Hi folks, here's my situation. I'm reviving my C4 project I never finished, but need a little help figuring out what direction to go. I was a bit more impulsive and didn't fully think things through so now I'd like to get it back up and running smoothly since the last time I drove it, it felt very rough and I know things are very mismatched. So here's what I have ...
Stock LT1 block / heads / cam
ported LT4 intake
headers / no resonator / no mufflers
Superchip / tune
700R4
3600 stall converter
Dana 36 / 3.54 gear
I'd like to drive this regularly on the street so please correct me but here's what i'm thinking. The converter likely needs to go, keep the intake, improve the heads / cam combo, mufflers, tune.
I'm stuck on what to do with the heads and cam. I'd like to keep the head cost at around $2k, so...
Option 1: having a local shop do the port and polish, everything I've found still points to the ported LT1s performing very well, but I would still need all new hardware.
Option 2: something like these from AFR
AFR 210cc LT4 Heads I'm leaning this way since these are assembled and ported.
As far as the cam I have no idea yet but I'd like it to get closer to 400hp
Thoughts?
Before putting out the money for higher cost parts I'd suggest baseline what you do have and assure engine is functioning and performing to it's
best ability ?
What year is the C4
How many miles on the power and drivetrains
What changes have been made as to age as to fuel injectors, MAF, MAP, O2 sensors, etc
Have you checked the fuel rail pressure, is it working correctly to about 43 PSI at low end and a bit higher at WOT
What elevation and type of fuel used
Not sure the convertor has to be changed or if the tune you have is set for that stall rate
Does engine have a MAF or not then it is speed density tuned and maybe wrong for elevation, weather, fuel type I'd suggest using a OBD-I scanner is used to do testruns collecting feedback sensor data, if not having a laptop scanner I can suggest one
that is cheap in cost but does record while driving which later can be analyzed, if you cannot do that I sell a service to analyze that data
and give you a report and maybe suggest changes needed
Assure the tune you have is correct for the makeup of engine and tranny. I asked about model year as that tells me if engine has a ECM
which has calibration in a E-prom or uses a PCM and flash memory (94-96)
The scanner data would point to if tune is correct or not
I do custom tuning and could be done either via emails or by mail
If keeping stock CAM you might consider with a higher ratio rockers, could be the stock fuel injectors are a bit too small ( why elevation matters)
and/or they need cleaning or using a adjustable fuel regulator to change the rail pressure up a bit would cause the injectors to flow more
What coolant T-stat using, maybe best going with like a 170 deg one and then tuning fans to come on sooner
