Converting to a T400, couple of questions
Converting to a T400, couple of questions I am new to the A3 scene and have a couple of questions.
I have read through all of the FAQ’s and sticky and are quite confused.
Current mods:
Performance:
-Lid
-Ported throttle body
-QTP Longtubes
-Tru Dual exhaust running out the back
-Custom Diablo tune
-150 shot of nitrous
Suspension (100% UMI):
-Boxed LCA’s
-Relocated LCA’s
-Double adjustable Torque arm (with frame mount instead of tranny)
-Ford 9in w/ 4.11’s
-Sub frame connecters
-Comp 50/50’s in the rear
-QA1 12 way adjustable up front with 300lb springs
-Welds wrapped with 325 (28in tire)
- 3.5in aluminum DS
Car ran a best of 11.9’s @ 117 on motor full weight, have not ran it on spray yet since it was just installed.
As for near future plans for the car I plan on keeping it a nitrous car, eventually do heads, cam, etc. The car is not daily driven, but will be raced a lot on the street, therefore drivability is not an issue, along as it can hook on the street and the track.
As for my following tranny questions, looking to see what you guys would do if you were in my shoes:
- What RPM stall ( want to stick with YANK)
- Would you use a trans brake?
- Case lengths (completely lost in this part, is there a setup where I can retrain factory mounting for the crossmember?)
Anything else I did not mention you guy would do?
Thanks in advance,
Kev D
I have read through all of the FAQ’s and sticky and are quite confused.
Current mods:
Performance:
-Lid
-Ported throttle body
-QTP Longtubes
-Tru Dual exhaust running out the back
-Custom Diablo tune
-150 shot of nitrous
Suspension (100% UMI):
-Boxed LCA’s
-Relocated LCA’s
-Double adjustable Torque arm (with frame mount instead of tranny)
-Ford 9in w/ 4.11’s
-Sub frame connecters
-Comp 50/50’s in the rear
-QA1 12 way adjustable up front with 300lb springs
-Welds wrapped with 325 (28in tire)
- 3.5in aluminum DS
Car ran a best of 11.9’s @ 117 on motor full weight, have not ran it on spray yet since it was just installed.
As for near future plans for the car I plan on keeping it a nitrous car, eventually do heads, cam, etc. The car is not daily driven, but will be raced a lot on the street, therefore drivability is not an issue, along as it can hook on the street and the track.
As for my following tranny questions, looking to see what you guys would do if you were in my shoes:
- What RPM stall ( want to stick with YANK)
- Would you use a trans brake?
- Case lengths (completely lost in this part, is there a setup where I can retrain factory mounting for the crossmember?)
Anything else I did not mention you guy would do?
Thanks in advance,
Kev D
Last edited by KevsfastZ; May 29, 2008 at 11:07 PM.
no front suspension?
4k stall would work well with your setup...
transbrake will be nice for the track, but kinda pointless for the street unless you can make that sucker hook...
i was able to use my factory M6 trans crossmember with my TH400 swap...all i had to do was slot the hole for the trans mount bolta bit and it lines up perfect....
4k stall would work well with your setup...
transbrake will be nice for the track, but kinda pointless for the street unless you can make that sucker hook...
i was able to use my factory M6 trans crossmember with my TH400 swap...all i had to do was slot the hole for the trans mount bolta bit and it lines up perfect....
no front suspension?
4k stall would work well with your setup...
transbrake will be nice for the track, but kinda pointless for the street unless you can make that sucker hook...
i was able to use my factory M6 trans crossmember with my TH400 swap...all i had to do was slot the hole for the trans mount bolta bit and it lines up perfect....
4k stall would work well with your setup...
transbrake will be nice for the track, but kinda pointless for the street unless you can make that sucker hook...
i was able to use my factory M6 trans crossmember with my TH400 swap...all i had to do was slot the hole for the trans mount bolta bit and it lines up perfect....
They make two different tailshaft lengths, the short one needs a longer DS.
no front suspension?
4k stall would work well with your setup...
transbrake will be nice for the track, but kinda pointless for the street unless you can make that sucker hook...
i was able to use my factory M6 trans crossmember with my TH400 swap...all i had to do was slot the hole for the trans mount bolta bit and it lines up perfect....
4k stall would work well with your setup...
transbrake will be nice for the track, but kinda pointless for the street unless you can make that sucker hook...
i was able to use my factory M6 trans crossmember with my TH400 swap...all i had to do was slot the hole for the trans mount bolta bit and it lines up perfect....
Sorry for the delay, I just came back from vacation.
The car does have front suspension, QA1 12 way adj with 300lb springs.
As for the M6 crossmember, I am using a UMI CM with torque arm mounting point, I would imagine I could do the same thing.
As I said before, it will be a track car, but will also be used for "legal" street racing often.
Kev D
I'd get the brake just for the track. Wire it so the kit comes on as soon as you let off the button...It'll be sick with those 4.11 gears.
3800-4000 stall...Again, on spray it'll be sick. Make sure you tell Yank everything you can about the setup so they can build the converter right and keep it efficient.
You'll need more gear on spray with that 4.11 I think.
3800-4000 stall...Again, on spray it'll be sick. Make sure you tell Yank everything you can about the setup so they can build the converter right and keep it efficient.
You'll need more gear on spray with that 4.11 I think.
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Launching!
Joined: Jan 2003
Posts: 218
Likes: 0
From: NV
I'd get the brake just for the track. Wire it so the kit comes on as soon as you let off the button...It'll be sick with those 4.11 gears.
