and if you pick up Maximum Boost by Corky Bell, it explains this in detail...at TDC an atmospheric engine could already be seeing 1100psi of cylinder pressure, another 30 on top of that isnt gunna hurt anything, an extra 2.9% isnt much.

 

It doesn't work that way.

If atmospheric pressure (~14.7 psi) generates 1100 psi of cylinder pressure when mixed with fuel and ignited, what do you think happens when you increase that intake pressure by a factor of 2 full atmospheres (30psi)?

Think of how much more cylinder pressure a 2.0L engine must endure to deliver the same force as a 6.0L engine. That same force is distributed across a much smaller piston surface area, so the pressure per unit of piston face area goes way up.

gsujeff55 is correct. Forcing the engine to generate a great deal of midrange torque puts a tremendous amount of load on the engine. I'd venture to say that there is probably at least as strong an argument for upgraded rotating parts where high midrange torque is expected vs. making more hp up top.

 

Exactly. Its all about cylinder pressure and engine load....not about HP. The reason there is a given HP number is because the cylinder pressure and load required of the engine to get it to that certain hp level(the line of blowing **** up) is too high.

 

We meet up at 8pm every Wednesday night.

 

yes this is all correct....im standing by my original statement, PSI by itself....is insignificant.....

power is a function of bmep x stroke x area and (cylinders x rpm/2)

i just dont like it when people are all like "oh i heard x car can only run 10 psi...oh man dude how many psi are you running, dUDE, ANNNANWZZ???"

mike

 

I am currently in the same boat... I am thinking 35R but I am not looking to do a standalone/engine rebuild.. or should I say not right now.... With my current mods and supporting mods is 500WHP do-able for a daily driver? Would a smaller turbo to get me around 450WHP do me better then a 35R that really only shines 500+whp..

 

I want a GT35r Kit so bad, but I am curious about the lag. I have been reading on here about lag issues, but I don't know how much truth there is to that. Either way I am jealous and might have to go get one now!

 

look at my question then look at my sig lag is not bad really, after a month u dont even notice because u learn to work around it by being in a lower gear.

 

sick

 

talk about thread resurrection...

 

 

lol, at least the guy knows how to use search.

I think the whole lag issue is over-exaggerated. Compared to a stock turbo, that comes on at 3500rpm, when your at 3500 with the GT35R, you will still have more torque. I'm not sure with a GT30 though, but I am sure the torque #'s are similar when it hits fulls boost and a GT35R at the same rpm.

 

yes, in race conditions, lag is overrated. But putzing around in traffic at 2000 rpms in second, and then trying to make a quick spurt to change lanes and all of a sudden, lag ain't so overrated. Just depends on what you use the car for, and what your typical driving conditions consist of.

Congrats on the numbers, sounds like your car is exactly how you want it!

 

Wow, this is an old thread. Back in the 35r days... Anyways, the lag wasnt bad at all. Hardly noticeable after driving for a few days. When I added a 2.3 stroker, the car was very responsive and the torque was incredible. I have since put a 37r on my car. Now with the lag is really noticeable, even with the 2.3. I still have to get the car tuned, hopefully Ill have numbers with the new turbo / 2.3 by next week...

 

How is the idle of the 280 HKS cams???