Once you get a dyno tune is there a chance that it will come out of adjustment by racing it. Another words how often do you have to tune your car once it is done the first time. And can a good tune tell you where your power loss is coming from by reading what the car is doing through the computer?

 

Once tuned the tune is good till you do more mods, if power begins to fall off it is a mainanance issue with plugs wires, dirty injectors or something like that, the computer does not lose adjustment.

 

Tuning can't tell you where your power loss is coming from unless it's timing or fuel related.

 

Ok is this fuel related......i got a dyno tune....base line pulled the Air/fuel ratio went from 14.7 at 1700 RPM to 12.5 at 6000 RPM and the tuned run it stayed about the same. Does this say anything about if corrected the fuel needs throughout the run.

 

Sounds like the tune is decent but a bit lean in the lower RPM.. about what RPM does the AFR reach at least 13.0? Max power is made around 6000 rpm and thats where the AFR is pretty close so Id be looking into rocker adjustment or something else.

 

OK...13.0 air fuel ratio is met around 5000 PRM and yes max power is met at 6000 RPM....i will be adjusting the rockers as soon as i feel as though the engine shop will not make good on there adjustments..I'll try adjusting the rockers that are on the car now but...while on the topic...i had 1.6's on the car before the re-build but had a lot of problems (the shop did) hitting the valve covers.....did you ever hear of the Melrose T-Top international selling taller valave covers? Or any body for that matter because i would like to put the 1.6's back on here.....right now they are only the cc 1.5's. And in changing the rr do i need the change anything else in the process.

Thanks again for the help....

 

The pro mag rockers from comp either 1.5 or 1.6 will hit the valve covers unless the supports are cut out of them to allow clearance for the main body of the RR. But after doing that you wont have any problems... its what most guys do to resolve that issue.

 

I just bent the supports a little and the comp pro mag 1.6s fit fine. Have you checked any of the other things i told you too. Knock retard and fuel pressure? Im not sure if you can tell if the fuel pump is going out by the af ratio but it doesn't hurt to check the fuel pressure. Check all the stupid little stuff. Adjust the rockers yourself with the car running. Loosen one untill you hear it clatter and then tighten it untill it just stops, then set your pre-load to what ever you lifters are.