10 TVS GT500 lost power after kooks LT Headers

[5PointOHNO]

Unsure how this happened.

After installing kooks LTs, catted X-pipe, this GT500 is down on HP in a big way.

Mod list:
jLT 127mm
Frpp twin 65mm TB
TVS blower with 2.4 pulley
Afco HE
170 stat
Kooks LTs
kooks catted X pipe
Stock axlebacks
New tr6 plugs

After installing the LTs, x pipe and HE I saw some serious timing being pulled and it turned out to be a bad IC pump. That's now been corrected but the car made 688rwhp prior to the LTs and yet it feels and runs like a 120mph 580 rwhp car.

Just got run down by a 125 mph car.

I even reloaded the tune from the pre-LT days and it's unchanged.

Any thoughts on what could be causing this?

 

[res0n0xg]

Catted x pipe would be my first thought plus with long tubes you lose about 2lbs of boost. Aftermarket cats and 700 hp don't mix usually. I would worry about a clogged cat.

 

[1320 Junkie]

Something is def wrong...headers add a solid 20-30 rwhp

 

[99SSls1]

Find a dyno and get it there.

 

[Kenneth]

Something is def wrong...headers add a solid 20-30 rwhp

True.
I believe I picked up 35hp 30 torque when I added long tubes to my car.
Only other change was adjustment in tune for the long tubes.

 

[99cobraUgotbit]

Unsure how this happened.

After installing kooks LTs, catted X-pipe, this GT500 is down on HP in a big way.

Mod list:
jLT 127mm
Frpp twin 65mm TB
TVS blower with 2.4 pulley
Afco HE
170 stat
Kooks LTs
kooks catted X pipe
Stock axlebacks
New tr6 plugs

After installing the LTs, x pipe and HE I saw some serious timing being pulled and it turned out to be a bad IC pump. That's now been corrected but the car made 688rwhp prior to the LTs and yet it feels and runs like a 120mph 580 rwhp car.

Just got run down by a 125 mph car.

I even reloaded the tune from the pre-LT days and it's unchanged.

Any thoughts on what could be causing this?

Those numbers seem high without LTs.

 

[5PointOHNO]

Those numbers seem high without LTs.

Those were STD numbers... SAE was something like 670 IIRC....

Car ran so well before LT's and Catted X.... note, it still had the factory cats when it made that power, so perhaps they flow better than the aftermarket "high-flow" cats?

Tune checks out - no issues there.

 

[Speedboosted]

What did your car trap before the long tubes?

 

[nxhappy]

get rid of that catted X....you are not letting those long tubes breathe ...

 

[2001Cobrabuddy]

Check the intake for leaks, had a similar issue with the intake and fuel trims excessively compensating. Didn't matter how well it was seated. Switched to an intake that fit like a glove and the trims are dead on.

 

[5PointOHNO]

Ran the car without cats, no difference.
Ran the car with different intake, no difference.
Compression test came back perfect.
Boost check netted ~15.5 PSI at WOT (seems a tad low for a 2.4 pulley)
Smoke revealed that, aside from what we think is normal EGR leakage, there are no other leaks.

This car is a mystery.

 

[5PointOHNO]

Datalog

Here is a datalog of the car.... this was just after the IC pump was replaced:

http://www.filedropper.com/nealsdatalogaftericpump

Let me know if you can see anything strange please

 

[Blackmax]

I lost 40 h.p. when I put on longtubes and it turned out to be a lousy tune.

 

[biminiLX]

What was boost before?
No timing being pulled?
Belt slip?
Sounds like it needs a 10% lower now
Good luck.
-J

 

[nxhappy]

I lost 40 h.p. when I put on longtubes and it turned out to be a lousy tune.

holy jesus 40whp....really ?