What kinda HP increase do you get when going from 15 to 25psi?

Dr. Jeckel

New Member
Jul 29, 2003
I am running my current setup at 15psi and about to add the hooker exhaust. Later I will add 50# injectors, alky and a custom chip from turbotweak.
My question is how much of a horsepower increase will I be looking at with the increase in boost? I'm just trying to get a figure on how much HP increase per psi a typical TR gets. If there is a chart or something somewhere could you please let me know.
Thanks, James.
thats pretty much impossible to answer would depend alot on your combo and tune ...mainly on which turbo and where it is most efficient
I'm not asking for an exact measurement but if somone has run there car at say 15psi(or around that) at a dyno then done another pull at 25psi(or so). What kind of a difference does psi have on hp? 10hp per psi or what? I realize different turbos have different sweet spots but most people run 25psi as a max from what I've read. Just looking for a rough estimate since I have never had a turbo car prior to this one.
Will I be looking at 100hp increase or 50 or what? This is considering i have a good tune and of course the turbo will be the same.
like previously mentioned, it depends on the combo...but the general rule of thumb is 10 horsepower for every psi of boost...which would equal about 100 horsepower difference...

i know it's close because when i went from 15 psi on pump gas on my te-44 turbo to 25 psi everyday on alcohol injection...the car was a COMPLETELY different animal...
yesterday i ran pump gas and alky with 23 degress of timing.first run was at 18#.ran 12.97@104 with a 190 60ft.with 20# i ran 12.67@106 with 1.80's 60ft.last run was 22# ran 12.49@108 with 1.79 60ft.maybe not quite what you were looking for but trying to help.
Thats exactly what kind of real world numbers i was looking for,
Also were did you run your car at. I'm not even sure the track here in amarillo is going to open this year.
I think I read on gnttype.org that a stock gn gained around 15 hp per pound of boost. As the car becomes more efficeint that number will increase.
But it depends a lot on chip timing also, if you use a low timing chip with more boost you wont gain as much as using a high timing high boost chip.
When I chassis dyno'd my car it gained 10 hp at the wheels for every pound of boost I went up. I started at 22# and went to 32#. It leveled out at that point so either I'm out of effeciency on the turbo or the valve springs are weak.
Well Dusty..give us some numbers. I would like to know what kind of power you get when you run 32psi:eek:
540hp and 610tq on a dynojet. The combo is stock appearing with ported heads, TA-64, comp 212/212 flat tappet and a CAS V4R.
Very Nice....It's amazing what you cam do with these Flat tappet cams....

See you in BG..Hope to meet you.
We'll be there. Not sure if I'm gonna run a class with mine other than T&T. I plan on relaxing and watching some racing for a change while helping a buddy with a TSM car. See you there.
i ran at Idalou.i usually run 1.60's 60ft but couldnt do it.i hope someone buy's Amarillo's track and gets it open!!next time i go i'll call you and see if you want to meet there.i'm going to run 116 next time with race chip to see what the car will do.
Well the car is being put back together after me screwing it up:)
All the stuff in my sig is going on and I am hoping to get some good results.
Amarillo's track is open but only 8th mile...I'm not going to even bother, since my car is not going to be a 60ft car....its going to be more of a top end car right now.
I am going to take a trip to lubbock for a dyno session and go to the track later this summer after I get everything all dialed in and am comfortable that the car is running its best.
Hey Kevin, was the track prepped very well?
I'm hoping for an 11 second timeslip at 25psi with street tires and stock converter, but a low 12 would be just fine.
Of course I could be way off, but it will be a fun car at any rate.
Later, James.
yes,ran anywhere from 1.60 to 1.62 60's,only prob. now is the trans took a dump.alway's something!:)