Some changes for LemonWedge

[LemonWedge]

thanks Doug , certainly something to think about . I have a Griner rmvb in the footbrake trans and i believe a A1 in the transbrake (current use ) trans .
Sorry for the hijack Lemonwedge

Tex

No need to apologize, Tex. I’m enjoying the conversation. This project of mine is going to take all winter, so we might as well chat.
I run a T/A Forward LBA valve body. I don’t see the 500 - 800 RPM lag that Doug describes @ 1/2, but I will concur that the 2/3 Shift is more instantaneous. It’s strange for me to hear that you guys making way more power than I are actually hitting the same shift points that I do, and running softer gearing than I’m moving to. Makes me wonder....

 

[440rb]

You would be amazed at how long the 1/2 shift takes to complete with a factory based valve body. The quicker the car the more rpm between the shift light an the actual shift. The shift takes the same amount of time for the band to grab the drum regardless of ET range. In my case it was close to 800 rpm. The 2/3 range is much closer, about 200 rpm. We even modified the T/A valve body by milling all the 2nd gear servo feed passages larger. It now takes about 500 rpm. Fortunately my shift light is adjustable for different rpm/shift. You guys may want to try 1/2 earlier.
Doug

We set our light from 6000 to 5800, driver just had to get used to shifting 1>2 earlier and light being on longer going through top end, car picked up some....takes a lot of testing/runs to sort what it really likes, around 11 runs to date is not nearly enough.

 

[dvw]

The reverse pattern w/o LBA has zero overlap on 1/2. The shift is seemless. Either the intermediate band or the low roller clutch is providing rotation of the output shaft. With LBA, the low band must release and the intermediate band apply. In theory this should be even slower, or have overlap. Has anyone else recorded their shifts? My light is set at 6300/6650. If I hit it right both will occur at 6900. In really good air (150mph) it needs a 7400 chip. 4.30, M/T 10.5wx31. Same band has been in the trans for over 500 passes. Looked like new at 400 passes. It also runs an aluminum drum with a lightened sun shell. So the mass of these two is significantly less than stock, about 1/2 the weight.
Doug

 

[66Satellite47]

The reverse pattern w/o LBA has zero overlap on 1/2. The shift is seemless. Either the intermediate band or the low roller clutch is providing rotation of the output shaft. With LBA, the low band must release and the intermediate band apply. In theory this should be even slower, or have overlap. Has anyone else recorded their shifts? My light is set at 6300/6650. If I hit it right both will occur at 6900. In really good air (150mph) it needs a 7400 chip. 4.30, M/T 10.5wx31. Same band has been in the trans for over 500 passes. Looked like new at 400 passes. It also runs an aluminum drum with a lightened sun shell. So the mass of these two is significantly less than stock, about 1/2 the weight.
Doug

Doug, if I understand correctly you use a low band apply valve body which causes the "delay" on the 1/2 shift. My antique Turbo Action Cheetah valve bodies were not LBA style as I recall. If that's correct, that explains our difference of opinion in previous threads. Thanks for clearing that up. I'll pay more attention to that with my CRT valve body, it does seem to have a bit more lag time. I'm sure my current motor doesn't spin up near as fast as yours either.

 

[dvw]

Race car is a modified Turbo Action. I run a CRT LBA in my street car. It previously had a T/A Chettah. Defiantly not as crisp on 1/2 now. It actually feels harder. Anytime components have to switch on/off it won’t be as good, close maybe. Look at all the discussions over 727 2/3 overlap. Unless the newer valve body’s are billet there really isn’t a different path for fluid to arrive at the servo. I suppose the band could be tightened some. However it’s at a point where band and clutch life is terrific.
Doug

 

[Aron Gleason]

My turbo action full manual reverse valve body has no 1st gear compression. 1-2 and 2-3 shifts have no lag and are firm.

 

[66Satellite47]

Doug is your Turbo Action same as an old Cheetah? Your in box is full.

