How much timing is too aggressive vs. safe, etc.?

[Comp04svt]

On a complete side note, I'm also in Macomb township BTW. Passed a nice black terminator going down romeo plank on Sunday when I was in my truck. Gave a wave out the window. Was that you by chance?

 

[HPLouis]

keep in mind the 4v C heads are VERY INTOLERANT to high compression and timing.

usually for a low compression (8.2-8.5 CR - stock 03/04) engine I shoot no more than 20 degrees of timing to them on pump gas boosted, at 20lbs I usually shoot 13-17 degrees to them up top depending on what they want and if the car is in california or wyoming etc... with junk fuel. I have yet to tune one that wanted any more than that. I've had several come in with timing set at 23 degrees up top on pump and they always made more power when timing was pulled down to 20, albeit not much but anytime you gain rwhp pulling out timing thats very bad.

for the exact same engine with nothing more than a piston swap making them high compression (10:1 - 11:1 CR) I shoot no more than 11 degrees of timing to them on pump gas boosted, at 20lbs I usually shoot 7 degrees to them up top. I have never come across one that wanted any more than that.

For reference, a stock 03/04 cobra engine with a simple piston swap to up the compression to 10:1 and the blower removed makes max tq at 14 degrees of timing and peak power with no more than 19 degrees up top. Some I've done made max power at 16 degrees up top.. this is all naturally aspirated.

On e-85 I shoot 22 degrees of timing to them up to 25lbs. Over that I usually pull a couple degrees from there and make a few pulls to see what they like.

This is all based on my personal experiences with 03/04 cobras. When I used to tune at 49performance in jackson,ms the owners there personally owned 7 or 8 of them over the years that were all basically shop cars I tuned. There was at least another 20 or so that came through for tunes there as well. Here in new orleans at my shop we have 6 of them that are pretty much shop cars (owners are like family). Not to mention we've had at least another 35+ 03/04 cobras come through the shop here for tunes. We currently have 7 here now getting work done. I've also remote tuned and done drivetrain swaps etc on many more of them over the years. Suffice to say I've done my fair share of testing and tuning on them to have a pretty good grasp.

JDM told me the same thing about timing. They set up my tune with 18 degrees at WOT and told me no more than 20. I went with 21 because I didn’t hear any detonation when I bumped up the timing but after reading this, I’m going to go back to 20.

Thanks


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[SVTdreamin04]

On a complete side note, I'm also in Macomb township BTW. Passed a nice black terminator going down romeo plank on Sunday when I was in my truck. Gave a wave out the window. Was that you by chance?

O.P's car is a Terminator trapped in a GT's body.


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[Comp04svt]

O.P's car is a Terminator trapped in a GT's body.


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Ahh gotcha

 

[Shadow Grey 03]

Hey @GM2Ford, what blower are you running? How is it pullied? That makes a difference as well.

 

[DSG2003Mach1]

keep in mind the 4v C heads are VERY INTOLERANT to high compression and timing.

usually for a low compression (8.2-8.5 CR - stock 03/04) engine I shoot no more than 20 degrees of timing to them on pump gas boosted, at 20lbs I usually shoot 13-17 degrees to them up top depending on what they want and if the car is in california or wyoming etc... with junk fuel. I have yet to tune one that wanted any more than that. I've had several come in with timing set at 23 degrees up top on pump and they always made more power when timing was pulled down to 20, albeit not much but anytime you gain rwhp pulling out timing thats very bad.

for the exact same engine with nothing more than a piston swap making them high compression (10:1 - 11:1 CR) I shoot no more than 11 degrees of timing to them on pump gas boosted, at 20lbs I usually shoot 7 degrees to them up top. I have never come across one that wanted any more than that.

For reference, a stock 03/04 cobra engine with a simple piston swap to up the compression to 10:1 and the blower removed makes max tq at 14 degrees of timing and peak power with no more than 19 degrees up top. Some I've done made max power at 16 degrees up top.. this is all naturally aspirated.

On e-85 I shoot 22 degrees of timing to them up to 25lbs. Over that I usually pull a couple degrees from there and make a few pulls to see what they like.

This is all based on my personal experiences with 03/04 cobras. When I used to tune at 49performance in jackson,ms the owners there personally owned 7 or 8 of them over the years that were all basically shop cars I tuned. There was at least another 20 or so that came through for tunes there as well. Here in new orleans at my shop we have 6 of them that are pretty much shop cars (owners are like family). Not to mention we've had at least another 35+ 03/04 cobras come through the shop here for tunes. We currently have 7 here now getting work done. I've also remote tuned and done drivetrain swaps etc on many more of them over the years. Suffice to say I've done my fair share of testing and tuning on them to have a pretty good grasp.

thanks for the info. Not to hijack but where would you see a 9.5:1 motor timing wise with 17-18 psi on 93? Previous combo was 10:1 and 15 psi, timing was 14 absolute max if all air/coolant temps where good.

 

[GM2Ford]

O.P's car is a Terminator trapped in a GT's body.


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I’d say it’s slightly more than that haha!

Hey @GM2Ford, what blower are you running? How is it pullied? That makes a difference as well.

2.9 Whipple Crusher - 3.0 Pulley @ c.a. 21#’s

 

[Shadow Grey 03]

I’d say it’s slightly more than that haha!



2.9 Whipple Crusher - 3.0 Pulley @ c.a. 21#’s

Ok. Yeah, your timing will be in the lower 20s most likely on that combo on ethanol. Should make some steam too

 

[GM2Ford]

On a complete side note, I'm also in Macomb township BTW. Passed a nice black terminator going down romeo plank on Sunday when I was in my truck. Gave a wave out the window. Was that you by chance?

Wasn’t me bud! But I’m down to meet up in the future at some local stuff together! I need to see a Comp Orange 04 Cobra in person as I never have!

Absolutely lol

Yep. Also, dont be scared of timing on ethanol. That timing bump will be worth of decent amount.

Ok. Yeah, your timing will be in the lower 20s most likely on that combo on ethanol. Should make some steam too

I’m a believer in ethanol and timing now.

Welp... after consulting a few individuals, and reading some feedback from this thread. I advanced the timing 2*’s across 2k-4k & 4k-8k RPM ranges on the SCTx3.

Let me tell yah... HOLY MOTHER OF JOY!

I thought switching from 3.5” to 3.0” pulley was a noticeable difference... BUT MAN! That measly ole 2*’s increase from originally the “16-18*” peak I was at, was a serious night and day difference!

I didn’t even wot it. I went maybe 80-90% of the way down in 1st rolling into it, on a 75* sunny day, warm slicks (275/60-R15 Hoosiers)... and it was absolutely fighting the pavement. I then slowly shifted into 2nd gear and rolled into it... I “thought” it was going to gain traction well, but right around 4K rpm it absolutely was tearing the street apart and I wasn’t even wot.

It’s sorta got my attention real quick lol. It was only a quick 2 minute drive. Then I put her away.

I now thoroughly know why some people say... instead of 0-60mph... it’s 0 to “jail time” real quick. Things started moving real fast.

 

[decipha]

thanks for the info. Not to hijack but where would you see a 9.5:1 motor timing wise with 17-18 psi on 93? Previous combo was 10:1 and 15 psi, timing was 14 absolute max if all air/coolant temps where good.

that sounds to be in the ballpark. If it were me tuning it I'd start off shooting 11 degrees to it make a pull see where its at and start creeping the timing up from there.