MT 82 to Magnum XL.... advice thoughts

It appears my quest for 10's NA has just taken several steps backwards. While in Bowling Green, I shattered 4th gear in my MT-82. They said it was in chunks on the magnet.

I'm not going to mess around with the MT-82 and worry about breaking it again. Monday I will be ordering a Tremec Magnum XL, thus making it harder for 10's. The gear ratio's do not appear to be favorable for 1/4 purposes. To help out I will be also adding a 4.09 gear in the car, since that is the steepest they make. If the calculators and my figures are right this will be the following:

4.09, third 1.46 @ 8000 rpm will be around 108mph and shifting to 4th will drop me to around 5500. 1:1 ratio... and at 6000 will be 118mph and 128 @ 6500 which is well below my peak hp. The good news is I will only need roughly 1000 rpm.

Any thoughts or experiences with this? How much will it hurt or help?

I assume you are going with the 2.97 first gear...not the 2.66?
I honestly dont have a good answer for you ...N/A it might be a challenge. The MT82 normally is fine unless you are running a non-organic disc...like the RXT. I went through two MT82's...but i'm boosted. I went the TR6060 (same basic gearing as in the magnum) and found the 4.09's to be a perfect match with boost..it's a monster on the highways.
At your power level you should, if your not, be able to run a good organic disc and stay with the MT82. Ben C's stage two should hold up fine at your hp/tq levels.

It was a cerametallic clutch unfortunately. It was spring hub though. Still too much I guess. I don't want to have to worry about the tranny again. I don't want to do it twice, just once. I may go boosted one day with turbos.

organic clutch material probably makes a much bigger difference than the springs. But then it will be more prone to heat.

mustang1 said:

organic clutch material probably makes a much bigger difference than the springs. But then it will be more prone to heat.

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I agree now. Thought it was more of a hub and spring issue. Not the case.

I went with the clutch I chose for this reason. Would prefer the clutch be the fuse. It will still hold 600whp if I choose to go boosted but its still organic and drives like stock. No stiffer then the stock clutch with no helper spring. I am getting tired of occasional miss shifts and grind going into 5th when quick shifting. Even with the trans bushing and shifter bracing. (Still way better then stock though) The MT82 holds up pretty well but does have its quirks. Maybe my clutch pedal to shift timing is a little off when driving aggressively but I haven't had trouble with any of my other cars. Also shifting at 8k may be part of it.

Lonmon said:

I went with the clutch I chose for this reason. Would prefer the clutch be the fuse. It will still hold 600whp if I choose to go boosted but its still organic and drives like stock. No stiffer then the stock clutch with no helper spring. I am getting tired of occasional miss shifts and grind going into 5th when quick shifting. Even with the trans bushing and shifter bracing. (Still way better then stock though) The MT82 holds up pretty well but does have its quirks. Maybe my clutch pedal to shift timing is a little off when driving aggressively but I haven't had trouble with any of my other cars. Also shifting at 8k may be part of it.

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I had no problems with shifting with the stock clutch but was afraid its days were numbered. I had no problems with the MT 82 and loved it, that is until it just let go. I have read enough post on here to know to just go ahead and upgrade instead of wasting money on fixes. I like to do things once and be done.

My question is at what cost of ET? I feel that the car had 10's NA with the MT 82.
I may lose a couple of tenths or who knows with the 4.09, maybe it will be the same.

Is there any rumor of anyone coming out with 4.30's or 4.56's? I think a 4.30 would be perfect.

Evil 5.0 said:

I had no problems with shifting with the stock clutch but was afraid its days were numbered. I had no problems with the MT 82 and loved it, that is until it just let go. I have read enough post on here to know to just go ahead and upgrade instead of wasting money on fixes. I like to do things once and be done.

My question is at what cost of ET? I feel that the car had 10's NA with the MT 82.
I may lose a couple of tenths or who knows with the 4.09, maybe it will be the same.

Is there any rumor of anyone coming out with 4.30's or 4.56's? I think a 4.30 would be perfect.

