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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.

 

Testing is the only way to know what RPM your car will want to leave the line with.

ForceFed86, that does build boost extremely quickly. Great visual.

 

Sub'd!
Trying to hit boost faster on launch.
TH400 w/ TB and 2 step (F1A Procharger).

 

A huge majority of what has been posted here is very turbo specific.
With a procharger, the only way to build more boost is to spin it faster. Increase your 2-step RPM.

 

Had to get a reply in here to find it later.
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!!

 

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.

 

Circle D is being very good with him

 

Mine is loose due to foot braking and it will get tighter as I put more power/mph to it. It's at 7.5% now. I'm sure CircleD will get it figured out.

 

You must have knocked some slip out of it by removing weight and revving it higher. I remember you saying you had 10% slip through the traps during your drag weekend. Putting more power to it will only loosen it. Revving higher will obviously tighten it and so will removing more weight like you have planned. Going back to what I said before though: I don't want to spin mine over 7200 if I can help it.

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.

 

I'll be switching to a Dominator over the winter so much more logging in the future.

 

I'm looking forward to it. lol

 

I'm not looking forward to a long winter.

 

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.

 

So true. As Dusty told me, if the car leaves well, but is struggling a bit in high gear, either turn up the boost or change the rear gears to get the engine back to it's happy rpm in high gear.

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

 

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.