the sudden increase in boost over 4000 RPMs?

I see little cause for concern. 20-22psi(depending on Baro) spike is common with the 93tune. No "Damage" will likely occure. The sudden psi spike at 4krpm could be considered "normal" depending on mph as the PCM will limit boost at lower speeds

I'd like to see another log with the proper PID logged I have outlined here:

PID to datalog

[derr12]

I don't know what the diablosport fella did in my modified tune, but boost operates verly close to what im telling it to now. I am stage 0.

I accedentally loaded the regular 93 tune the other day and boost was all over the place and the turbo/surge valve sounded terrible.