1991 lx 5.0

Nov 5, 2018
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0
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clovis
so i got a 91 331 stroker anderson n41 cam and ported gt40 heads and intake. im having a detonation problem at WOT with the mass air hooked up. then with it unhooked the car would run but detonate at any rpm over 3k. inital timing is a 7* and total timing is at 35*.
 
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Dan02gt

10 Year Member
Mar 2, 2003
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Greenville, NC
I'm not familiar with that DBX mass air meter, but it looks like it is tunable. Can you use the software to add a little fuel in the range that you are pinging? Have you tried adding something like race fuel or octane boost to get the octane up a little?
 
Nov 5, 2018
6
0
1
22
clovis
I'm not familiar with that DBX mass air meter, but it looks like it is tunable. Can you use the software to add a little fuel in the range that you are pinging? Have you tried adding something like race fuel or octane boost to get the octane up a little?
I’ve used torco octane booster and no difference
 

a91what

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Mod Dude
Apr 6, 2011
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35* total is too much with pump gas and 11:1 comp. Stock 5.0 WOT timing is 28* total. 30-32* with the timing bump most people do.

Lower the Total timing to 30* and the detonation will disappear. 28-30* is the most i would consider on that setup with pump gas.
 
Nov 5, 2018
6
0
1
22
clovis
35* total is too much with pump gas and 11:1 comp. Stock 5.0 WOT timing is 28* total. 30-32* with the timing bump most people do.

Lower the Total timing to 30* and the detonation will disappear. 28-30* is the most i would consider on that setup with pump gas.

I have a Modotek computer where I can tune online. I just got the car. Everything was tuned by the guys at Modotek. That’s what I’m guessing is timing is too far advanced at WOT. Initial timing at the moment is at 7* to see if that would help at all but it didn’t. So I’m thinking about moving that back up to 12-13 then bring fix the tune to come down to 30 total timing and see what happens there
 

a91what

SendMeUrDataLog
Mod Dude
Apr 6, 2011
10,206
6,105
204
31
Hillsborough county
I have a Modotek computer where I can tune online. I just got the car. Everything was tuned by the guys at Modotek. That’s what I’m guessing is timing is too far advanced at WOT. Initial timing at the moment is at 7* to see if that would help at all but it didn’t. So I’m thinking about moving that back up to 12-13 then bring fix the tune to come down to 30 total timing and see what happens there
set base timing to 10* then the total needs to be 28* start here as a baseline. I have never used a modotek, got a link??
 
Nov 5, 2018
6
0
1
22
clovis
set base timing to 10* then the total needs to be 28* start here as a baseline. I have never used a modotek, got a link??
Company isn’t around anymore. The car was in the mustang and ford magazine called the project cheaper sleeper. The car was built in 2013. Finding info on this computer and tuning is ridiculous
 

a91what

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Mod Dude
Apr 6, 2011
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Hillsborough county
gotcha, I am a megasquirt guy myself.... so if you ever have any tuning questions feel free to ask. I hang out in the digital tuning section of the forum.
 
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