What is the roll pin mod for the pressure regulator that keeps it from sticking?

The oem (small pin breaks) you can drill it out to take a 3/16 pin (Stronger) or the other mod is tap the hole to accept a pipe plug, flip the valve around and install the threaded plug. Have to make sure the threads are below where the pin boss is or it will leak. Sorry we are talking priming vale here in the pump with the 3/16 pin deal. The other is the pressure and boost valve in the VB. sorry i misunderstood...

Ok, thanks. Yeah, not an issue for me then, BTE high volume pump. No priming valve to worry about....

Yes Sir, same here no PV in the TSI pump either.

You still working in the kitchen down there? lol
BTW. >> Merry Xmas. Going to be 50 here on Xmas. Yee Haw. How do you like that HTH temperature?

I guess anything beats 8000 feet. lol

quote:

Originally posted by TD3550:
Yes Sir, same here no PV in the TSI pump either.

You still working in the kitchen down there? lol
BTW. >> Merry Xmas. Going to be 50 here on Xmas. Yee Haw. How do you like that HTH temperature?

I guess anything beats 8000 feet. lol

Ugh, yeah, still down in the microwave....wishing I was back in the altitude!!!! I miss home! Plan is to move back when I can, but it's gonna be a while before that can happen...plan is in place though!

Merry Christmas back to you as well!

Couple of questions for anybody that has experience with changing out pressure regulator springs. 1)If you change out the spring to a higher rated one, and don't change the boost valve, do you improve the overall pressure. 2) If you still have stock size gears in the front pump, do regulator spring changes do anything. 3)What spring rate is most recommended, say with 900-1000 hp.

The Coan spring part # I posted a picture of, depending on the boost valve in play will be 220-250. A good pump IMO has a 20 psi split from idle 1450 rpm to 2000-2200 rpms in gear. Pressure taken off the servo cover. That's just a generic way I quick check a pump. 900 hp I'd probably like 220-230 at 2000 rpms bracket racing.

This message has been edited. Last edited by: Mike Rietow,

1 yes
2 yes
3 250

OP, the higher the pressure, the higher the probability of the pressure on the backside of the servo piston overcoming the servo spring in high gear and the band dragging when it should be completely released when not in low gear.

The higher the pressure the more crucial the servo spring in play. I'm not discounting anyone else's pressure suggestion working with around 1000 hp, however I did a transmission for a guy in a car with 2500hp to 3000 hp for ten years and I found 245 psi at 2000 to 2200 rpms was perfect. We put 125 laps between service with this pressure. 9 FMX clutches in what was known as a Pro Mod drum which adds up to around 20% more clutch area in the drum over a 10 clutch drum. If you ever come across a drum like this hold onto it. They're obsolete.

mike the latest sonnax servos seem to help the bias issues.that is what i am useing.the biggest issue i am seeing with high pressure is the bands are not strong enough and roll the ends causing the end of the band to wear off.just another nickels worth .

quote:

Originally posted by rusty:
mike the latest sonnax servos seem to help the bias issues.that is what i am useing.the biggest issue i am seeing with high pressure is the bands are not strong enough and roll the ends causing the end of the band to wear off.just another nickels worth .

I figured you were using the supported pin servo which work great. Depending how high your pressure, you might consider a ratio or super servo. These will make for better clamping in low (@245psi) and as I said 245psi works plenty well enough for clamping in high gear (drum) around 2500hp. Just a suggestion depending on if band maintenance is becoming an aggravation.

This is a 1" ringless aerospace input shaft, 1.64 low 300m output PG I'm working on to service around 1150 1200hp. None of this has anything to do with what we're discussing, other than saying this transmission is good for up to 2000 2500 hp.

We're running a Super Servo on this in order to run around 215 psi or lower, depending on how high gear looks. We'll also have another transmission in play for this car good for one or two runs we'll use to qualify (best session). It'll be a couple two three hundredths quicker. That's just my approach being around em, eeking every bit of et out.

This message has been edited. Last edited by: Mike Rietow,