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Not sure how tall a tire you run now , but if 28" going to 26" will effectively make 4.10's like 4.5's

http://www.tremec.com/calculadora.php
You can play around with this calculator but depending on what you trap ,you could gain some ET with one less shift .
For example ,if you trap 122 mph you would be @8000 rpm in third with the 2.97 first Magnum /3.73 and a 28 inch tire .

olaosunt said:

Not sure how tall a tire you run now , but if 28" going to 26" will effectively make 4.10's like 4.5's

http://www.tremec.com/calculadora.php
You can play around with this calculator but depending on what you trap ,you could gain some ET with one less shift .
For example ,if you trap 122 mph you would be @8000 rpm in third with the 2.97 first Magnum /3.73 and a 28 inch tire .

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I have played with that today.....8300 could produce 127mph. 8200 would be 125.5, so it could actually get faster.

My current drag radial is 26.7".

Just make sure you use Calimer or another good builder to reinforce the transmission. RXT or Mantic for clutch. Dakota digital box, DSS makes a drop in driveshaft, the MT82 slave cylinder works as well and get an MGW shifter with extended arm to fit properly. Easy to swap in and out, just need to wire and figure out where to put the dakota box.

Check d&d Performance. Have the complete kit at a great price. Looks to be the way I will be going over the winter. Just need to have clutch disc's resplined or purchase new disc's

michigan stang said:

Check d&d Performance. Have the complete kit at a great price. Looks to be the way I will be going over the winter. Just need to have clutch disc's resplined or purchase new disc's

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I did go with D&D and posted this under my other thread:

I have ordered the Tremec Magnum XL Kit. It is being built today. First time I have had a new transmission gone through. The Magnum comes with carbon fiber syncro's in second, so I figured it wouldn't hurt to have them put in 3rd, 4th and 5th. Also having the plastic shift pads replaced with brass pads.

To make up the difference with the gear ratio's I will be switching to a 4.09 gear. I'm having that along with the bearings sent out for REM polishing.
I don't know if that will help, but I know it wont hurt.


Now for the decision part. I had the Exedy ET 04 XD, which is 9 lbs lighter that stock and a twin disc good for all kinds of power. All I have to do is switch to an ET 03 XD disc to make it work..... or go with OEM style pressure plate with puck disc good for 647rwtq.

Good choice.
They also built mine .
Race prep includes adding 3,4 and 5 carbon fiber hybrid blocker rings . Bronze fork pads on 1-2,3-4,5-6 and reverse ...all for $500!

Dealt witb Don Walsh snr.He is a drag racing legend .I think he is in his 80's now but still as sharp as a tack !

olaosunt said:

Good choice.
They also built mine .
Race prep includes adding 3,4 and 5 carbon fiber hybrid blocker rings . Bronze fork pads on 1-2,3-4,5-6 and reverse ...all for $500!

Dealt witb Don Walsh snr.He is a drag racing legend .I think he is in his 80's now but still as sharp as a tack !

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That's exactly who I dealt with. Even requested him when I called back to order. He maybe be older, but knew what he was talking about!!

Glad you like yours, gives me more peace of mind. Did it slow you down from the stock MT 82? I have been told it won't make much of a difference because 1-3 are close and by the time you hit fourth the 1/4 is done.

The 2.66 first( I got the close ratio) with my current 3.31 rear end is hurting my 60 ft and probably my 1/8.
With a 28 inch @7600 third tops out @150 mph.
I went 10.1@148 staying in third:cheers:
Its a little better going down to a 26 inch slick (went 10.0@144)but it should get a lot better once I swap in the 4.10 pumpkin I am building.

I still think I can get a 9.8-9.9 with the current set up staying in third as one less shift has got to be worth some ET.

I am keeping the 3.31 rear end in case I want to run a 1/2 mile events.
I could stay in fourth up 190+ mph.
Link to my passes since the swap.
http://www.mustang6g.com/forums/showthread.php?t=90222