Losing HP due to trans???

[jjjferro]

Long story short:
Built engine (all forged internals), built 5r55s (yea I know but didn't have cash to go any other route and trans was broke at the time), also went from a P1sc to a D1sc. Just got all remaining upgrades done and as per Tuner, cars making 100 less rwhp than expected.

Second gear started slipping on the dyno and car made even less power when converter was locked. Took Mustang back to trans shop (trans is warrantied) to fix and look at why we are losing power. Trans shop just told me band for second gear needed to be replaced (something about he wasn't able to test drive when originally put in) and that could have been the issue. Said everything else looked like new and will freshen it all up. To me he seems to be downplaying everything.

There's no issue will engine cause I had a cylinder leak down test done to make sure that wasn't the cause (also so Trans Guy can't say it's not his product). Engine is strong, no issue at all.

Anyone have some insight on what they think? Past experiences? Has to be trans related correct?

 

[stkjock]

define "100 less rwhp than expected"

compared to what?

same model trans as previously in the car?

 

[jjjferro]

Yes. Related to a built 3v auto, D1, and rebuilt trans from same company making close to 700 rwhp. Ran 10.2 in the qtr mile.

 

[stkjock]

comparing dyno #s between cars is a sticky situation, the car you're comparing too, same dyno and fuel?


you had a 5r55 in the car previously?

 

[jjjferro]

Yea same Tuner, shop, and 93*. Stock 5r55s snapped input shaft at track last year.