Building Boost on the Trans Brake
9 Second Club
iTrader: (10)
Joined: Apr 2009
Posts: 1,230
Likes: 3
From: Joliet,IL and Las Vegas 50/50
Sorry to thread jack but I've been tweaking my tbrake/2step setup. I'm using an LNC-2000 and have a d3 brake. I'm only seeing about 18-19* of timing while on the 2step set to 3200rpm and the car made 5-6psi without touching any of the retard and rate settings. I bumped the 2step to 3500rpm and again left the retard and rate settings alone. I'm seeing about 10-12.5psi in about 3 seconds. I could probably push more rpm but not sure if that is something I should be wary about. My logs show that there is no KR or anything, but at what point am I pushing the 2step too aggressive besides traction? I'm getting a set of MT Pro Radials and heading back to the track to try the new launch settings out. Any advice? I'm guessing since the turbo is rather small it doesn't take a whole lot of effort to build boost off the line.
Restricted User
Joined: Mar 2014
Posts: 7,192
Likes: 109
From: Ohio
Looking into a smaller pulley and try to keep up with the turbo guys.
So maybe the original poster will chime back in. Now trying to spool a much bigger turbo haha.
I think more compression, the right cam, and a 9.5 PTC and it would be in business!!
I think more compression, the right cam, and a 9.5 PTC and it would be in business!!
Put a bigger turbo on and obviously made the problem worse. lol
Switched converters and spool time was back to where it was with the pt88. Compression might help, but I'll stick with the low compression/minimum maintenance. Cam is likely to be changed. I've thought about an intake swap, but don't think that will help anything... in fact it may make it worse.
As far as switching to ptc, after your results where you were seeing 10% slip going through the traps I'm not so confident a switch to that 9.5 is what I'm looking for. I thought those things were supposed to slip like 4%. I know it's loose down low, but I will not switch gears and I won't spin the engine over 7200.
Been working with Circle D trying out some of their in house CNC'd billet stators and it has improved.
Switched converters and spool time was back to where it was with the pt88. Compression might help, but I'll stick with the low compression/minimum maintenance. Cam is likely to be changed. I've thought about an intake swap, but don't think that will help anything... in fact it may make it worse.
As far as switching to ptc, after your results where you were seeing 10% slip going through the traps I'm not so confident a switch to that 9.5 is what I'm looking for. I thought those things were supposed to slip like 4%. I know it's loose down low, but I will not switch gears and I won't spin the engine over 7200.
Been working with Circle D trying out some of their in house CNC'd billet stators and it has improved.
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Put a bigger turbo on and obviously made the problem worse. lol
Switched converters and spool time was back to where it was with the pt88. Compression might help, but I'll stick with the low compression/minimum maintenance. Cam is likely to be changed. I've thought about an intake swap, but don't think that will help anything... in fact it may make it worse.
As far as switching to ptc, after your results where you were seeing 10% slip going through the traps I'm not so confident a switch to that 9.5 is what I'm looking for. I thought those things were supposed to slip like 4%. I know it's loose down low, but I will not switch gears and I won't spin the engine over 7200.
Been working with Circle D trying out some of their in house CNC'd billet stators and it has improved.
Switched converters and spool time was back to where it was with the pt88. Compression might help, but I'll stick with the low compression/minimum maintenance. Cam is likely to be changed. I've thought about an intake swap, but don't think that will help anything... in fact it may make it worse.
As far as switching to ptc, after your results where you were seeing 10% slip going through the traps I'm not so confident a switch to that 9.5 is what I'm looking for. I thought those things were supposed to slip like 4%. I know it's loose down low, but I will not switch gears and I won't spin the engine over 7200.
Been working with Circle D trying out some of their in house CNC'd billet stators and it has improved.
I already have 10% slip at 7100 @ 3850 lbs. Just don't see the PTC being the ticket for me if I can't drop weight or spin it to the moon.
I wish you could log transmission parameters so we had a good comparison of converters.
Staging Lane
Joined: Oct 2004
Posts: 89
Likes: 0
From: In the garage
Stall speed is a balancing act but I can say there isn't any other converter that will out spool and out couple the PTC. The PTC can get to any slip number you want and still spool well. A trans brake obviously makes it easier to achieve a very low slip number without sacrificing 60'. Slip numbers aren't the overall goal though. A car with 10% slip can be faster than a car with 4% if the engine isn't operating where it wants. Keeping the engine in its sweet spot for the pass is the goal.
Stall speed is a balancing act but I can say there isn't any other converter that will out spool and out couple the PTC. The PTC can get to any slip number you want and still spool well. A trans brake obviously makes it easier to achieve a very low slip number without sacrificing 60'. Slip numbers aren't the overall goal though. A car with 10% slip can be faster than a car with 4% if the engine isn't operating where it wants. Keeping the engine in its sweet spot for the pass is the goal.
I would think having a dyno curve would help a lot with these decisions. You would know right where your combo makes power..
I'm very happy with my PTC.
Ron
Staging Lane
Joined: Oct 2004
Posts: 89
Likes: 0
From: In the garage
Often times someone will have 8% slip and want 3-4% only to have the car slow down. It's because the engine is then operating in a lower average rpm through the run and the motor is putting less power to the tires for the run. This is where you have to really study the combo and is why I try to help guys understand how everything has to work together. Converters can only be perfect for a specific application. If it's perfect at 12# of boost, it's not going to be perfect at 22# and vice versa.
