Anyone regret their T56 magnum XL swap?

[KKell83]

Hi all,

I was pretty set on going with a T56 swap in my 2015 3.73 car but now I'm just not sure over say a built MT82 because of the T56's WIDE gear ratio. I've done as much searching as my brain can handle so I just wanted to ask for those who went with the T56 if it's 'too much gear?' I do not want to change out my rear end gearing either but if that's the best route to take I suppose...

Just after looking at gear ratios, the 2.97 T56 transmission has the same gears (1-4) as my buddies old vortech powered Challenger 392 and even with that I remember his 3rd to 4th was quite poor - it would pull like a train up till that shift and lose all momentium. So, Ideally, I don't want to spend $6k just to hate my decision. Although, on the second hand, it seems like Calimer has increased his stage 3 prices :/ or at least I don't recall them being $4700.

I am currently at 724whp and still aiming around low to mid 800's on E85. Using Tremec's calculator I can see with my engine rpm / gear and tire size, and with the 2.97 T56 3rd is around 50mph gap! I just know my car will suffer once I throw it in that gear down the track.

Ideally, it looks like the perfect combo for my setup would be the T56 2.66 1st if I decided to swap to a 4.30 gear but idk... from the stuff below, if I kept my 3.73's just buiiding my MT82 seems best since I cannot see this car trapping 135+ traps. What do others say here with a centri setup?

Thanks,
Ken

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[80FoxCoupe]

Auto car here but have raced a stick for many years. Staying with 3.73, the mt82 is the clear choice as long as it will stay together. At 800whp it will most certainly trap higher than 135. You will be shifting into 5th with the mt82, but that won't hurt et or trap speed.

 

[J17GT]

I have the 2.97 first gear wide ratio Magnum XL and went from 3.73 to 4.09 rear gears with the swap. I really wanted that shorter first gear to get this heavy car off the line, but I know I'm sacrificing power down track due to the gear spacing. So not sure if that was the right call or not... That drop on the 3-4 shift is significant. With the MT82 (before it grenaded) I trapped 130, almost 131 in decent air riding the limiter at 1000' or so not shifting into 5th. With the Magnum I've only been able to trap 129. But at the end of the day, I'm not some heads up racer so it's not the end of the world.

In hindsight, the 2.66 close ratio trans has the better overall gear spacing, but would need more rear gear. But then when cruising you'd probably want something taller than the .63 6th gear. I think you can get a Magnum with a .50 6th gear if you want. So change to 4.30 rear gear and .50 6th gear could be a good setup.

I did not want a MT82 in my car and have to deal with shifting into 5th gear. Also, with the integrated bellhousing of the MT82, you are technically not legal to run faster than 11.49 (if I remember right). The Magnum swap allows you to run a SFI approved bellhousing.

I'm putting my whipple car on e85 this winter and am shooting for 800ish to the tire. I'm sure the Magnum will gobble up the power like a juicy steak!

Best of luck with your decision!

 

[KKell83]

I have the 2.97 first gear wide ratio Magnum XL and went from 3.73 to 4.09 rear gears with the swap. I really wanted that shorter first gear to get this heavy car off the line, but I know I'm sacrificing power down track due to the gear spacing. So not sure if that was the right call or not... That drop on the 3-4 shift is significant. With the MT82 (before it grenaded) I trapped 130, almost 131 in decent air riding the limiter at 1000' or so not shifting into 5th. With the Magnum I've only been able to trap 129. But at the end of the day, I'm not some heads up racer so it's not the end of the world.

In hindsight, the 2.66 close ratio trans has the better overall gear spacing, but would need more rear gear. But then when cruising you'd probably want something taller than the .63 6th gear. I think you can get a Magnum with a .50 6th gear if you want. So change to 4.30 rear gear and .50 6th gear could be a good setup.

I did not want a MT82 in my car and have to deal with shifting into 5th gear. Also, with the integrated bellhousing of the MT82, you are technically not legal to run faster than 11.49 (if I remember right). The Magnum swap allows you to run a SFI approved bellhousing.

I'm putting my whipple car on e85 this winter and am shooting for 800ish to the tire. I'm sure the Magnum will gobble up the power like a juicy steak!

Best of luck with your decision!

thank you sir, I appreciate your help. I do feel the 4.30 rear would be good, it’d make my 4th gear end around 145ish which is nice since I have a centri car. I know there’s the 4.09 like you so… ill have to think about it.

 

[exxit]

Following as I'm currently trying to figure out the same thing...

My car won't be used for dig racing or grudge racing... but I do want to have ~900whp on my lowest pulley and tune.

I watched a saga of someone who went through things on his calimer stage 3, he ended up being told by Calimer that the trans "isn't made to be shifted hard into 5th"... I see folks mentioning needing 5th to clear the quarter...

On lower HP settings I plan to take the car to road course events a couple times a year.


I feel like I'm a prime candidate for a calimer stage 3 over the magnum XL (and the headaches that come with install/tune) but there are multiple folks online advising strongly against it as calimer will not warranty their work and people claim consistency issues.

 

[KKell83]

Following as I'm currently trying to figure out the same thing...

My car won't be used for dig racing or grudge racing... but I do want to have ~900whp on my lowest pulley and tune.

I watched a saga of someone who went through things on his calimer stage 3, he ended up being told by Calimer that the trans "isn't made to be shifted hard into 5th"... I see folks mentioning needing 5th to clear the quarter...

On lower HP settings I plan to take the car to road course events a couple times a year.


I feel like I'm a prime candidate for a calimer stage 3 over the magnum XL (and the headaches that come with install/tune) but there are multiple folks online advising strongly against it as calimer will not warranty their work and people claim consistency issues.

yikes! That’s nuts. Makes sense about 5th gear, I heard the stronger gear set is 1-4th only. We basically have the same end goals yet I will be using mine at the track. I think you may be fine with a Calimer stage 3 if you use a higher end organic twin or triple disc. I’m sure the little give from the organic will help with any 5th gears going out the window, or just re-gear the rear end. 3.73s revving to 8k is like low to mid 140s in 4th. So…

 

[exxit]

yikes! That’s nuts. Makes sense about 5th gear, I heard the stronger gear set is 1-4th only. We basically have the same end goals yet I will be using mine at the track. I think you may be fine with a Calimer stage 3 if you use a higher end organic twin or triple disc. I’m sure the little give from the organic will help with any 5th gears going out the window, or just re-gear the rear end. 3.73s revving to 8k is like low to mid 140s in 4th. So…

I'm in a base model with 3.55s, already winding out 4th in the canyons it seems, I imagine I'll get into 5th here and there quickly with boost. I guess I could go 3.15s or something similar. Not sure how well that would go at the road course.

I do also like that it'll allow you to keep rev match and NLS vs the magnum

 

[KKell83]

I'm in a base model with 3.55s, already winding out 4th in the canyons it seems, I imagine I'll get into 5th here and there quickly with boost. I guess I could go 3.15s or something similar. Not sure how well that would go at the road course.

I do also like that it'll allow you to keep rev match and NLS vs the magnum

3.15 would be awful (imo) even with boost.

 

[exxit]

3.15 would be awful (imo) even with boost.

I mean i got some time to figure it out before I get the centri blower put on, do fuel, drive shaft, half shafts etc... then I'll either let the mt82 live as long as it can, and change it when it blows up or if money is good then just build it before it blows.


Hopefully some folks that have been through it can chime in and guide us

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