Need advice for slowing my car down consistently.

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toolmanmike said:
A simple throttle stop is all you need! http://www.summitracing.com/parts/mor-65042/overview/
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X2
A lot of ET racers build a motor that makes the car go too fast. They use a throttle stop to keep the car from going into the next et bracket that requires a beefier cage or expensive safety equipment. As long as you heat the tires the same, stage the same and shift the same your et's will be very close to the same. No need to build a different engine or replace the converter or have someone fab a restrictor plate. (Those guys turn left and you don't want to do that) LOL
 
Pneumatic throttle stop powered by a co2 bottle...set it up to pull back in 2nd or high.....what ever is needed....
 
Ok, something is not making sense here. When testing last night (almost no cars there due to a threat of rain)....got 3 passes in before getting rained out. First pass was with the car weighed down and the throttle cable moved 1/4 inch the car ran 11.17. Second pass, I move the throttle cable another 1/4 inch and it ran 11.09 (say what???). 3rd pass, I removed over an inch of travel out of my throttle cable, my gas peddle is almost laying on the floor of my car...I mean, the peddle barley moves.... I launch the car and it feels a little lethargic, then a second into the run it starts taking off like a banshee....and the car is STILL running 11.3 :banghead: (I'm trying to slow it down to 12.0). This doesn't make sense to me. I'm only getting MAYBE 1/4 throttle...MAYBE.... and the car is only slowing by about half a second (would have probably run 10.8 in these conditions at full throttle).....what the crap!

I'm going to have to change plans because I can't move the throttle cable any further forward...these is no place left to clamp it....I guess I'll be making that throttle stop after all, or just saying screw it and run Pro.:banghead:

I think famous bob had it right (a few posts back), I should stay in Pro and just win more...lol.
 
Ironic that one is upset that the car is faster when trying to slow it down. Good luck!!
 
I have found that it just as hard to slow a car down as it it to make it faster.

When to Firebird raceways in Idaho. Wanted to stay in sportsmen but the cut off was 14.0 At RMR my best was 14.14 but usually in the 14.20.

Firebird was lower altituted so i make up a spacer rod for my throttle so that i could only get half throttle, drop 5* timing and short shifted (800 rpm less)

What did i do......ran my first 13 sec run! (13.95)

As other have said, try and find a sponsor to help you thru, and run Pro.
 
Locomotion said:
It would only help a little bit, but there's always the option of adding weight - approx. 100lbs per .010. Of course you can only do so much and it needs to be done safely and legally. Best thing about it is that it would help quite a bit against spinning!

Less gear and/or taller tires? But that's getting expensive.
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I was thinking weight. Lots of weight...lol. Easier to be consistent with the package. Taking out timing or partially shutting the carb will change a lot and like Loco said consistency will suffer.
 
Leave in second gear,disconnect the carbs secondaries are 2 that I have found work very well. Depends on how much you need to kill.
 
Went back and read a bit. Do the above and then take out a little timing,add weight,you should be able to get there but it will take some experimenting. My street car would slow to 11.50's with a second gear leave and the carbs secondarys disconnected. Pretty funny as slow as it was off the line still passing the SB chevy 4.56 geared cars before the stripe despite the large gap in the early part of the track. LOL
 
DO you have a way to pull out timing with RPM? I effectively slowed a car from 11.13 down to 12.0s short shifting and having 10 degrees of timing pulled out past 4500 RPM. Dropped shifts from 6300 to 5600. I was using a lockup converter, so the early shift into 3rd with lockup really slowed it down. Look into a high speed timing retard.
 
I always like to leave easy and have the car come on at the big end. You can only imagine what the sandbaggers thought when they where out 3 cars on me at the 1/8th and they back off only to see me go by on the big end. Or they panic and mat it as they know I am coming and break out.

I would say just run the 10.90 class and enjoy it.. I am doing that in my 65...
 
I am in no way near a pro racer, I do enjoy our 1/8 mile track now and then.
Remove the skinny front tires and run as low air pressure as you can to stay safe
is one thing that will hold you back, heavy tire in the front with low air pressure.
OK, everyone can have a laugh know Add A/C to it and an alternator :glasses7:
 
I would not run low pressure in the fronts...lol. Ever feel what that's like at 100+mph when you let off and have to stop?
 
boosted said:
Can we say butt pucker....lol... and last turn off....
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I was successful in slowing my previous car down from the 9.90 to the 10.90 class. The car full out would run 9.76.
Anyway I had a 5000 stall too so I used a combination of removing throttle, lowering my shift points to 5300 from 5800 and setting my 2 step on the stall to 2200.
In 9.90 it was a .400 pro tree so coming off the 5000 converter as ok but when I switched to the 10.90 class the tree was .500 so lowering the 2 step to 2200 not only slowed the car reaction time it also slowed the et.

