Disappointing performance after installing 2-cat X-pipe!

[Chris-90LX]

Has anyone ever installed a 2-cat X-pipe and have it take a serious toll on your performance at the track?

After running the car for the first time after having it installed last year, my trap speeds went down a solid 4MPH and my times have slipped a solid ½ second.

This is a Bassani 2 ½” system. I did back off my timing by 2 degrees and remove the set of under drive pulleys I had last year, but isn’t this kind of ridiculous?

My best time last year was a 14.39 around 97MPH and I made consistent mid 14 second passes all season. The best I could get the car to do last week was a 15.15@93MPH.

I’ll admit that my 60ft times were bad, but in comparison with some of last years runs with the same 60ft times the car is still 4MPH slower and a half second behind. After comparing slips from last season, I can see the car is lacking power all the way down the track. That strong 2nd to 3rd gear pull just isn't there.

I plan to make another track attempt next month. I’ll check the ignition tuning, the pulleys will go back on and bump the timing up.

Any comments?

 

[90_Red_LX]

Hmmm, I might trade you a o/r VRS midpipe for that catted one.

 

[Chris-90LX]

If everything points to the exhaust system after checking the motor out, I might consider only removing the cats and keeping the X-pipe.

Maybe I could slip in the cats at inspection sticker time, but run some kind of test pipe in their place when performance counts.

This just isn't right!

The car is running slower than it did in stock trim!

 

[T_5.0_N'works]

Try a tune up, cap, rotor, plugs, wires.

 

[Chris-90LX]

I plan on giving the motor a good looking over!

Before the next track trip I'll:

1) Look over the whole ignition system. The last tune-up was 17k miles ago in 2000.

2) Check engine vacuum with a vacuum gage to maybe see if there is anything suddenly wrong with the engine internals or maybe too much back pressure.

3) Reinstall the pulleys and bump the timing back up to 14 degrees.

4) Clean out the fuel injectors.

5) Run the car in August to see if anything changes time or speed wise!

The question is, how much should cats be slowing the car down?

According to the horsepower calculators, I've lost about 18hp!

 

[Maryland Stang]

Before you get all excited try bumping the timing back up and put the underdrives back on. When I installed a full exhaust system, including a non-catted h-pipe, on my Stang last month I couldn't tell a whole lot of difference. When I installed my underdrives 2 weeks ago there was a huge difference.

Before when I finally got my Stang hooked up in first gear it would stay hooked up. Now when I get it hooked up in first it stays hooked until about 4k RPM and then it spins the tires hard. That tells me that it is making more horsepower with the underdrives.

 

[Chris-90LX]

Over the last few days, I've looked things over. Other than the spark plugs looking on the lean side, the ignition system looks good.

I attached a vacuum age and all looks well. There were no strange vacuum readings telling me tales about backpressure or internals going bad.

I disconnected the mass air meter and it turned out to be clean.


7/23/04 Obtained an Actron code scanner. After following the instructions, the results showed:

KOEO - #85- “Canister Purge (CANP) solenoid-circuit failure.
or,
Transaxle problem –3/4 shift solenoid circuit failure
or,
Electronic Control assembly (ECA) status-adaptive “lean” limit reached in fuel control program.”

KOER - #22- “Manifold Absolute Pressure (MAP) sensor or Barometric Pressure (BP) sensor signal voltage out of
specification (engine off) or not at normal vacuum levels (engine running)”.

KOER - #32- “EGR Valve Position (EVP) sensor or Pressure feedback EGR (PFE) sensor- signal voltage is below closed limits
or,
had gone beyond set limits.
or,
Problems with EGR valve controlling”.

So how do I decipher this stuff? It looks like the spark plugs were showing a lean a/f mixture after all.

Should I next investigate what that BP sensor and EGR valve area are doing for me?

Which of the spot above would most likely lead to causing a lean a/f mixture?

Tomorow I plan to attach a fuel pressure gauge to the fuel rails. I'll see what kind of fuel pressure I'm getting with different RPM ranges.

 

[blackstangt]

well, the weather, such as density altitude could have been different. a stock car runs best with 14 deg timing for racing. a tune up is definately a good idea. fix/replace egr. just try again, it may have just been a bad day for you... we all get them.

 

[Chris-90LX]

7/24/04 I checked my Actron scanner codes with the Actron manual and my “How to modify and tune Ford Fuel Injection” book.

KOEO- #85- “Canister Purge (CANP) solenoid-circuit failure . The solenoid is shot. It had no continuity at all between its pins. It should have showed 40-90 ohms. Ford wants $52 for a new one. I haven’t exhausted my search for another OEM type of supplier.


KOER- #32- “EGR Valve Position (EVP) sensor or Pressure feedback EGR (PFE) sensor- signal voltage is below closed limits or, had gone beyond set limits.

I checked to see if the EGR’s vacuum diaphragm was still working. It held vacuum fine. I then checked to see if the sensor was working with a multi tester. It was working like it should when the diaphragm moved. It appears the EGR was binding some.

I ran the two tests again and the only hanger is the broken charcoal canister solenoid from code #85.

The KOER test was clear of codes. I only saw the “system pass” code!

The next item up for bid will be to see how the fuel pressure is holding up.

I want be fully convinced that anything was “fixed” until I see what kind of fuel pressure this 14 year-old pump is still making.

Thanks for the guidance!!

 

[22Stang]

Chris-90

I have that COde 32 during my KOEO test cant figure it out, I did the tests like you did, any ideas what else I should do. I already replaced the EGR valve and the sensor. I am totally stumped.

 

[robertdale]

It's hard to compare the performance of a car at the track after an entire year. It's impossible to have the exact same conditions two days apart let alone a year. the only way to correctly compare the x pipe, is to put the stock pipe on and run, then switch straight to the x pipe and run the same day. But a tune might get you the desired results you are looking for.

 

[Daggar]

It's hard to compare the performance of a car at the track after an entire year. It's impossible to have the exact same conditions two days apart let alone a year. the only way to correctly compare the x pipe, is to put the stock pipe on and run, then switch straight to the x pipe and run the same day. But a tune might get you the desired results you are looking for.

Also.... I've seen a awful lot of articles about how free flowing exhaust components might give you better HP but.... they can also decrease your HP and torque at the bottom of the RPM range. You'll need to look at the whole cost/benefit thing before you decide what you're eventually gong to run. Your 60 foot times might be worse but perhaps you'll gain more than the offset up top.

 

[Chris-90LX]

Chris-90

I have that COde 32 during my KOEO test cant figure it out, I did the tests like you did, any ideas what else I should do. I already replaced the EGR valve and the sensor. I am totally stumped.

KOER- #32- “EGR Valve Position (EVP) sensor or Pressure feedback EGR (PFE) sensor- signal voltage is below closed limits or, had gone beyond set limits.
or,
Problems with EGR valve controlling”.

Did you disconnect the battery? It's common practice to not have power in the system for a period of time so that the computer will clear the hard codes. The generaly like 20 minutes.

The next lead I’d go after is to see if there is vacuum pulling the EGR diaphragm.

Do you get any codes with the KOEO test?


Keep us posted!