- Joined
- Mar 22, 2017
- Messages
- 285
I have been trying to dial in my Paxton 13 GT and having some issues. Last run at the track (in middle of texas summer heat, ~2000 DA) was a 118.8 MPH trap speed and still having timing issues as well as boost issues. Has anyone experienced something similar to me? Any lessons on where to check next?
Lund is doing the tune, my timing is ~11 deg to keep out knock. 11-11.5 degrees timing from 35 mph-120 mph on my run. Hard to make big MPH with that low timing. Lund keeps telling me it is bad gas but I have tried just about every big name gas station in town (Chevron, Exxon, Shell, etc). I also have been adding Torco to these different stations and none are getting me any increased timing (no negative knock sensor readings) no matter what gas I am using in town. This to me yells that it is something in the tune (maybe cylinder head temp high? or ?) not the gas. We have talked (Lund and I) about bumping the timing up to ~14 but last time we did that I was getting a lot of knock. Anyone have ideas here?
I have also had inconsistent short term fuel readings. On the road I can get some good pulls with ~.95 lambda short term fuel but every time at the track there are areas of .83 which my tuner is reading as boost leak. I installed a mechanical gauge and this last time at the track in drive (not sport drive, 3rd issue) was seeing ~8 psig at redline in 3rd gear. The redline lambda is ok it is the 4k-6500 rpm area that maybe I am seeing some boost leak according to tuner? I ordered the t-bolt clamps and they should be here wednesday for me to install for this weekend at the track. I also ordered the JLT- Vortech/Paxton Blow Through Air Box to try and get that boost up just a little.
3rd issue is at the track I have noticed if I use sport shift mode it over-revs 3-4 shift and possibly transmission is slipping? I only see 5 psig at top of 3rd if I use sport shift. I have now learned to use D only but did not know of this issue before.
Any advice helpful as I dial this thing in. First run at the track was a 117.3 in sport shift mode, now 118.8 MPH. I know the motor is bone stock other than what came with the team beefcake racing paxton tuner kit and it is the middle of the summer so using corrected numbers that is 121.3 MPH (113 mph bone stock motor, no tune).
Lund is doing the tune, my timing is ~11 deg to keep out knock. 11-11.5 degrees timing from 35 mph-120 mph on my run. Hard to make big MPH with that low timing. Lund keeps telling me it is bad gas but I have tried just about every big name gas station in town (Chevron, Exxon, Shell, etc). I also have been adding Torco to these different stations and none are getting me any increased timing (no negative knock sensor readings) no matter what gas I am using in town. This to me yells that it is something in the tune (maybe cylinder head temp high? or ?) not the gas. We have talked (Lund and I) about bumping the timing up to ~14 but last time we did that I was getting a lot of knock. Anyone have ideas here?
I have also had inconsistent short term fuel readings. On the road I can get some good pulls with ~.95 lambda short term fuel but every time at the track there are areas of .83 which my tuner is reading as boost leak. I installed a mechanical gauge and this last time at the track in drive (not sport drive, 3rd issue) was seeing ~8 psig at redline in 3rd gear. The redline lambda is ok it is the 4k-6500 rpm area that maybe I am seeing some boost leak according to tuner? I ordered the t-bolt clamps and they should be here wednesday for me to install for this weekend at the track. I also ordered the JLT- Vortech/Paxton Blow Through Air Box to try and get that boost up just a little.
3rd issue is at the track I have noticed if I use sport shift mode it over-revs 3-4 shift and possibly transmission is slipping? I only see 5 psig at top of 3rd if I use sport shift. I have now learned to use D only but did not know of this issue before.
Any advice helpful as I dial this thing in. First run at the track was a 117.3 in sport shift mode, now 118.8 MPH. I know the motor is bone stock other than what came with the team beefcake racing paxton tuner kit and it is the middle of the summer so using corrected numbers that is 121.3 MPH (113 mph bone stock motor, no tune).
