Best way to shut down your race car after a pass
05-20-2009, 07:46 AM
#1
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Location: Clawson, Mi.
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Best way to shut down your race car after a pass
Hey all, recently I have heard some things concerning how or what is the best way to kill your engine after passing the traps if a plug reading is desired, and I usually let the engine help slow me down along with my brakes but what routine do you guys do for a plug reading?
I have heard that, with a TH400, and maybe a glide as well, that you should NOT shut down the engine in nuetral as the trans pump no longer pumps oil to the trans in nuetral and you can damage the trans, is there any truth to this????? I have also heard that, if your going to do a plug reading and you need to kill the engine, to do it in gear!!!! won't this cause a problem also, although I don't know what problem it will or could cause?????
Any help is appreciated as always. and good luck this year racing guys/gals.
John
The Elkyman
I have heard that, with a TH400, and maybe a glide as well, that you should NOT shut down the engine in nuetral as the trans pump no longer pumps oil to the trans in nuetral and you can damage the trans, is there any truth to this????? I have also heard that, if your going to do a plug reading and you need to kill the engine, to do it in gear!!!! won't this cause a problem also, although I don't know what problem it will or could cause?????
Any help is appreciated as always. and good luck this year racing guys/gals.
John
The Elkyman
05-20-2009, 08:22 AM
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Info found
Ok guys/gals, I just called my trans guy and here is what HE had to say about the two transmissions.
A TH400, can NEVER be put into nuetral and the engine cut off as what happens is, now the engine is not controlling the drum in the case at 7000 rpm's (as an example engine rpm), and since the driveshaft is now spinning the drum at 2.2 times the speed of the engine that was, at say 7000 rpm's, the drum is now spinning at over 15,000 rpm's and BOOM, there goes your trans.
The powerglide is able to handle this type of shutdown as the internal parts connection are a little different so it is ok to jam your glide in nuetral, and kill the engie to do plug reading at the turnoff of the strip, whoo, got me to thinkin there for a minute :?
Just some info that may help others out later if they don't know what or how to do this that want to read plugs for tuning. Now I know the rest of the story, Paul Harvey, Good Day!!!!
Elkyman
John
A TH400, can NEVER be put into nuetral and the engine cut off as what happens is, now the engine is not controlling the drum in the case at 7000 rpm's (as an example engine rpm), and since the driveshaft is now spinning the drum at 2.2 times the speed of the engine that was, at say 7000 rpm's, the drum is now spinning at over 15,000 rpm's and BOOM, there goes your trans.
The powerglide is able to handle this type of shutdown as the internal parts connection are a little different so it is ok to jam your glide in nuetral, and kill the engie to do plug reading at the turnoff of the strip, whoo, got me to thinkin there for a minute :?
Just some info that may help others out later if they don't know what or how to do this that want to read plugs for tuning. Now I know the rest of the story, Paul Harvey, Good Day!!!!
Elkyman
John
07-17-2009, 07:07 PM
#6
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going into neutral or worse
be careful elkyman neutral dont live very far away from reverse. i know 2 racers who almost killed themselves (and their cars) by slipping past neutral into reverse. its not hard to do unless you have a safety valve body that wont permit this to happen. i have a hyperflow in my glide and it can go intyo reverse even if i try chevy art
07-26-2009, 09:59 AM
#8
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Originally Posted by Rigsby
Would this apply the same to the TH350 (like the 400??)
Doing burnouts in 1-2 can cause low clutch sprag failure, with catastrophic failure of the drum.
Chrysler 727
Turbo 400
07-26-2009, 06:22 PM
#9
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Originally Posted by OneBadGMC
ANY 3 speed transmission should never be put in neutral, and should only be doing burnouts in 2nd and 3rd, never first. If enough HP is on tap, do high gear burnouts only.
Doing burnouts in 1-2 can cause low clutch sprag failure, with catastrophic failure of the drum.
This is very good to know. Is it the 1-2 shift that cause the low sprag to fail? Is it ok to leave it in 1st just to clean the tires off?
07-26-2009, 08:34 PM
#10
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Originally Posted by kicker91laser
Originally Posted by OneBadGMC
ANY 3 speed transmission should never be put in neutral, and should only be doing burnouts in 2nd and 3rd, never first. If enough HP is on tap, do high gear burnouts only.
Doing burnouts in 1-2 can cause low clutch sprag failure, with catastrophic failure of the drum.
This is very good to know. Is it the 1-2 shift that cause the low sprag to fail? Is it ok to leave it in 1st just to clean the tires off?
We had a huge discussion about it on Yellowbullet a few months back.
I dont think cleaning the tires off ever came up, but, as in post #7 from that thread...
The low roller clutch is designed to work under load & for this reason it is highly recomended that you do not do burn outs or hard peddle the car while in first gear. The loading & unloading of the low roller clutch causes the rollers to slam against the springs & flatten them. If the low roller fails under load it will send the dirct drum to 3.25 + times engine speed, usally very bad when there is a cast drum involved.
