Engine/Transmission (1994 - 1998) Is there a formula for h.p?

[Bart]

I've done a lot of mods to my 98 12 valve. When buying aftermarket parts I'm asked "what's my h. p. ? I don't know. Is there a formula that I can put the numbers in and come up with a number?

 

[CogginsP]

Torque*RPM / 5,252

 

[JWashburn]

Just tell the vendor the mods you've made or will be making soon. If I recall correctly I learned that the 5. 9 rule of thumb was 10 hp per pound of boost. I think I've seen the same rough conversion on a thread around here.

 

[Forrest Nearing]

you just have to go off of proven combos to get a rough idea... no way to know for sure without putting it on the dyno.



I don't think the boost/HP really holds true, especially on a diesel



my truck is currently probably making about 375hp with 42psi... Fulmer's truck is making 650hp with 46psi



fuel makes power

 

[sam616g]

I believe the 10 hp / lb of boost rule of thumb was assuming a stock turbo with 16 cm exhaust housing. And if I remember correctly the 16 cm housing would lower your boost by about 4psi. When my truck dyno'd at 260 hp my boost was at 30 with a stock turbo.

 

[Forrest Nearing]

the boost/hp rule typicly applies to gassers because they are on a fixed A:F ratio for peak power... more air = more power at a fixed A:F ratio



a diesel does not suffer from a fixed A:F ratio, so it doesn't really apply. you can take a bone stock engine and pinch off the wastegate and make another 5-7psi of boost, but it's not going to make an additional 50-70hp.