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600Whp + Stock Tcm...bad Idea?

29 posts in this topic

Car keeps hitting limp mode..is it because of a stock TCM?  

I have a Stage 3 Paramount Transmission, Stroked 5.7 to a 393, Vortech V3 pushing 10-12psi.

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Let me be more specific, sorry about that....

 

Stage 3 Paramount Transmission...shifting at 6400rpm or less but still hitting limp mode.  Getting limp mode when WOT from 0 and sometimes on downshifts.

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Still on stock tcm with 630+whp, no issues with limp.

 

SHR built trans.

 

You have it set to shift at 6400, or is the shift completed at 6400? Whats the log say? Two different things, especially with just a VB on a stock trans.

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Also, the max rpm in the trans depends on if you have a 5.7 or 6.1 or 6.4TCM. 6700 is the SRT limit. I think the 5.7 TCM liit is around 6200.

 

J

I have a 5.7 TCM however I've shifted at 6400rpm before my build.  Now that my build is done, I'm getting issues with limp mode.  My build consists of 393 stroked 5.7, Paramount Stage 3 Transmission, Vortech V3 10-12psi.

 

 

Still on stock tcm with 630+whp, no issues with limp.

 

SHR built trans.

 

You have it set to shift at 6400, or is the shift completed at 6400? Whats the log say? Two different things, especially with just a VB on a stock trans.

 

Mike at OST is the one who built my car and he's working on the tune...He mentioned that he doesnt know anyone with the stock tcm above 600rwhp.

 

Any suggestions on what to do?  Do I need a new TCM or is it all in the tune?

Also, when I do go in limp mode, the check engine light comes on and the code is incorrect gear ratio.  I never changed my gear ratio, it's 3.06 and when I look at the tune, 3.06 is selected....

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Is it gear specific? Incorrect gear ratio could be detected in first, second, third, 4th or 5th gear, as well as the final drive. What is the code specifically? That should tell you. Your issue seems to be related to gear ratio. If the rear gear is correct, what is the tire diameter? That can also affect gear calculations in the TCM.

 

Remember, just because you are targeting 6400rpm shifts doesn't mean its actually shifting at 6400. Higher hp applications can push past the desired shift point and put you into the trans over rev limit in the tcm, especially with stock TCMs. I usually tell people with stock tcms to leave the shift points stock and don't raise them with the trinity.

 

J

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That is exactly what my car did. Turns out the trans was slipping a little on the 2-3 shift. In went an SHR trans, and the problem was gone,

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Is it gear specific? Incorrect gear ratio could be detected in first, second, third, 4th or 5th gear, as well as the final drive. What is the code specifically? That should tell you. Your issue seems to be related to gear ratio. If the rear gear is correct, what is the tire diameter? That can also affect gear calculations in the TCM.

 

Remember, just because you are targeting 6400rpm shifts doesn't mean its actually shifting at 6400. Higher hp applications can push past the desired shift point and put you into the trans over rev limit in the tcm, especially with stock TCMs. I usually tell people with stock tcms to leave the shift points stock and don't raise them with the trinity.

 

J

 

P0730 is the code.

 

I changed my shift points to stock but still no luck :/  The tire diameter is 275/40/20 in the rear.

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Happens on down shift also? 

 

At the very least, sounds like you need a 6.1 tcm if you cant get the 5.7 past 6200rpm's. 

 

Built trans should also be on your soon to get list. 

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There are many people running stock TCM with over 600rwhp. I have been above that for the last 3 years and 60,000 miles.

 

Granted I am running a built transmission, but I am running stock tcm and diff.

 

Has it been that way only on that tune? If you had another tune that was running ok, try that one to see if it replicates the issue. (and if it wont screw up anything else in your car) If your other tune has no issues, then perhaps that will open up a fix in Mike's tune for you.

 

You could try removing the tune from the PCM, back to stock and then reload fresh just to check if there was a glitch.

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Happens on down shift also? 

 

At the very least, sounds like you need a 6.1 tcm if you cant get the 5.7 past 6200rpm's. 

 

Built trans should also be on your soon to get list. 

 

Has happened on down shift yes..  I can get the 5.7 above 6200rpms..I've done it before the build..have gotten it up to 6400rpms before problem FREE.

 

I HAVE a built trans.....STAGE 3 Paramount Transmission.

