FooFighter

My patern is 7-10-7 (vac hoses like rocks). I just wanted to know how much hp and torque those three lbs of boost are depriving me of.

VegasFD

Your boost pattern is ***-backwards. It should be high-low-high. Is it spiking during transition?

VegasFD

Here's a link to a thread where a guy created an equation to estimate HP based on boost. It's what you're looking for I guess.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/equation-maximum-twin-turbo-power-573266/

FooFighter

Yeah, It spikes. May vacum lines suck *** and I just need to get them replaced. Thanks for the link.

FooFighter

Thanks but for me the link might as well be written in farcey. Basically I would be happy if I could just get a fill in the blank. ie.

3lbs of boost (stock rx)=How much hp.

VegasFD

It's not all that complicated. But based on your 7 psi, you're making 224 hp.

bajaman

It is not a linear progression. One single pound of boost is good for maybe....5 hp? But at 3 psi you'll be getting around 25 hp more, 6 psi is good for about 60 hp more, and 10 psi will bump you up about 120 hp.
There is a really good book by Hugh MacInnes called 'Turbochargers' that explains all the technical data.

Gadd

I don't understand the point, fix your car. It sounds as if your pre-spool and wastegate pills are missing, (assuming your running stock boost control). It also explains the spike, if your only making 7 psi on the primary, then your likely to over spin the secondary during pre-spool.

GoodfellaFD3S

iTrader: (213)

Each psi is worth around 10 to 15 rwhp. On my setup with upgraded twins, I made 366 at 13.5 psi and 421 at 17.5 psi, so 55 more rwhp for 4 more psi.

If a stock FD makes 255 motor hp at 10 psi, at 7 psi you're probably making 220-225 engine horsepower, or less than a 6-spd rx-8 .

FooFighter

Thx guys. There isn't anything wrong with my wastegate pills. I just need to replace the vac hoses... in specific the ones leading to the wastegate and bov? to cure my spike.