PDA

View Full Version : Spool rpm vs. initial rpm vs. gear selected


gpny
10-18-2006, 03:42 PM
I always hear about people saying "I want a turbo that spools by X rpm"
I was wondering if there is actually a standard gear/beginning rpm for people to really compare apples to apples with regards to spool time...

I mean, in first gear from a standstill, my car probably has full boost by 3500rpm, but I can't really tell because the tires start spinning around there and I'm at the rev limiter right away.
In second gear, from a 2000 rpm roll, I'm at full boost by around 4000rpm??? don't know because same thing, the car loses traction.
In third, from 2000 rpm, I would say full boost comes around 3000rpm?

Is there any reference as to where people could get consistent values. Boost is definitely gear dependent, and starting rev dependent.
It would be nice to judge turbos with a more consistent approach.

I believe it would be great to post up spool times from a 2000 or 3000rpm, or maybe even a 30mph, 3rd gear roll. That would help eliminate wheel spin for most of us, and would really make for a better comparison between turbos. Also necessary would be listing which levels of boost you hit when (IE:
In 3rd gear from a 2000 rpm roll, I hit 8psi by 2800rpm and 15psi by 3000rpm)

What do you guys think?
Try to keep responses mature and technical please...;)

mikeD16Z6
10-19-2006, 06:36 AM
I think since every car/setup/tune is different people will get different values for the same turbo. They should be in the same ballpark though, I'd say within 1000 rpm.

Boost is definately gear, or should I say load, dependent. For me it's hard to get boost in first. I get 10 psi by 4000-4500 rpm. Second and third gear, 10 psi by ~3000.

superdewey58
10-19-2006, 07:13 AM
yea different mainfolds, downpipes, ICs and piping setups will changes those #s as well

gpny
10-19-2006, 08:04 AM
My post is about trying to get a consistent measurement for when people list their setups/measurements... Then perhaps we do a sticky in the future as to how people should post up their spool times.

Of course they will not be the same depending on setup, but I think it would be beneficial to get people to post their results more consistently based on a certain gear/start rpm/start speed. This way comparisons would be more even.

This obviously only works with manual cars.

mikeD16Z6
10-19-2006, 09:01 AM
This obviously only works with manual cars.

I guess I'm out then :(

:lol: