Motor is done and I get my car back this morning!

[jmichalicek]

Wooohooo! My motor has been rebuilt, gears have been installed, and the tune is done. I get my car back this morning. Here are a few numbers for comparison.

Orignal dyno run back in '00 or '01 (I forgot already and I'm not digging the sheet out again): 272tq/255hp on a dynojet. This was done by the previous owner of the car to verify the fix had been done. The dyno operator said the hp was low due to not having some sensor hooked up... I've forgotten what specifically, it's been years.

The engine has been rebuilt with ModMax crank, ModMax rods, Mahle flat top pistons (I won't have the money for FI any time soon, so I'm doing what I can), 4.10:1 gears. Other than that it's bone stock down to the exhaust and stock air box.

Pre-tune: 275tq/264HP
Post tune with SCT XCal3 custom tune: 292tq/289hp

'm not sure if these were on a dynojet or mustang dyno. I'll find out this morning. The shop did not have a dyno at all when I brought the car in, but has been supposed to get a mustang dyno and they were remodeling, so I'm hoping (but not expecting) that those new numbers were on a mustang dyno.

 

[99MystiC]

Congrats!

 

[Chris's Cobra]

now put some nitrous on that thing!

 

[jmichalicek]

Alright, back from the shop. Too much traffic and wet roads for me to punch it. Those numbers are from a dynojet, but still, not bad at all. I'll upload graphs when I can get them scanned.

I probably won't spray it. I have yet to make it to a track with this thing and it's illegal to even have hooked up but not actively being used where I am. I know I'd be unlikely to get caught, but still, not really worth the risk to me.

I need to check to see if he corrected the speedo for the new gear. The whole way home my speedo said I was doing 80, but cars were flying by me.

update: yep. definitely didn't get the speedo calibrated, so hopefully I can stop by the shop today and get that taken care of. My wife confirmed that we were going 60-65 according to her car and my RPM calculations also put me closer to 65 mph.

 

[006]

Not bad numbers for bone stock, but why have it tuned if you have ZERO mods?

Now after getting aclimatized to the power, you'll want to open up the exhaust a little and maybe also get more air going in, and a pulley or whatnot, and then you'll have to bear additional costs to re-tune.

:shrug:

 

[jmichalicek]

Needed the tuner for the speedo calibration (which didn't get done , lol) anyway. Plus I know the way I spend money when it comes to modding the car... I generally don't, as you can tell. I have a hell of a time justifying it when it comes down to it compared to fixing something around the house or whatever. So with that in mind, I figured wtf, I'm blowing a ton of money right now anyway, so I might as well get what extra performance I can out of it. Even if I do end up doing something that causes me to need it re-tuned, it'll be a at least a year, possibly longer.

I can't complain too much. Many people with Cobras have spent as much for smaller gains. My tune was $525 including the cost of the tuner that I kept.

 

[01yellercobra]

What compression did you end up at?

 

[jmichalicek]

What compression did you end up at?

I'll probably call the machine shop that put it together to try to get a more exact number next week. It should be right in the 10.1-10.3:1 range, though, I think. The pistons are 11.5:1 with a 46cc chamber and I believe the dish on the stock pistons is pretty small, so with that, a thin head gasket, some some rough estimates that sounds about right.