No reprograming needed?

[MH2Lmaker]

I'm about to have 3.42's and a 2800 stall TC installed ( I now have 2.73 and stock TC) by a certified Corvette Tech. He told me I would not need to be reprogramed or tuned. This seems to be contrary to what I read on this forum. What is the majority concensus?

[Mike Mercury]

What is the majority concensus?

do you want opinion, or fact ?

[MH2Lmaker]

I'm sure not everybodys opinions are the same but, from what I read on different topics on these forums niether are everybodys "facts". I'm sure if I installed nothing and had my vette reprogrammed it would run better but It runs pretty good now. What I was wanting to know is will it run worse without a reprogram or tune after the 3.42s and TC are installed. The person who will install is a Certified Corvette Technician. Is he not telling me the "facts"?

[Mike Mercury]

when advancing past the 2.73 with any other ratio (even the 3.15) two things will happen:

1. During WOT, you will hit the rev limiter before the PCM tells the tranny to shift. For example; you will stay in first gear with the RPM of the engine bouncing high and low... until you let off the gas a bit (then it'll shift into second) . It's even more evident with the A4 gear selector in "3". The WOT shift points will need to be altered via re-programing to keep you from hitting the rev limiter during WOT.

2. You will eventually throw the P1870 error code... and then eventually lite the Check Engine lamp. The P1870 error code states that the tranny and/or TC is slipping much more than normal (which isn't the case)... but in this instance the PCM is fooled into believeing the TC/tranny is slipping more because of the increased RPM when compared to the MPH. The TCC Slip table needs to be adjusted via a reprogram - so it now knows the newer-higher RPM at a given MPH is normal - and not a (false) tranny malfunction.

.





[Modified by Mike Mercury, 6:35 PM 7/1/2004]

[gojo]

The Tech will do a nice, clean and neat job of installation. As Mike points out you will need reprogramming. I guarantee you will go into limp mode if you don't.

[0rion]