Defeated at GoodGuys

[Tommy]

I would agree that too much power is better than too little, but maybe there's another option. Is there a practical and easy way to dial back the power for a given situation so the driver can focus more on handling than throttle control? For example, would a solenoid operated throttle stop that limits throttle opening in first gear be practical?

[dallas_]

Originally Posted by Cobra #3170

The car would be much faster with a 300 HP small block but what fun is that?

Yep, I like the way you think!

[Cobra #3170]

Originally Posted by Tommy

I would agree that too much power is better than too little, but maybe there's another option. Is there a practical and easy way to dial back the power for a given situation so the driver can focus more on handling than throttle control? For example, would a solenoid operated throttle stop that limits throttle opening in first gear be practical?

Tommy,
Unfortunately this engine likes a lot of throttle at low rpm then you back out of it before it wakes up completely. That is how we drive it when not showing off.
Putting the quiet mufflers on knocks about 100 off and makes the SCCA happy. We can also pull some timing and tame it a bit. A throttle stop would hurt performance so we just need to drive it more carefully. We put the big mufflers on at GoodGuys so people could hear because Danny Popp and the chevy guys were all pretty loud (could not have them out noise us). It really can be pretty drivable with small mufflers (2") and some timing out but that still takes throttle discipline something I don't have but Scott does. It is a lot like a sprinter on dirt except they have more traction.
I just found that one of the last minute changes I made screwed up our front roll centers so putting it back to initial design should improve performance.

[Snake2998]

On tracks where too much power is a problem why not fit a restriction plate upstream of the carb - won't affect low rev power but will limit open throttle power - nice quick at track mod and you can carry several sizes to try.

A simple solution is an Aluminium band fitted round the air filter with a suitable number of holes drilled in it - you can have several strips with differing hole patterns and sizes - would take seconds to change between runs till you get the right size for the conditions. This assumes your filter assembly can withstand some negative pressure but its much easier than changing mufflers and easy enough to build a filter setub to withstand negative pressure.

[twin turbo]

It's hard to believe the crowd wouldn't realize how little throttle was being used or could be used on that tight little course. As a spectator, I would want to see the participants be able to blip the throttle at least once. Looks like a perfect track for a Mini or go-cart. Are most of the courses set up that tight?

[Cobra #3170]

Originally Posted by Snake2998

On tracks where too much power is a problem why not fit a restriction plate upstream of the carb - won't affect low rev power but will limit open throttle power - nice quick at track mod and you can carry several sizes to try.

A simple solution is an Aluminium band fitted round the air filter with a suitable number of holes drilled in it - you can have several strips with differing hole patterns and sizes - would take seconds to change between runs till you get the right size for the conditions. This assumes your filter assembly can withstand some negative pressure but its much easier than changing mufflers and easy enough to build a filter setub to withstand negative pressure.

Sounds like am idea worth trying it has a 1650 cfm Wilson throttle body so I could fit the restrictor between the throttle body and spacer. I will give it a try, I have one from years ago when the SCCA made 427's run one under the carb.

[Cobra #3170]

Originally Posted by twin turbo

It's hard to believe the crowd wouldn't realize how little throttle was being used or could be used on that tight little course. As a spectator, I would want to see the participants be able to blip the throttle at least once. Looks like a perfect track for a Mini or go-cart. Are most of the courses set up that tight?

This course was way tighter than what we saw last year. We heard that some of our competitors encouraged the designer to tighten it up to make things"fair".
It is all good though, we will learn to make it work on the tight stuff as well as it does on the big stuff. I am all ready making changes that should help that I will detail here after we test next spring. The spectators there were really great, said so many nice things about the car that I lost count. I met several former owners and a lot of replica owners too. They were really on our side during the half shaft fix, so yes they would love to see some full throttle action.

[RICK LAKE]

Cobra3170 First off, Bruce the car is just an animal. Gear change IMO will not help. Go lower and load the drivetrain, Makes the motor work harder and not be in the power band of torque. When the motor gets into the torque range, the tires are smoked. Higher gear range the problem will be worse. Hit the throttle and smoke the tires quicker.
Have we looked into changing the ratio of the throttle linkage to slow it down? Some of the input will be the driver changing his style of throttle control. I am not in favor of traction control but Fred K from New Hamp has a setup that takes out timing when the ecu see slipping different between driveshaft outout and reartire speed change. He uses a FAST system. He might have a couple of ideas on this.
killing air flow with spacers or covers that limit air intake will cause reworking the fuel tables and timing. I don't think the motor will be happy at all. It's power design was for middle to large tracks. Top end on this car about 180mph. Having it run in a bull ring, just doesn't work. The other problem is THEY DON'T want you at these events. The car is stock body and frame with work from the 60's. You are kicking a$$ at each event unless the car break or driver error. They will change the track design to slow down the speed. This is not just you. I am guessing they are looking at safety also and want to keep the speed down incase of a car loosing control and hitting something not on the course.
Bottom line is too much motor. Detune it about 150hp. Your times will not change that much and maybe going to a 3.54 ratio will improve the accell and decell without blowing the tires or lockup. Using a higher rpm range might improve your time and handling also. Your driver is smooth and carefull from watching the videos. This makes the car fast.
Each event you run has a different surface. If you have the right tires to match great hookup and traction, great. IF not even your driver can over come a traction issue. It's like nascar, you will change shocks, springs, roll rate, stablizer bars and load, tires, and alignment. I am sure you have done it but are the tire temps about the same after a run or not enough heat buildup for good readings? I know you will not do this but good old down force of wings, spoilers and canards.
You have a great car that on any normal track can cover 98% of the field. Auto cross is a silly class of racing. Fun, low speed, Maybe 1 gear change, and power sliding a car. Running with the best and trying to beat them is what drives you. I guess keep beating on the drum and have them worry. You will change the suspension and come back with a better handling car, different tires, maybe a little less HP and scary the hell out of them again. Now that's fun. Private garage against the world, my favorite fight. Rick L.

[Three Peaks]

I love watching the videos and hearing all the modification your are willing to try to get maximum performance out of the cobra. My first thought is that you're having way too much fun with that car- most people would need 2 or 3 cars to have that much fun.....

Bob

[RET_COP]

Nice video and , good control. WoW 290s duration at .050 what the hell cam and upper end do you have in the car? How many CI? Like Rick said too much motor for that type of course. or the wrong cam for the combination which I'm sure is not the case. Please give me some engine specs.
I'm running a 359w 10.75:1 cr with Keith Craft ported Brodix 17* heads, a vic Jr. intake and a Jones custom cam with duration in the 230s topped off with a Pro-system 780cfm MS and its is a bear, very flat tourque curve and pulls good from 2000. I ran a tight course like the one you did and the car performed well, I just didn't. hope to get better. Good to hear of a bad COBRA keep us informed of other races.

[fordracing65]

The little wheelbase does not help either...except around a turn, I love it when you car needs to do a full circle around cones and it takes 2 seconds, everyone else almost need to do a 3 point turn at about 4seconds...

[REAL 1]

Winning will be that much sweeter next time.

You are obviously a good loser too which is the test of a man's character.