Weird experience while topping out car racing and wondered if anyone else has exp this...
08-15-2001, 09:46 AM
#1
AudiWorld Senior Member
Thread Starter
Join Date: Jun 2000
Posts: 607
Likes: 0
Received 0 Likes
on
0 Posts
Weird experience while topping out car racing and wondered if anyone else has exp this...
A bit long....
Had my car back about 3 weeks now since I have had the new engine head/valves in. Timing belt went a few months ago and....you know what happens. Anyways I was racing a Honda Civic that had a turbo kit, front mount intercooler, and the whole nine yards. The thing was pretty quick actually. We were doing between 140-150. I couldn't glance at the speedo long enough to tell exactly. My brother was with me and said that the speedo was closer to 150. Wish I knew exactly.
This is what happend: The engine completely backed off for a second...Almost like the throttle had closed or something. The only way that I can really describe the feeling is whenever your foot slips of the gas pedal accidently...that's how this felt. Scared the **** of me. I though I broke my damn timing belt again or something else for that matter. I have taken it up to 140 before, but never much more than that, so I don't know if my car has a speed limiter. Is that possible? I pulled over immediately after it happend to inspect and didn't see anything wrong with my throttle body boot and it was still attached. The car runs fine and runs as if this never happend, or any damage was ever done. Has this happend to anyone else? I tell you what, my heart skipped a beat or two. Worse thing out of it was that I had to stop and the guy kept going probably thinking he won the damn race.
David
Had my car back about 3 weeks now since I have had the new engine head/valves in. Timing belt went a few months ago and....you know what happens. Anyways I was racing a Honda Civic that had a turbo kit, front mount intercooler, and the whole nine yards. The thing was pretty quick actually. We were doing between 140-150. I couldn't glance at the speedo long enough to tell exactly. My brother was with me and said that the speedo was closer to 150. Wish I knew exactly.
This is what happend: The engine completely backed off for a second...Almost like the throttle had closed or something. The only way that I can really describe the feeling is whenever your foot slips of the gas pedal accidently...that's how this felt. Scared the **** of me. I though I broke my damn timing belt again or something else for that matter. I have taken it up to 140 before, but never much more than that, so I don't know if my car has a speed limiter. Is that possible? I pulled over immediately after it happend to inspect and didn't see anything wrong with my throttle body boot and it was still attached. The car runs fine and runs as if this never happend, or any damage was ever done. Has this happend to anyone else? I tell you what, my heart skipped a beat or two. Worse thing out of it was that I had to stop and the guy kept going probably thinking he won the damn race.
David
08-15-2001, 09:59 AM
#2
AudiWorld Super User
Join Date: Nov 2000
Posts: 6,270
Likes: 0
Received 0 Likes
on
0 Posts
Maybe you hit the rev limiter....
I'm really not sure what the limit is with a GIAC, but 6600 RPM with stock 16" tires is about 150mph If your 18s have less diameter, then your RPMs will be higher for the same speed.
It's possible that you were running on the edge of detonation, and the ECU retarded the timing enough so that your HP dropped below the amount necessary to sustain your speed.
Besides, I wouldn't trust your speedometer at those speeds. It is not calibrated. If you know what your RPMs were, and actual tire diameter, it's easy to find your actual speed.
It's possible that you were running on the edge of detonation, and the ECU retarded the timing enough so that your HP dropped below the amount necessary to sustain your speed.
Besides, I wouldn't trust your speedometer at those speeds. It is not calibrated. If you know what your RPMs were, and actual tire diameter, it's easy to find your actual speed.
08-15-2001, 10:08 AM
#3
AudiWorld Super User
Join Date: Mar 2000
Posts: 9,705
Likes: 0
Received 0 Likes
on
0 Posts
You either hit a rev limiter or a hidden speed limiter.
I remember a while back Renntech was having trouble getting top speed in that 200mph Benz....they kept find these hidden limiters. Even though you have a chip, there still might be something in the ECU to limit your top speed.
08-15-2001, 10:13 AM
#4
AudiWorld Senior Member
Thread Starter
Join Date: Jun 2000
Posts: 607
Likes: 0
Received 0 Likes
on
0 Posts
Interesting....
about the timing retard. I don't have a VAG so I can't do the detailed searches and such to my motor/temps etc. My tires and rims should be pretty close to what the stock 16" are in diameter. I am running 18's with 40 series tires and compared them to my stock ones before I sold them. The diameter was pretty close. I have never experienced detonation like that though if it was. That is definitely a possible reason. Is that how the car acts under timing retard like that? It was surely a noticeable jerk and throttle pause. My engine head was also cut/shaved a few milimeters before it was installed and I hope that it didn't have anything to do with it.
Thanks for your input Johnny!
Glad your car is running again.
David
Thanks for your input Johnny!
Glad your car is running again.
David
08-15-2001, 10:20 AM
#5
AudiWorld Member
Join Date: Mar 2000
Posts: 342
Likes: 0
Received 0 Likes
on
0 Posts
Hmmm, sounds like fuel shutoff:
I did the same thing at ~125 in my Dad's Maxima. Car was pulling hard, hit ~125 and car had no power. Speed fell back to ~115, then power was back. I did it again with same results. Since it was only the GXE, there is a rev limiter due to no speed rated tires (Maxima SE is good for 140+).
Curious about the Honda, maybe a fake turbo or the stock (D16) motor with a turbo. A Hybrid (Civic with Integra or Prelude powerplant) is fierce with a turbo...
Take care,
FB
Curious about the Honda, maybe a fake turbo or the stock (D16) motor with a turbo. A Hybrid (Civic with Integra or Prelude powerplant) is fierce with a turbo...
Take care,
FB
08-15-2001, 10:27 AM
#6
AudiWorld Senior Member
Thread Starter
Join Date: Jun 2000
Posts: 607
Likes: 0
Received 0 Likes
on
0 Posts
Cool. I hope that's all it was.....
I do remember when Renntech was doing those speed tests. Maybe what I'll do is top it out one day again and have someone watch the speedo if and when it happens again. Wish I knew exactly how fast I was going darn it! I guess the Audi designers didn't want us going too fast :P
David
David
08-15-2001, 10:35 AM
#7
AudiWorld Senior Member
Thread Starter
Join Date: Jun 2000
Posts: 607
Likes: 0
Received 0 Likes
on
0 Posts
I'm sure that the Honda had the stock block....
with a bolt on turbo kit or something. The intercooler looked definitely real. Unless they make a really great fake one to insert in the grill area. I eyeballed it before we hit the freeway. You are right about them being fierce with hybrids and motor swaps. They are pretty fast when tricked out like that. They are just so damn light that it really gives them additional pull.
When you said that the fuel shutoff, you mean due to the speed-limiter correct?
Dave
When you said that the fuel shutoff, you mean due to the speed-limiter correct?
Dave
Trending Topics
08-16-2001, 12:46 AM
#9
Senior Member
Join Date: Aug 2000
Posts: 6,193
Likes: 0
Received 0 Likes
on
0 Posts
shaved head, that would increase compression making detonation more likely
not shure how much though
but if you have a 1.8t manual you would have been on the rev limiter, thats my guess as to what you're problem was
but if you have a 1.8t manual you would have been on the rev limiter, thats my guess as to what you're problem was
