Hey Guys
i have been lurking here on the boards for about a year reading and learning everything i could and now i have a question
background is we race a local asphalt oval in basically a stock class and its a 1995 cavalier 2.2
so i bought the car used at the end of last season rebuilt the bottom end over the winter .. just new bearings, rings and a hone ... block was in good shape surprisingly
then i did the heads with the comp cams beehive springs, a set of Manley push rods and the sbc 1.6 ratio rockers
we have not touched the injectors or the throttle body... no shaving or decking
now comes the question part ... the computer is the stock untunable 95 computer ... after the rocker upgrade am i looking at a lean condition that might have robbed some power from me?
the wife is the driver and her first race was yesterday she ran fine and finished but she was definitely slow (first time jitters and all) but i have watched this car finish 6th last season before i bought it so i know its capable of more than that
but for arguments sake lets remove the nut behind the wheel as the issue, and get to the questions
#1 should i not have done the rocker upgrade without a tunable ecm?
#2 how bad is an ecm swap to like a 97 ecm ... do i need the whole wireing harness or can i just do an ecm swap .... any other recommendations gladly welcomed
#3 any recommendations for the current setup?
#4 thoughts on rechiping the current ecu ... i do know someone that can program a chip for me that i can install in the ecu with a memcal adaptor (not a bs ebay chip) for under $200
i do have a second 2.2 block i'm going to build for next season with the rocker upgrade and the piston/compression upgrades ... but i guess tuning is my real issue ... i would have no issue buying HPT if i could get to a point where i could use it
any recomendations welcome
and big thanks to madjack and OHV notec i learned so much from you two
Are both blocks the pre 98' year models? If so when you do the harness swap there will be a few more sensors to deal with... not totally for sure how many if any engine wise but you will for sure will have a second o2 sensor.I recently did a high comp build that acted like it ran lean, jumpy acceleration and poor response... Mind you I was in the same boat as you.... untune-able ecu (95') but none of the valvetrane work.... doing that currently.. You can and should get the ecu socketed and re-tuned. its just easier.... as long as you are done making changes to you build, otherwise its more dough... kinda try and make it a one and done type of thing.... I did make a mistake on that last build that hindered its capabilities and probably caused the breakdown.... Between the 2 engine year ranges 95-97, 98-up the pushrods are a different length.. 7.458 95-97 and 7.515 for 98up. I don't know if you are running a stock cam or what but Im betting you may want to check pushrod lengths... or if there was a sudden loss of power... tear it down and see if there was a broken piston in one of the cylinders like what I found...
Let me know if this helps and keep us updated!
