Supra Forums banner
1 - 7 of 7 Posts

·
1,150+ rwhp club
Joined
·
4,438 Posts
Discussion Starter · #1 ·
Say I have full boost at 5000rpm. Say I make positive boost at 3000 rpm. Instead of shooting for 11.4 AF from 3000 on up out of vacuum, would the turbo not spool up faster if I made it say 12.5 AF from 3000 rpm on up while increasing fuel until 11.4 AF at peak torque.

Think the spool gain would be minimal or too dangerous for the motor?
 

·
1,150+ rwhp club
Joined
·
4,438 Posts
Discussion Starter · #3 ·
PM-Performance said:
i always lean it out and ramp up the timing to help spool. Its not dangerous if you know what to do.

On 17lbs, what AF and timing do you shoot for when ramping up to peak TQ?
 

·
Registered
Joined
·
174 Posts
PM-Performance said:
i always lean it out and ramp up the timing to help spool. Its not dangerous if you know what to do.
Or you could do a lot of negative timing and/or ramp up timing and dump a bunch of fuel, neither is recommended though.
 

·
1,150+ rwhp club
Joined
·
4,438 Posts
Discussion Starter · #5 ·
Negitive timing while driving and not launching seems very counter productive.

Dumping tons of fuel with advanced timing would be a cooling effect and not spool the turbo as fast since heat spools.

My main question is would a leaner 1.5 difference in AF make much of a difference in spool? I'm sure you could get away with 2 more degrees advanced and trim it down as you get closer to peak Tq.
 

·
Registered
Joined
·
174 Posts
JamesN1830 said:
Negitive timing while driving and not launching seems very counter productive.

Dumping tons of fuel with advanced timing would be a cooling effect and not spool the turbo as fast since heat spools.

My main question is would a leaner 1.5 difference in AF make much of a difference in spool? I'm sure you could get away with 2 more degrees advanced and trim it down as you get closer to peak Tq.
Yes. It should make a difference but how much of one is really going to depend on the setup. As long as things don't get crazy with A/F's go for it.
 

·
Premium Member
Joined
·
11,269 Posts
Leaning it out 1.5 pts, adding timing....... all of this may yield you 100 or so rpms better spool.....


By adding the timing though you will make more HP during spool up..... so that is good. Just keep your knock under careful watch. I wouldn't go leaner than 12.5 though and get her down to 11.3 by 10 or so psi. Of course I am very conservative.
 
1 - 7 of 7 Posts
Top