3800-4000 stall...Again, on spray it'll be sick. Make sure you tell Yank everything you can about the setup so they can build the converter right and keep it efficient.
You'll need more gear on spray with that 4.11 I think.
3800-4000 stall...Again, on spray it'll be sick. Make sure you tell Yank everything you can about the setup so they can build the converter right and keep it efficient.
You'll need more gear on spray with that 4.11 I think.
As for wiring the kit to come on as soon as he lets off the transbrake, I don't think that's a good idea because he might not be over 3000 RPMs sometime when he lets off and it is armed. Stick with the WOT switch and set things up not to come on below 3000 RPM minumum. Safer IMHO.
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Verdad Gallardo I'd get the brake just for the track. Wire it so the kit comes on as soon as you let off the button...It'll be sick with those 4.11 gears.
3800-4000 stall...Again, on spray it'll be sick. Make sure you tell Yank everything you can about the setup so they can build the converter right and keep it efficient.
You'll need more gear on spray with that 4.11 I think.
3800-4000 stall...Again, on spray it'll be sick. Make sure you tell Yank everything you can about the setup so they can build the converter right and keep it efficient.
You'll need more gear on spray with that 4.11 I think.
Kev D
Short one is stronger and more common. You should get a new HD DS anyway. Also, if you want the speedo, you can get a tailshaft to work off the stock PCM wiring, just need to change a few perameters in it.
Launching!
Joined: Jan 2003
Posts: 218
Likes: 0
From: NV
On a 28" tire, 4:11s should be okay unless you're trapping over 140 mph.
I think 142 MPH puts you at 7000 RPM with 4:11 gears on a 28" tire.
I have my calculations for my 28" tire and 3.70 gears, at 140 mph trap speed I will only be at 6216 RPM. You will have to have some idea what you will be trapping and run the numbers through a calculator.
Like this one:
http://murray.faithweb.com/formulas.htm#find_rpm
Last edited by ChevyGoldfinger; Jun 9, 2008 at 03:20 AM.
You're not going to be concerned with the gear ratios in the tranny except for 3rd gear. You will be in 3rd at the big end and it will be (1 to 1).
On a 28" tire, 4:11s should be okay unless you're trapping over 140 mph.
I think 142 MPH puts you at 7000 RPM with 4:11 gears on a 28" tire.
I have my calculations for my 28" tire and 3.70 gears, at 140 mph trap speed I will only be at 6216 RPM. You will have to have some idea what you will be trapping and run the numbers through a calculator.
Like this one:
http://murray.faithweb.com/formulas.htm#find_rpm
On a 28" tire, 4:11s should be okay unless you're trapping over 140 mph.
I think 142 MPH puts you at 7000 RPM with 4:11 gears on a 28" tire.
I have my calculations for my 28" tire and 3.70 gears, at 140 mph trap speed I will only be at 6216 RPM. You will have to have some idea what you will be trapping and run the numbers through a calculator.
Like this one:
http://murray.faithweb.com/formulas.htm#find_rpm
does the OP have a lock up converter? If he doesn't his numbers will be different.
Launching!
Joined: Jan 2003
Posts: 218
Likes: 0
From: NV
Let me guess. . . other person?
As for lock up converters in the TH400 trans, I have never heard of one that locks up. Mine does not.
Educate us on why the numbers will be different at 1 to 1 in high gear. I am pretty sure you refer to the vert continuing to spin up in 3rd gear because of the unlocked vert. How would you calculate the RPM at a given trap speed accurately then?
Last edited by ChevyGoldfinger; Aug 25, 2008 at 05:04 AM.
Launching!
Joined: Jan 2003
Posts: 218
Likes: 0
From: NV
Not sure what you mean by OP. (not a text messager here)
Let me guess. . . other person?
As for lock up converters in the TH400 trans, I have never heard of one that locks up. Mine does not.
Educate us on why the numbers will be different at 1 to 1 in high gear. I am pretty sure you refer to the vert continuing to spin up in 3rd gear because of the unlocked vert. How would you calculate the RPM at a given trap speed accurately then?
Let me guess. . . other person?
As for lock up converters in the TH400 trans, I have never heard of one that locks up. Mine does not.
Educate us on why the numbers will be different at 1 to 1 in high gear. I am pretty sure you refer to the vert continuing to spin up in 3rd gear because of the unlocked vert. How would you calculate the RPM at a given trap speed accurately then?
Yes they make them. I thought I had read somewhere you had one. I guess I must have been thinking of the wrong person.
Well I'd calculate the RPM at a certain speed using 1:1 as my ratio from the formula or a calculator. Then I'd go out in the car and go WOT, when it hits that speed record the RPM. Subtract the two and there's the converter slippage. I'd do it across the board using a variety of speeds to make sure my number was accurate across the RPM range as well and to note any changes in slippage at different ends of the band. Last time I did it the difference was neglible from those points.
At the track last time with my 3000 stall speed converter I was about right at 125 mph at 6800 rpm on a 28" tire and 3.73 gears. I was going off the stock tach so it might not be the most accurate tho.
Sounds like a fair amount of slip if that RPM is correct. Using mine as a reference, I had a 4800 stall, 4.10 gears, 28" tires and trapped 126 at 6400 RPM. I would data log a run and see what the RPM is so you get a more accurate read, don't trust that stock tach to much. You should be closer to 145+ mph at 6800 RPM with your gears and tires.