Found out why my car wouldn't run at the Shootout

David Neibert

SCCoA Admin
Took it to the muffler shop today and had the cats cut off...passenger side looked perfect, but the drivers side was a mess. On the inlet side of the cat the first stage of the honeycomb stuff was gone and about 60 % of the holes in the second stage were clogged with peices of the first stage. Could hardly see any light thru it.

They won't have the new cats installed until tomorrow morning. Wish I would have checked them before the Shootout, but I'm glad to finally find a reason for the lost power. As bad as that thing was clogged, I can't believe it actually pulled 300 rwhp at the shootout.

David

PS: Kurt Kreisz predicted that it may be a clogged cat.....once more I should have listened.
 
Wow David,
You are a pretty noble guy. I can't promise that my cats would even still be on the car since I have a special shop I take my car to for inspection. :p

Anyways, I am glad to hear that you got this straightened out. I hope XR7 Dave hosts another shootout after our Turbo deals get finished up. :eek:

I was really depressed that I had to miss this one, but that's how it is when you have more bills than cash. :(
 
dirtybird91 said:
Wow David,
You are a pretty noble guy. I can't promise that my cats would even still be on the car since I have a special shop I take my car to for inspection. :p

Anyways, I am glad to hear that you got this straightened out. I hope XR7 Dave hosts another shootout after our Turbo deals get finished up. :eek:

I was really depressed that I had to miss this one, but that's how it is when you have more bills than cash. :(


Frank,

I'm not that noble. My first call this morning was to a buddy who usually does the exhaust work to take him up on his offer to make the cats removable so I could run without them except when it's emissions testing time. Unfortunatly he no longer works there and none of the other places I called would do it.

I could have sawed them off and gutted them but then I would need to figure out a way to weld them back on. That's just too much of a hassel, so I decided to get new cats instead.

Wish you could have attended the shootout....even with my crappy running car we still had a great time.

David
 
I hear ya man!

It literally depressed me to miss a chance of meeting some of you guys in person. I think that would have been as interesting as the cars. I have made some really good cyberspace friends and I will be coming to the next shootout if I have to walk. :cool:

Frank
 
Hey Dave think about this. .. I had a exhaust shop that wouldn't eliminate my cats when it was time for me to pull out of the shop. So I asked him to set it up as follows:

Before each cat & after the resonator he setup flanges so I could remove it by taking out the 2 bolts at each location. Then he made an exact fit replacement of just down tubes into a resonator. Placing flanges at the exact locations, so when it's race season, you can just get under there & take out the 'cat & res' setup & replace with the 'res & race' (no cats) setup. The flanges are basically the same thing as where the down tubes meet the headers. Same idea.
 
Anthony,

That's pretty much what my buddy was going to do, but I'm not having much luck convincing the exhaust shops to do that. It should be fine for the time being. If the power gets back up to the 350-360 rwhp range I had last year, that will be plenty fast for this car.

The turbo car is the one I'm going all out on and there won't be cats or a resonator on it, just a pair of open chamber mufflers.

David
 
Car

Dave,

That great news that you may have found the car woes, I hope that is the cure. Kind of a bummer you did that other work and it could of been this the whole time!

Hope this is the problem solver, I want to see that thing in the 11's this year w/ only below a 100hp shot of nitrous!

Have a good one and keep us posted,
Brandon
 
Brandon,

If all goes to plan, Kurt K. and I will be going over to Gateway tomorrow night (slick tire test and tune). Temps should be in the mid 60s, so it will be pretty good weather for racing. I'm about 99% certian that the clogged cat was the main cause of my problems. Just wish I would have determined it a week sooner.

David

PS: I'm going back to the 100 hp shot I had in the car when it ran 11.7 last year.
 
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David
Glad you found the problem. How do you check for a clogged cat and do you know the cause of the clogging? Would the oil leakage have been a contributor? We also had valve seal failure and I'm sure oil in the cats.
 
Dick Hughes said:
David
Glad you found the problem. How do you check for a clogged cat and do you know the cause of the clogging? Would the oil leakage have been a contributor? We also had valve seal failure and I'm sure oil in the cats.

Hi Dick,

There isn't a good way to check for a clogged cat if you have a 2 into 1 into 2 exhaust system like I do. The usual signs of a clogged cat are loss of power, muffled sounding exhaust, unusually high boost and higher than normal operating temps.

I only had the fluttery muffled exhaust sound and loss of power. I was certian that it was one cylinder causing the problem, but that wasn't the case. The boost gauge usually pegs as quick as I hit the gas and this Griffin keeps the car running cool no matter what, so I didn't think it was a clogged cat.

