BayouVette

I arleady had my car tune for my current mods with the LS1 edit. I will after a get a few more things in get it tunned again. My question is does the jump from the 3.15 to the 3.42 require a tune to take advantage of the change..

blktie8

NO!
http://mikemercury.home.att.net/342.htm


[Modified by blktie8, 10:36 PM 7/26/2003]

thefly

yes cause the speedometer would be off. auto don't measure speed like manual do off the output shaft.

ToplessTexan

BayouVette, yes you want to reprogram. There's plenty of threads on the topic to search that have good info to digest.

thefly, the speedo works in exactly the same way, both auto and stick. The (gear change) reprogramming addresses shift points, not the speedo. (Tire heights are a whole different game.)

Mike Mercury

absolutely and completely false.

------------------

BayouVette probably does not "require" a reprog. But, should he? probably yes. :yesnod: get the WOT shift points more in line with the power curve of the engine.




[Modified by Mike Mercury, 12:18 PM 7/28/2003]

BayouVette

my current settings are

Rev limiter 6500.. ( i never take it this high)
Shifts at 6100

this is why I don't see why programming would help

RWTD

No, you do not have to have this done for a 3.42 from a 3.15 change, so long as you aren't overreving, or prematurely banging the rev limiter. As for shift points, 6100 is slightly high, and I'd prefer a 6000 shift point. If re-programming is free, then go for it.

Sincerely...

ToplessTexan

I don't think 6100 is too high, particularly if you're trying to take advantage of your converter's shift extension. I'd definitely prefer reving past the power peak (particularly if it's flat rather than falling off, and assuming the valve train can take it) versus reving just to it and falling farther down the power curve on a shift. (I.e. don't short shift.) If you're happy with it and as James mentioned not hanging up on limiters through shifts, don't sweat it. I am always a little skeptical of being able to run the 3.15 to 3.42 swap w/o programming though.

Mike Mercury

there is no consistancy from year to year.

bgood

:iagree: I had to go with programming to scale correctly from 3:15 to 3:42. After my gear upgrade I was getting the P1870 code which was corrected with LS1 Edit. Shift point tuning is not required, but if you are having to scale for the gear change you might as well fine tune the shift points to an optimal setting of your choice.

Seth

I used a Hypertech to adjust the shift points for the gear change. I originally had 2.73s and my car would hit the rev limiter on WOT shifts after the swap. Shifiting is fine now but on the highway I get the P1870 code like many others. Apparantly LS1 Edit is my only option for getting rid of this annoyance.

Seth