 

 

There are many people running stock TCM with over 600rwhp. I have been above that for the last 3 years and 60,000 miles.

 

Granted I am running a built transmission, but I am running stock tcm and diff.

 

Has it been that way only on that tune? If you had another tune that was running ok, try that one to see if it replicates the issue. (and if it wont screw up anything else in your car) If your other tune has no issues, then perhaps that will open up a fix in Mike's tune for you.

 

You could try removing the tune from the PCM, back to stock and then reload fresh just to check if there was a glitch.

 

I am running a BUILT transmission too (Stage 3 Paramount Transmission) and am running stock TCM and Diff.

 

I don't have any tune that the limp mode was good.  Mike sent me the car back and I've been having limp mode issue ever since, he had the issue a few times too with the same code saying incorrect gear ratio.

 

I will try going to stock and then reloading the tune to see if that fixes any glitches that could've happened...

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So looks like its not shifting fast enough therefore I'm hitting the rev limiter and going into limp mode. Why does it lag so much to shift? How do I fix it?

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Getting a custome flashed TCM with raised limits is probably your best bet.

 

At the very least, a stock 6.1 tcm with stock shift points shouldn't see limp if your Trans is healthy.

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    Try shifting at 6200 instead of 6400. I have pretty much the same set up as you motor & transmission. I do have the MTCM & my transmission has very firm  up & down shifts. I don't know anything about your transmission but it sounds like it is getting lazy. Maybe time for a refresh from Bill. I shift at 6200 to keep from over spinning the V3 pump. I am making 13,2-13.5 lbs of boost shifting at 6200. If I remember the MTCM  shift limit is 6700. You are probably hitting the limit on your stock TCM. if you are shifting that high. I know I had to get AJ to reprogram my stock TCM with my stock transmission when I left Arrington when they put my motor in but that was 5 years ago. Mike does the tuning on my car also. You are in good hands with him.

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If you are getting incorrect gear ratio codes the trans is slipping internally or the valve body might need to be cleaned.....which means the clutches are shedding enough material that they fouled the input speed sensor. Try changing the fluid and drop the valve body. Clean the valve body off with brake kleen. If it still does it the trans is hurt.

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In my experience with your issue it was a valve body issue.   Try what Erik suggested...  Maybe ask bill for a different valve body.  BTW I ran 10.0s for a long time with Bills trans and stock TCM   no issues.  Matter of fact the trans is still being used 5 yrs later  :)

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    Try shifting at 6200 instead of 6400. I have pretty much the same set up as you motor & transmission. I do have the MTCM & my transmission has very firm  up & down shifts. I don't know anything about your transmission but it sounds like it is getting lazy. Maybe time for a refresh from Bill. I shift at 6200 to keep from over spinning the V3 pump. I am making 13,2-13.5 lbs of boost shifting at 6200. If I remember the MTCM  shift limit is 6700. You are probably hitting the limit on your stock TCM. if you are shifting that high. I know I had to get AJ to reprogram my stock TCM with my stock transmission when I left Arrington when they put my motor in but that was 5 years ago. Mike does the tuning on my car also. You are in good hands with him.

 

The transmission is 2 months old and this has been my 3rd time driving it.  I don't think it's the transmission.  

 

If you are getting incorrect gear ratio codes the trans is slipping internally or the valve body might need to be cleaned.....which means the clutches are shedding enough material that they fouled the input speed sensor. Try changing the fluid and drop the valve body. Clean the valve body off with brake kleen. If it still does it the trans is hurt.

 

Same per above, transmission is brand new..I called Bill and he advised to get the Paramount TCM...going to install that tomorrow and see if it fixes it.

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Why is that? Had to pay for it..

cause id be pissed if I shelled out for a "try this".....especially since I know it's not a tcm issue. I only do this for a living. Just cause the trans is 2 months old means nothing. Clutches in general will shed material. Couple bad tune revisions will slip the shifts and shed material.....the trans just breaking in will shed material. Know where it goes....the magnetic sensor on the top of the valve body. Boom limp as soon as you hammer it. Does the converter lock right? That will do it too. Is the fluid level correct? A qt low will do it too. TCM? Not so much.

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Makes a whole lot of sense as to why you are not getting an over rev code, which is what you should get if you are blowing past TCM shift points and screaming toward over rev.

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