I'm told that several things can lead to the failure of the cats. The main ones are antifreeze, excessive fuel, excessive oil and most of all leaded gas. I think mine was caused by a nitrous backfire when the fuel pressure regulator vacuum boost line came off while using nitrous at the track.

BTW, I picked up my car this evening from the muffler shop and the goofy exhaust sound is gone and even though it's running very rich, the missing power seems to be back. I got the car rolling to about 35 mph in 1st then nailed the throttle and the tires went up in smoke, just like old times :D .

Not sure how well it's going to do at the track because I haven't raced at full power with the current cam yet, but I'll find out tomorrow night. I'm guessing high to mid 11s on the bottle. If all goes well, I'll be getting kicked out again for not having a roll bar.

David
 
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Good Luck David

"Hope all goes well"
100 shot of Nitrous and if all works together drop your ET down ferther. them tech guys are a pain arnt they? we made two 11 second passes they where on our butt "dont come back without roll bar" hope you get some good runs in with cool weather :)
 
I told you to check for them, since that was my problem. I'm glad you figured out why it was running bad. :D

Did you break anything at the shootout? :rolleyes:


David
 
NCredSC said:
I told you to check for them, since that was my problem. I'm glad you figured out why it was running bad. :D

Did you break anything at the shootout? :rolleyes:


David

David,

No nothing broke...made 11 dyno pulls Thursday, about 6 runs at the track Friday, 2 more dyno pulls Saturday and a big a$$ rev limiter bouncing burnout at the hotel Saturday night just before putting it back on the trailer.

Jim,

I've already been kicked out of this track (Gateway) for running too quick, but that was on street tire night and I stuck out like a sore thumb because it was the fastest car there.

Tonight is slick tire test and tune and it will be one of the slowest cars. I hate racing against a 9 second car that is so loud I can't tell if my engine is even running. It's also a little unnerving when they come off that two stage rev limiter/trans brake and yank the wheels off the ground. Good news is, they aren't really concerned about a street car and probably wouldn't even notice if I ran 11s without a rollbar.

David
 
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David Neibert said:
I've already been kicked out of this track (Gateway) for running too quick, but that was on street tire night and I stuck out like a sore thumb because it was the fastest car there.

Tonight is slick tire test and tune and it will be one of the slowest cars. I hate racing against a 9 second car that is so loud I can't tell if my engine is even running. It's also a little unnerving when they come off that two stage rev limiter/trans brake and yank the wheels off the ground. Good news is, they aren't really concerned about a street car and probably wouldn't even notice if I ran 11s without a rollbar.

David
You know they will notice. And I'm sitll convinced that "slim" remembers you :)
 
Kurt K said:
You know they will notice. And I'm sitll convinced that "slim" remembers you :)

If you're referring to the tech guy over at Gateway that I think you are, I'd just like to throw in my personal disgust for that guy.

Good luck at the track tonight David, and let us know how it runs.

-Rod
 
David Neibert said:
I hate racing against a 9 second car that is so loud I can't tell if my engine is even running.
Put in some solenoid controlled exhaust cutouts after the cats, and that won't be a problem any more, just open it up at the track! The only problem then is going to be with your hearing. The first time I ran my car with the cutouts open, I had a helmet on but no ear plugs. After the run, my ears felt numb and were actually buzzing, it was worse than ringing! Took a couple hours for that to stop...
 
Heres my deal

Found out why my #s were down. sucks to find out now.
Thanks to stupid me for having to much timing. Thats ok though,
Dave next year you and I will have our own race team to fix us
up.

Chris
 

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Chris theres nothing wrong with those plugs :D . Just think how much faster your car will be with good plugs and wheels that dont rub. Do you plan on going to the track again?
 
David, make sure you check your O2s to see if they are working properly. I had a bad one from when the HGs blew and I guess the computer didn't know it was bad and was dumping too much fuel on the other side of the motor. Clogged tha cat!!!

I don't have that problem anymore. :D


David
 
racecougar said:
If you're referring to the tech guy over at Gateway that I think you are, I'd just like to throw in my personal disgust for that guy.
So you know him too :)

NCredSC said:
David, make sure you check your O2s to see if they are working properly. I had a bad one from when the HGs blew and I guess the computer didn't know it was bad and was dumping too much fuel on the other side of the motor. Clogged tha cat!!!
We replaced the O2 sensor early on in the trouble-shooting.

Anyway, besides the fact that David didn't get thrown out last night, we still had a great time. I even managed to back up my best Norwalk time and ran a 12.62 s @ 107.52 mph ... a new personal best.
 
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