how far can you go running 94 for a n/a motor before you start to loose horsepower? or is 2 the magical number?
rob
You will lose horsepower around the time your motor craps out.
because you’re advancing the base timing you will be advancing the timing all across the board. you will likely start to see losses in the low end before you see losses in the top end. the only way to know for sure is to go to the dyno and find out.
try running 2degrees more on 89, im interested. i doubt it would knock
ADAM is also boosted.
From the little I know, you don’t want too much of an advanced timing if
you are forced induced (turbo, supercharger, etc.)[/quote]
Adam also has more than one car. His turbo car is probably running reduced timing.
yea i’m pretty sure he has MSD’s boost retard system.
I’m pretty sure ADAM is talking about his NA 240 as advancing the timing on a boosted motor is risky business.
The more you advance your timing, the sooner it will spark. In doing so, you get a more powerful explosion (therefore more power) but if you advance it too much, you will detonate. Detonation is when the fuel/air mix explodes before the compression stroke has finished. The explosion pushes back on a piston that is being driven up by the crank. Trying to go in two different directions at the same time is bad for engines.
The KA seems to love advance, especially the SOHC. The ignition is retarded to deal with 87 octane fuel. If you are willing to only run the good stuff (91 is plenty) then no you won’t damage your engine at all.
The distributor has a stopper anyway, so it’s pretty hard to go too far with it. But set it with a light just to be sure. Try 17. Take the car for a rip. If it pings (it really really shouldn’t) back it off. If it doesn’t, either go for more or stop there. Not that I recommend it, but we just ran the dizzy right to the stopper, essentially as much advance as you can give it (without mod) on an SOHC and it didn’t detonate. Sure made a lot more power.
Hehehe … the SON way of doing it? What you mean pretending you know what you’re talking about, spreading misinformation just so you don’t look dumb in front of your peeps?
Well unless these things are really really really detuned from the factory, i doubt you’ll see gains from more than 5 degrees of timing. Too much timing, just like anything, is bad. But the detonation threshhold is not the limit it is the minimum timing when you see peak torque. Anything beyond that is just creating heat and opportunity for detonation
I’d reccomend someone go to a steady state dyno and find this out for sure with a stock SOHC S13. Load it on the dyno in 4th gear at 4000rpm and hold it at wot. A steady state dyno will keep the car from accelerating (which isn’t that hard on a stock sohc S13 in 4th :P)
Turn the distributor and see when you hit peak torque then back it off to the point where it just starts to drop. Now everybody knows the best timing for a sohc! yayyyy
on the NA 240sx i run 4 degrees advanced on 94… no issues…i would guess its worth easy 8-10 hp
on the turbo car…i let JWT take care of the timing though i have advanced it 2 degrees…it made about 25whp with 2 degrees…at 15psi boost
20psi boost i still run it 2 degrees advanced however i use 114 octane race fuel…cut down with some 94…in a 50/50 mix…
on all of these i dont have any detonation issues…even running VERY hard…and hot ambiant temps