Whoop_ass

iTrader: (7)

now that is interesting info...
never knew timing played a role on bore, and makes sense that a engine with a higher VE can run more timing as it is dealing with flow better...

some nice posts in here...

RazorLab

iTrader: (8)

You either don't understand MBT or where taught a different meaning of MBT if you think that statement is correct.

Absolutely no way you are hitting MBT on American pump gas (94 or less) on a Evo.

Fuels that you can go up to and even beyond the engines MBT are fuels like VP import and E85. You hit MBT when adding timing makes no power increase. With pump fuel, you will always hit knock before you reach MBT, and the knock is what is preventing you from making power increases. Try turning off the knock sensor on pump gas on a Evo and see if you can hit MBT before you hear detonation.

Like JB said, on pump gas you are not hitting engine MBT but the limitation of that octane.

btw this is a great thread.

EE

iTrader: (9)

John, when you say the limit is 19-20*, on which rpm is this??


Tks

Mellon Racing

iTrader: (38)

here we go again with people trying to nail down a specific degree of timing to a specific RPM...seriously people quit trying to copy other peoples tunes and either figure out what YOUR car likes or get it professionally tuned. It's been stated in her many times now

1 - each car is different due to mods/boost/octane/altitude/compression etc...
2 - you're going to knock well before you reach maximum timing on pump gas

hate to be rude but we're going in circles

JohnBradley

iTrader: (30)

Assuming that fuel isnt a constraint you will see 19-20* by peak power + a few hundred rpm for your particular combo, somewhere north of 7,000 usually. If you are on a fuel that you cant reach or surpass MBT, then as Mellon said its whenever you hit scattered knock.

Whoop_ass

iTrader: (7)

Ye we understand Mellon but....

if you had 2 of the same cars with same mods , we not saying they will be identical but they will be close, within 1-3 degrees of each other, each car is different.
And they all act different, hence why we tune them.Take Bushcur, I am sure he has base maps set that he later on tweaks to the cars liking but he has an idea what he feels the limits of 93 would be with his stage 3 builds on pump gas.

I just asked what timing are people running on 93 with big turbo cars.
big turbo cars can carry more boost at redline and don't fall off like the stocker and maybe that is why you wont run big timing @ redline with say a 35R compared to the stock turbo.
Also big turbo cars have a way cooler charge temp than a stock turbo and that is why you can run 30 psi on 93-94 octane with out knock.

you not gonna run 30psi with the stock turbo on pump.....you use meth to increase octane and to cool charge down.
With VP import on the stock Turbo I have seen timing of 15 deg at peak torque and maybe even 35 deg @ redline. now the turbo becomes the limit and you will prob get to the point were adding more timing won't net any more power.

Mellon you have tuned a couple of big turbo cars.
share with us your timing expirences.

EE

iTrader: (9)

Yeah I know on regular fuel I'll be hitting knock before reaching MBT, I was just asking abt the MBT itself. The reason i asked for this is bcs i hv never tuned my car on anything else than 98Ron (equ. to 93), so it's nice to have an idea abt the timing you can / should run on race gas... Tks for sharing info John