just wondering after browsing through all the dyno charts posted. i had my fd tuned by steve kan in november. put down 308hp on a dynapack at 11.5 psi. problem was that the car wouldn't hold boost as i was trying to run 14psi. i now have the boost problem solved and am running 14psi. can anyone give me an educated estimate of hp numbers at the higher boost based on the above numbers? thanks in advance if you can.

mods: street port, 3mm seals, arc intake, hard pipes, greddy smic, non-seq bnr1's, no airpump, dp, res. mp, racing beat cb, rb light flywheel, pullies, 850cc injectors all around, supra pump, power fc, profec b, etc.

 

I would not worry about the hp but would be more concerned with getting it tuned at 14 now that the boost control is working. Otherwise I would expect around 10 to 15 hp per psi, perhaps more with your porting but not more than 20.

A side note here is how important it is to get the car working before tuning. Easier said than done as it's helpful to have a tuner there while you pugh the car to ensure everything is safe. Last car I looked at had a failed IAT sensor (first one I've seen), read -37 degC holy ****, pig rich, wouldn't hold boost, ignition breakup under boost, and backfired all the time. We spent a few unplanned hours correcting the IAT before we ever did a tuning run.

 

thanks for the info. everything on the car was working right except the boost issue which was a leak. it would see 14 initially, so we were able to see afr's and duty cycles at that boost level. steve indicated to me that he tuned the car with enough head room that the extra psi should be safe once i fixed the problem.

i forgot to mention that i have an xs ignition booster as well for anyone else who might chime in.

 

twokrx7 has very good estimates.

An FD with stock twins and a non ported motor, that I used to own made 286 at approx 10.5 psi and 311 at approx 12.3 psi, which is roughly 13.5 rwhp per pound of boost.

The runs were made on the same day with AFRs around 11.2