Tuning questions before I hit the track

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BracketNova
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Tuning questions before I hit the track

#1 Post by BracketNova » Thu May 06, 2010 11:00 pm

I've got an egt now and I'm pretty excited that I'll have some idea of what's going on in my cylinder. Anyway if I've researched right I'm shooting for 1150 peak on E85. I'm mainly wondering about timing. I was running 38 degrees last year. Many people at the track told me to go higher to the tune of 42 degrees. 42 seems like alot to me but they were saying since I only have 8:1 compression and no adders my engine NEEDS this much. Can I increase timing and watch the egt untill I see a drop in performance. How do you juggle the jet/timming effect on heat (I suppose someone will tell me to get a wideband for the jetting). I am imppressed with my carb guys work...and he set the jets according to my specs...so my plan is to bump timing till I get around 1100-1150 any problems with that?


TIA Greg
"I always compare drag racing to lighting $100 bills on fire, only it's more expensive." - Craig W.

Check out my website...
http://www.findmoneyraces.com


'71 Nova E85
6.69 @ 100.2 MPH 9/6/14
1.4257 60'
1700' DA

13:1 439 BBC
3330 lbs

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supernova
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Re: Tuning questions before I hit the track

#2 Post by supernova » Fri May 07, 2010 5:41 am

Hey Greg,
I would tune the motor to run it's best and not worry so much about the egt temp. Yes, keep an eye on it but your engine might not like that high a temp. All motors are different and one egt fits all will not work with all motors....
We ran an alky blown SBC a faw yrs back that didn't like anything over 1000 deg. The higher the temp the slower it ran. A buddy of mine has a pro mod that ran the same alky but his motor ran best at 920 deg. and I've seen some that like 1050 to 1100 deg.
Temps are good to know but shooting for a temp that someone gave you could be bad for your motor. Tune to run it's best and record every pass including the egt and use it to help but don't tune to it, your motor way not like it.

Yes, O2 sensers are good for your air/fuel mix...... I have 2 of them
Blackhoodmafia!!!! :mrgreen: :mrgreen:

1972 Nova SS
572 C.I. BBC

Best to date: 1/8
et: 5.28
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new wt. 3340 lbs

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CDR Performance
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Re: Tuning questions before I hit the track

#3 Post by CDR Performance » Fri May 07, 2010 6:48 am

EGT, WB, timing light, dyno they are all just tools. Some help more than others.

Tune until performance drops. Read the plugs. They are in the heat of the action and will tell the good and the bad.
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spib
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Re: Tuning questions before I hit the track

#4 Post by spib » Fri May 07, 2010 1:39 pm

I was talking to my engine builder the other day and he said one of the bigest mistakes people make is they put to much timming in there motors and they make a big boom!!!!!!
I saw a very high dollor motor make a big, big mess on our track last yr, for some reason he put his timming up to 44 degrees, and man did he make a mess
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want-a-be
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Re: Tuning questions before I hit the track

#5 Post by want-a-be » Fri May 07, 2010 5:23 pm

I'd bet those who bump their timing up that high aren't jetting their carbs up any at all. That's why they they are blowing their stuff up. Advancing timing is the same as leaning the carb, and retarding the timing is the same as fattening it up.

Don

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BracketNova
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Re: Tuning questions before I hit the track

#6 Post by BracketNova » Fri May 07, 2010 6:54 pm

want-a-be wrote:I'd bet those who bump their timing up that high aren't jetting their carbs up any at all. That's why they they are blowing their stuff up. Advancing timing is the same as leaning the carb, and retarding the timing is the same as fattening it up.

Don


This is my point...how do you play the balancing game. Do the timing till the performance drops, then switch to jetting till performance drops...then repeat?
"I always compare drag racing to lighting $100 bills on fire, only it's more expensive." - Craig W.

Check out my website...
http://www.findmoneyraces.com


'71 Nova E85
6.69 @ 100.2 MPH 9/6/14
1.4257 60'
1700' DA

13:1 439 BBC
3330 lbs

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