Johnie_West

I need some input really bad. The last time I dynoed my 2001 TA was 3 years ago. It made 383.4 rwhp and 436 max torque. The car was parked for at least 1 year without being started. I changed the converter out from a TCI 4400 to a Yank PT 4000 and swapped the rear gears from a 4.10 - 3.73. I also changed the Pacesetter headers and off road Y-pipe out with the Kooks 1 3/4" headers and catted y-pipe. (looking for something a little more streetable). Now something has gone way bad. Each dyno pull showed less and less HP & TQ. It is now down to 317 rwhp ( open headers ) and 320+- tq. What happened? It won't even break the tires loose now.

sidewayz28

iTrader: (24)

did you dyno on a different dyno?

'Trust'

iTrader: (24)

Well 436 RWTQ had to be from a converter spike, thats alot of TQ unless you are FI. Whats the complete mod list on the car. What dyno's were you on? Mustang, DynoJet? Same or different on each pull. Do you have any of the WinPEP files from the run?

BLAKE 01 WS6

iTrader: (1)

may be a dumb question, but did you put fresh gas in it?

Blown2000SS

loose convertor

evojuiced

I say Broken/Fouled Plugs.......

ArcticZ28

iTrader: (14)

Change the fuel filter as of lately? That along with new plugs, oil, and gas are a must before it even should get close to the dyno. I'd also check fuel pressure at idle and WOT to make sure it's not crapped out. Put up the graph so we can see if anything looks fishy.

Johnie_West

OK,
1) It was the same kind of dyno but not the same dyno. DynoJet 248
2) TQ numbers was a spike
3) I changed the plugs before dyno
4) Motor sounds like it is doing what it is supposed to be doing
5) No power to the wheels
6) Maybe weak springs due to the long sit without starting?
7) We installed a Magnaflow catted y-pipe and it gutted the drivers side cat immediately upon getting on the dyno?
8) Dyno numbers decreased on every run some were below 300 rwhp
9) Loose converter? I don't think so. I have had a 4400 in the same car and it would light the tires up effortlessly. This one won't even break them loose on street tires. - no power
10) Bad tune?
11) Bad converter?
12) Bad tranny?
13) Dyno graph was so faint my scanner won't pick up the lines. What should I be looking for on it?

blubird

iTrader: (8)

I'm going to guess number 6, but you should be able to tell that from the dyno graphs. If your car sat that long your fuel system could be part of the issue as well.

98Z28MASS

iTrader: (6)

I would agree with most of whats been said. Replace the fuel filter and make sure your getting enough fuel pressure and that your injectors are not clogged/fuel pump isnt going on you. Also make sure your not using the same gas that has been sitting in the car for a year. Other than that maybe your rear is going or yoru tranny is shot?

SHINER

iTrader: (18)

sounds like a spark/fuel issue.

98_Formula

iTrader: (15)

are you throwing any codes? did you change ur 02's when u swapped headers? maybe there is an exhaust leak b4 the 02's? g/l either way

Ericbigmac83

iTrader: (19)

Trace the lines and then rescan it

Johnie_West

I'm taking out the fuel problem issue. I have been driving the car lately and have run several tanks of gas through it. The problem occured immediately after the converter swap. I have been having small tranny issues before and maybe this big converter has just intensified the problem. I'm going with the tranny rebuild. It was coming sooner or later so it might as well be sooner. It was a stock tranny with 44,000 miles on it and a lot of sticky launches. I like to think of it as money well spent as to wasted. If that doesn't fix it, I'll go into the motor....fuel and valvetrain. Thanks for all the replies. They have helped me look in all directions.

bjamick

iTrader: (31)

Im going with the converter. Now was this unlocked dyno numbers? because if it was usually when you lock a converter you pick up like 40-50hp.