RayFranchi
Active Member
- Thread starter
- #1
Hello everyone
I just joined 6g, hope someone can help me figure this out. Grab a coffee or a beer cause this is a long technical read :-)
Need help figuring out why the addition of off-road long tubes yielded identical numbers With near identical DA
Here are two race days about 3 weeks appart with near identical DA. There was a difference of 100 DA between both race days.
Tune / intake / tires
Run 1
60’ 1.67
1/8 98mph
1/8 7.25
1/4 123 mph
1/4 11.26
Run 2
60’ 1.72
1/8 98mph
1/8 7.28
1/4 123 mph
1/4 11.25
Run 3
60’ 1.7
1/8 98mph
1/8 7.3
1/4 124 mph
1/4 11.27
Added Off-road long tubes with revised tune
Run 1
60’ n/a
1/8 98mph
1/8 7.2
1/4 123 mph
1/4 11.21
Run 2
60’ 1.69
1/8 97 mph
1/8 7.24
1/4 123 mph
1/4 11.27
Run 3
60’ 1.69
1/8 97 mph
1/8 7.3
1/4 123 mph
1/4 11.29
When I run the car I can see by looking at the nGauge that it’s adding timing until 1/8 once in the big end it starts to pull timing badly. I see it drop from 27 all the way down to 22
So I’ve been looking at my log from one of the runs
Here are the timing numbers
1st gear timing climbs all the way to 28.3
2nd maxes out to 27.3
This is where it starts taking a dive
3 rd maxes out to 25.3
4 th maxes out to 24.3
5 th maxes out to 24. 8 but drops to 23 3/4 through the gear
6 th it takes a total dive and maxes out at 22. 3 but I cross the line at 6700
It pulls back 5 degrees from the beginning of the run to the end.
It’s adding timing from 1 st to second ONLY. I’m seeing -0.5 to -2.5
Once it hits 3rd it’s starts pulling timing. I’m seeing 0.795 to 2.732 in 6th. 2.732!
Some say false knock due to possible exhaust touching the body. I have just spent an hour going through every inch or the exhaust and even the clamps are at least 2” away.
Some say bad gas, I use boostane. Could I be using too much? I’m wondering if the damn boostane that I’m adding is counter productive and really does not mix well wit our 94 high ethanol fuel?
Their chart does not list 94 so I used 93 to 100 and added 4oz per 5 gallons. I mean could it be burning soooo hot within the cylinder that is causing it to retard timing? Can this be seen in the tune?
I started the day yesterday with only 4oz in about 5 gallons. When I saw it pulling timing I added 4 more. Heck if the issue is this it will only get worst while trying to make it better by raising the octane
Some say high intake air charge but I’m seeing it go from 100 at the line down to 82 in 6th so it’s not pulling timing due to heat.
To close this issue was there prior to header install. I just didn’t make a big fuss since 11.25 on a tune and intake is pretty damn good. Now that I ran identical Times with headers it made me rethink this. I was also running boostane pre headers.
Thanks!
I just joined 6g, hope someone can help me figure this out. Grab a coffee or a beer cause this is a long technical read :-)
Need help figuring out why the addition of off-road long tubes yielded identical numbers With near identical DA
Here are two race days about 3 weeks appart with near identical DA. There was a difference of 100 DA between both race days.
Tune / intake / tires
Run 1
60’ 1.67
1/8 98mph
1/8 7.25
1/4 123 mph
1/4 11.26
Run 2
60’ 1.72
1/8 98mph
1/8 7.28
1/4 123 mph
1/4 11.25
Run 3
60’ 1.7
1/8 98mph
1/8 7.3
1/4 124 mph
1/4 11.27
Added Off-road long tubes with revised tune
Run 1
60’ n/a
1/8 98mph
1/8 7.2
1/4 123 mph
1/4 11.21
Run 2
60’ 1.69
1/8 97 mph
1/8 7.24
1/4 123 mph
1/4 11.27
Run 3
60’ 1.69
1/8 97 mph
1/8 7.3
1/4 123 mph
1/4 11.29
When I run the car I can see by looking at the nGauge that it’s adding timing until 1/8 once in the big end it starts to pull timing badly. I see it drop from 27 all the way down to 22
So I’ve been looking at my log from one of the runs
Here are the timing numbers
1st gear timing climbs all the way to 28.3
2nd maxes out to 27.3
This is where it starts taking a dive
3 rd maxes out to 25.3
4 th maxes out to 24.3
5 th maxes out to 24. 8 but drops to 23 3/4 through the gear
6 th it takes a total dive and maxes out at 22. 3 but I cross the line at 6700
It pulls back 5 degrees from the beginning of the run to the end.
It’s adding timing from 1 st to second ONLY. I’m seeing -0.5 to -2.5
Once it hits 3rd it’s starts pulling timing. I’m seeing 0.795 to 2.732 in 6th. 2.732!
Some say false knock due to possible exhaust touching the body. I have just spent an hour going through every inch or the exhaust and even the clamps are at least 2” away.
Some say bad gas, I use boostane. Could I be using too much? I’m wondering if the damn boostane that I’m adding is counter productive and really does not mix well wit our 94 high ethanol fuel?
Their chart does not list 94 so I used 93 to 100 and added 4oz per 5 gallons. I mean could it be burning soooo hot within the cylinder that is causing it to retard timing? Can this be seen in the tune?
I started the day yesterday with only 4oz in about 5 gallons. When I saw it pulling timing I added 4 more. Heck if the issue is this it will only get worst while trying to make it better by raising the octane
Some say high intake air charge but I’m seeing it go from 100 at the line down to 82 in 6th so it’s not pulling timing due to heat.
To close this issue was there prior to header install. I just didn’t make a big fuss since 11.25 on a tune and intake is pretty damn good. Now that I ran identical Times with headers it made me rethink this. I was also running boostane pre headers.
Thanks!
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