 

[dvw]

Yes, and I’ll empty my in box.
Doug

 

[383man]

Good luck with the changes LW and I hope all goes well for you. Myself I run the Hoosier 30 x 9 radial slicks and thats with 4.30 gears. I like how it works on that setup for street and strip. Ron

 

[LemonWedge]

Thanks Ron. I ordered my US Cartools kit today. Its gonna be a bit nervy taking the cutting wheel to my frame rails. But I think I’m ready for this project.
I’ve looked long & hard at gearing. I think the car is nearly perfectly geared right now with 4.10’s and 28” tires. Moving to 30” tires, 4.30’s would be a step taller, which is counter to this entire project. While with 4.56 sounds really deep, it’s only a couple hundred RPM deeper @ 120 mph, and at the same time I’ll be moving from my RPM dual plane to an M1 single plane, so I think it’s the right step to take.
The most common combo with most of my buddies seems to be 4.30’s with a 28” tire, which is actually deeper than the combo I’m going to.
If anybody reading this has further input on gearing, Feel free to share.

 

[LemonWedge]

I know you mentioned running 29.5 10.5 MT and a 27 inch front tire here's mine 1 using a 10 inch rim and the other with a 12 inch rim and also how mine sits with a 28 front runner. Good luck my Fab guy used the US cartool kit on mine and didn't move rear axle back

what size rear tire are you running?

 

[66Satellite47]

LW, I expect you will be happy with the 4.56 and the 30" tire. I ran 4.88's with my 11.5x29.5W Stone's (30.4" dia) 10.80@126, 7000 RPM.
Your 4.56 will be good.

 

[67MPRFAN]

what size rear tire are you running?

I can fit the 29.5/10.5W tire on a 12 inch rim, but right now I just have a MT 28x10.0 with a 10 inch rim on the car now because of being cheap . the rpm isn't bad with that 28 inch tall tire and 4.30's

 

[67MPRFAN]

A picture from behind with the 29.5x10.5w tire with 10 inch rim.

 

[malex]

LW you’ll like your 4.56 combo.

 

[67MPRFAN]

Here's my 28 inch tall front tire

 

[JackpotJim]

Thanks Ron. I ordered my US Cartools kit today. Its gonna be a bit nervy taking the cutting wheel to my frame rails. But I think I’m ready for this project.
I’ve looked long & hard at gearing. I think the car is nearly perfectly geared right now with 4.10’s and 28” tires. Moving to 30” tires, 4.30’s would be a step taller, which is counter to this entire project. While with 4.56 sounds really deep, it’s only a couple hundred RPM deeper @ 120 mph, and at the same time I’ll be moving from my RPM dual plane to an M1 single plane, so I think it’s the right step to take.
The most common combo with most of my buddies seems to be 4.30’s with a 28” tire, which is actually deeper than the combo I’m going to.
If anybody reading this has further input on gearing, Feel free to share.

Are you going to add a roll bar or cage at some point? Sounds like you're close to the ET and speed where the track tech guys might say you need one. If you already have a cage I couldn't see it from your photos. The car will look great with the bigger tires in the back.

 

[LemonWedge]

Are you going to add a roll bar or cage at some point? Sounds like you're close to the ET and speed where the track tech guys might say you need one. If you already have a cage I couldn't see it from your photos. The car will look great with the bigger tires in the back.

yes, it’s got a bar in it. I crossed that threshold a couple of years ago.
I’m going to have to come to a decision on wheels pretty soon. I sold my old wheels this week, so there’s no going back now. These two are currently the options I’m leaning toward. The issue with the TT’s is that the 10” version is on 3-3/4” BS. I’m not sure I like the idea of a 6” deep dish look.
And no, I’m not going to spend forged wheel money.

 

[malex]

yes, it’s got a bar in it. I crossed that threshold a couple of years ago.
I’m going to have to come to a decision on wheels pretty soon. I sold my old wheels this week, so there’s no going back now. These two are currently the options I’m leaning toward. The issue with the TT’s is that the 10” version is on 3-3/4” BS. I’m not sure I like the idea of a 6” deep dish look.

View attachment 1019809 View attachment 1019810

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LW I had TT's on mine, the same ones with the same BS. They're one of the nicest rims on our cars but they are heavy. I recall that my front with a 28 X 6.00 MT SR radial was about 40 lbs each. That sure adds up quick.

 

[Fizz66Coronet]

Your going to at least need 5.5 bs to fit 295 60r 15. You might want to try getting rid of the hump on outer fender. My wheels don't have that huge dish to them. I thought they would have.