Good luck
 
boosted said:
Can we say butt pucker....lol... and last turn off....
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i had a low skinny front runner once... ONCE. 4 wheel manual drums and manual steering in an E body...lol - and the end of the track was Jersey barriers and the last turn off felt like it was never swept clean before use...lol.
 
Well, I build a throttle stop...I hope I get the setting close to perfect on the first try (yeah right!)....First race of the season is tomorrow....should be fun regardless. 8)
 
moper said:
I would not run low pressure in the fronts...lol. Ever feel what that's like at 100+mph when you let off and have to stop?
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I said remove the pie cutters and put a full size tire up front and do it safely :coffee2:

boosted said:
Can we say butt pucker....lol... and last turn off....
Click to expand...
I removed my 235 70 15 heavy radial tires on a 9.30 car and gained over 0.30 to a 8.70 pass, I puckered stopping with the pie cutters on it.

moper said:
i had a low skinny front runner once... ONCE. 4 wheel manual drums and manual steering in an E body...lol - and the end of the track was Jersey barriers and the last turn off felt like it was never swept clean before use...lol.
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I bet it did :coffee2: but if you had a full size
tire up front I would think you would have found control and made a better stop..



Just saying guy's, these front full size tires WILL slow your car down alot..

I hope your throttle stop worked out for you flyfish, I will keep my hillbilly racing ideas to myself and let the pro's jump in. How did your day go yesterday :coffee2:
 
Well….my throttle stop didn’t work at all….and there is no logical reason that I can think of to describe what the car did. I really don’t even want to post this because it makes no sense (and sounds like a fish story)….but, here goes.

1st practice run with my throttle stop on, gas pedal would barely move (which is what I wanted)…I launch the car, it feels like a slug for about a half second, then it starts running HARD down the track…Runs 10.95 @ 122.89 MPH… With the weather conditions and weight on the car, on an all out pass I should have run a 10.80 at the same MPH. My foot was nowhere near the floor when I went down the track. I got back to the pit, double checked to make sure the stop didn’t fall off or bend/break…nope, worked just fine, the secondary’s were not opening at all. Needless to say, I must have a pretty serious carburetor issue, or I somehow made my car capable of running 9’s just by changing the oil last week LOL. So after that, for the second time run I just pulled the stop off the car and ran the car to the 1/8 mile and coasted for the last half of the track. This usually gets me close to 12.0 at about 75mph, then it’s just fender racing for the last 100 feet. I got down to 9 cars before I took WAY too much stripe and broke out, but it was a fun day playing at the track.

I’ll be tearing the carb down this week to see if I can find anything before my next race (this coming weekend). Oh well, I will probably just scrap this sportsman stuff and go back to pro where the car belongs….I never knew slowing a car down would be so tough, lol.
 
If you have a vac secondary and the rod isn't set right, you could be getting full throttle on the secondary even though you have limited the primary..............
 
**Update**

Just in case anyone wants to know how to go slower....((crickets chirping)).....And now that no one is listening...:D...I've gotten closer to getting my car into the 12 consistently. This is where it sits now:

I added as much weight to the car as possible (safely). I removed the secondaries on the carb (now its a 2 barrel), backed the timing off 10 degrees (25° total currently), and I'm short shifting at 5500 RPM (I normally shift at 6500). This combo has slowed the car a little over a second.

This has gotten me close...Monday I raced it like this and lifted at the 1000 foot marker to run 12.05. Looking at the incrementals, I think this would have been an 11.87 pass if I ran it out...so, I'll probably pull a little more timing and call it good.
 
Might try some exhaust restriction/tuning ie mufflers
and less carb.
Cam timing will kill it.
 
Years ago a friend of mine wanted to do the same thing, but at the track to run two different classes. We came up with a quick solution. Duct taped a half inch drive one inch socket under the pedal. He was dead on consistant all day. Not exactly the perfect way of doing things, but in a pinch it worked good. Like a throttle stop. He staged the car the same and throttled it the same but with the socket there it stayed consistant. That day he got runner up in the slower class and went 4 rounds in the fast class. Simple, yes and it worked. Costs nothing.
 
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