Calling Geno and/or Turbofabricator! Or?

[nightrain]

Been scratching my head on my short times at the track. Geno knows the car and the major difference now is I just installed the PTC 9.5" NLU 2800 stall. It stalls right on the money and flies on the top end. Only problem is I can't launch worth a darn. 60's are 1.77 to 2.0 and a guy who watched me last Friday said no tire spin on a launch at 4400rpm, 24lbs boost on the Tbrake that yielded a 1.77 60'. Crappy part is that's the same 60's I got on my West Coast LU that stalled at 2200rpm.

Attached is the PL log for that run (11.44 ET @ 119.6MPH). I can see a dip in the AFR at launch until about 17mph and then the TT WB chip takes over. That was running C16 as well. Rest of mods are in my sig. except tires are MT ET Streets 27"x10", but remember there's no spin. Heck, if they did spin at that rpm and boost, there'd be smoke 30ft out.

I'm going back up to Mission this Friday and probably the 3rd, so any advice would be appreciated.

 

[turbofabricator]

Try bumping your initial timing up a few degrees, and pull it out after 30-40 mph. These cars need more timing than most think for the first 60 feet. Lean the A/F ratio for the first 60 ft.. too. That is probably all you need. Bump timing a few degrees at a time and watch for detonation........CAREFULLY. Don't be afraid to move timing, and A/F ratios, just do it systematically, and document what you do. Feel what the car wants. As you move timing tables, it will "feel" completely different. Read spark plugs after each run, too. Just because it says 28* timing, doesn't mean that is what it really is. If you have an aftermarket balancer (BHJ) they are known to be as much as 13* off from the factory. That will KILL bottom end. Even stock balancers have been found off. (the crank trigger ring).

 

[SGRIM]

W/O the trans brake can you power brake the car enough to light up the tires? Have you tried launching w/o the brake?

 

[geno]

Is the Alky on?If so does the light come on when your on the TB?Does it feel like it bogs out of the hole?I cant read your files?Can you see how long it takes to go from launch boost with the TB to full boost? Is it slow spooling and did you look at the tires after your runs? I know you said somebody watched your run but if your tires are fuzy they spun:biggrin:

 

[nightrain]

Try bumping your initial timing up a few degrees, and pull it out after 30-40 mph. These cars need more timing than most think for the first 60 feet. Lean the A/F ratio for the first 60 ft.. too. That is probably all you need. Bump timing a few degrees at a time and watch for detonation........CAREFULLY. Don't be afraid to move timing, and A/F ratios, just do it systematically, and document what you do. Feel what the car wants. As you move timing tables, it will "feel" completely different. Read spark plugs after each run, too. Just because it says 28* timing, doesn't mean that is what it really is. If you have an aftermarket balancer (BHJ) they are known to be as much as 13* off from the factory. That will KILL bottom end. Even stock balancers have been found off. (the crank trigger ring).

Thanks! I'll try bumping up the initial timing in first and second (I have stock computer with TT WB chip, so that's my only choice on the low end). I have an audible knock meter. I can also pull some fuel out down low.

 

[nightrain]

W/O the trans brake can you power brake the car enough to light up the tires? Have you tried launching w/o the brake?

Yes, but it seems like it takes a lot of rpm to do so while lightly on the brakes. It takes about 3500rpm to break the tires loose in the water box with the brake on. I have a line lock, but it's acting up lately. I was getting the same 60's with the brakes as with the tbrake. It was the first time out with the tbrake, so my first passes were off the foot brake and then I got bold and tried the tbrake hoping for that "hit by a freight train" launch. It was more like getting hit by a moped.

 

[nightrain]

Is the Alky on?If so does the light come on when your on the TB?Does it feel like it bogs out of the hole?I cant read your files?Can you see how long it takes to go from launch boost with the TB to full boost? Is it slow spooling and did you look at the tires after your runs? I know you said somebody watched your run but if your tires are fuzy they spun:biggrin:

Hi Gene,

Yes, alky is on and at 20lbs on the t/brake, yes the light comes on. I beleive I had it set to activate around 13lbs boost. I know you said before to hook up the brake switch to keep alky off at launch, but I thought I had it turned way down to have little effect except cooling while running C16.

Actually, going from launch boost to full boost is instantaneous. My PL file shows me I left at 24lbs boost and it stayed at 24lbs the whole run. Previous files did the same at the various boost levels I tried. I had 19lbs boost on the fist run at launch with 3.13TPS. When I went to 4.77TPS right after launch, I stayed at 19lbs. The AEM boost controller is working great. I did not look at the tires after the run, but it would be tough unless I stopped in the return lane. You know Mission. Dusty gravel in the pits.

Hopefully some of the other suggestions net me some results (increase timing, lean a bit at launch) this Friday. I'll try looking at the tires, too, and have a better videographer capture some launches.

Thanks everyone who responded!

 

[turbofabricator]

How is the fluid in the trans? Do you over fill it by 1 qt? It might just be trans slippage, too. Once the car "G's" it can move all the fluid to the back of the pan and cause a cavitiation. What pan, and filter do you use? DO the RPM's come up faster than what it should?

I couldn't read your files either.

Try turning off the Alky, too. It might be all that is wrong.

 

[nightrain]

How is the fluid in the trans? Do you over fill it by 1 qt? It might just be trans slippage, too. Once the car "G's" it can move all the fluid to the back of the pan and cause a cavitiation. What pan, and filter do you use? DO the RPM's come up faster than what it should?

I couldn't read your files either.

Try turning off the Alky, too. It might be all that is wrong.

Fluid is nice and red. No burned smell, either. It's over full by about half quart. I use a stock pan and filter. Not sure how fast rpm is supposed to come up with this converter. It seems like I can't get moving in first when leaving stop signs and such (normal driving, part throttle). It slips more than I would like, but I have nothing to compare it to, except the AC 9" I used to have that stalled at 2200rpm at zero boost. I haven't driven anyone's car that has this PTC converter. On the brakes, it stalls at 2800 at zero boost, just like it's supposed to. Halfway through 2nd and all in 3rd it pulls very nicely. I just can't leave worth a crap.

Will find out more tomorrow at Mission. No rain please! Too bad dew point comes at 9:00pm or so.

Thanks!

 

[wheelin]

Fluid is nice and red. No burned smell, either. It's over full by about half quart. I use a stock pan and filter. Not sure how fast rpm is supposed to come up with this converter. It seems like I can't get moving in first when leaving stop signs and such (normal driving, part throttle). It slips more than I would like, but I have nothing to compare it to, except the AC 9" I used to have that stalled at 2200rpm at zero boost. I haven't driven anyone's car that has this PTC converter. On the brakes, it stalls at 2800 at zero boost, just like it's supposed to. Halfway through 2nd and all in 3rd it pulls very nicely. I just can't leave worth a crap.

Will find out more tomorrow at Mission. No rain please! Too bad dew point comes at 9:00pm or so.

Thanks!

Good luck tommorow Scott!!

 

[geno]

Id turn the alky off and even after you come back to the pits you can still brush the tires off with your hand and see if the tires are fuzzy or roughed up(From spinning) and not smooth:biggrin:

 

[geno]

Well did you kick the hinges out the side of the block or what?
I hope not but did you get it to 60ft?

 

[nightrain]

Well did you kick the hinges out the side of the block or what?
I hope not but did you get it to 60ft?

Nope. Car held together even at 30lbs boost, though (had a long spike at 29-30 at one launch). Dan did a nice job on those head gaskets! Local tranny guy thinks I have fluid circuit issues and I'm going to have him check out the valve body. I did the shift kit and trans brake install, so it's perfectly possible I have something amiss in there. He says it sounds like I'm launching in 2nd gear or a band is not releasing ("roller clutches, yada, yada" over my head language), so I'm holding two gears at once. It certainly feels like it. Season is over up here, so I'll get it in to the shop at some point and be ready for next year. But, with a 2.0 60' I ran 121mph, so I think I have potential.

 

[geno]

I guess when me and Pat put new wires in the reciever groves on the heads and resurfaced them it worked It was the only answer i could come up with to run a cometic gasket with a o-ringed head Glad to hear it held up..I was going to ask if your car was starting out in 2nd gear on my last post but i deleted it just before i posted my reply.I know i have to make sure my car leaves in first because it sometimes stays in 2nd gear when i came to a stop. I guess sometimes high line presure make it hangup in 2nd..

 

[nightrain]

I guess when me and Pat put new wires in the reciever groves on the heads and resurfaced them it worked It was the only answer i could come up with to run a cometic gasket with a o-ringed head Glad to hear it held up..I was going to ask if your car was starting out in 2nd gear on my last post but i deleted it just before i posted my reply.I know i have to make sure my car leaves in first because it sometimes stays in 2nd gear when i came to a stop. I guess sometimes high line presure make it hangup in 2nd..

Just to close the thread on this one, it turned out to be a cracked 1-2 accumulator piston. It was forcing the 2nd gear band to come on while in first, so I definitely had 2nd gear starts. :frown: Starting out in 2nd, but still getting 121mph means I may have to spend the winter on a roll bar. Know anybody, Gene, that can do a nice job on that?

 

[wheelin]

Just to close the thread on this one, it turned out to be a cracked 1-2 accumulator piston. It was forcing the 2nd gear band to come on while in first, so I definitely had 2nd gear starts. :frown: Starting out in 2nd, but still getting 121mph means I may have to spend the winter on a roll bar. Know anybody, Gene, that can do a nice job on that?

Who fixed it?

mike

 

[nightrain]

Who fixed it?

mike

The good people at Barrett Transmission in Bellingham. Brad Barrett runs a fine shop.

 

[geno]

Me and a friend could handle it:biggrin: Are you going to remove the Interior? Right now while im on strike would be the best time for me to do it ASAP My friend has done alot of sprint cars and full tube chassis cars. Call me at the shop and we can talk

 

[O SO LO]

Good to see you found the problem, Scott!!