CSX 3170 testing results

[Cobra #3170]

We got some good results in all areas except brake knock back but I have a couple of ideas to try. The new 5.5" crank pulley has completely cured the belt tossing problem. I have a 7.1" water pump pulley and a 3.2" alternator pulley and am using a Dayco 15425 belt. Turned it 8200 and hit the limiter and the belt stayed on. The new floating rotors have only .010 lateral float, I am trying .020 tomorrow by loosening the bolts for a quick trial. if that works I will spot face the rotor mounting surface down .010. We tried a new front splitter, and some Rival-S rears in 335x18. It took some tuning on ride height and shocks but we picked up 1 second on the 32 second test course that AAS rents out at Crows Landing.
The car is pulling 1.4 G's on street tires now so we are pretty happy. The splitter gave us enough front down force to make Bridgestone 275x18 RE-71's work very well. The brakes are much better with the new rotors in terms of decel and modulation too so if we fix knock back we should be good. The car is so good now that in the actual event I straight timed last years Goodguys overall Champion by .5 seconds on my first run and as most of you know I am a very old man. Scott got him by 2.6 seconds so we are going in the right direction. The car needed a ride height adjustment so it can be faster yet. All in all a successful weekend. We are going to check alignment and corner weight it before heading to Nebraska on the 2nd of September and add about .030 rear toe in. The splitter I made bolts to the two quick jack adapters in front and to the front sway bar mounts at the rear so it does not require any body modifications. We do have to raise the car to install it though because it has tire air deflectors.

[Cobra #3170]

This is a video of Scott's best run, the course is really tight to simulate the type of course that SCCA will put on at the National Championship next month.
You can see how well the car handles by how quickly it responds to steering inputs.

[ame]https://www.youtube.com/watch?v=bkrxSBxhoBk[/ame]

[rodneym]

That was one hell of a run!

[xlr8tr]

holy cr*p!! nice work. any pictures of the new splitter?

[fordracing65]

Do you keep anything in the glove box, ever use the ashtray???

[RICK LAKE]

Cobra 3170 The video is cool. Scott driving is smooth.
Questions (2) The surface looks like concrete in the video, is this the surface you will be racing on in Sept? Different tires or suspension change for different surface?
Does Scott get a pulsation in the brake pedal? Is this front or rear problem? I would think that .020" of any movement would cause a brake problem even with a varible bias valve.
Final note, OLD MAN, MY A$$!!! You keep kicking butt and taking names. You are .5 seconds faster than the Champion, I will arrange a pitty party for you That's it. I bet you can't run in that Opitma Challenge again, They would really be sorry. Maybe it's time to do the GT-40 and Kick some butt Nice job Rick

[Ron61]

The car is looking really good and the video really shows how well it is handling. That is impressive Gs on street tires. I will be looking forward to more videos as you run it and make more improvements.

Ron

[Racer_X]

Very impressive run! I enjoyed it from this view, but would rather be in the driver seat. This is the next best thing

[Cobra #3170]

Originally Posted by fordracing65

Do you keep anything in the glove box, ever use the ashtray???

Actually the fuel injection computer and power strip for MSD are in the glove box to keep it cool. I put time slips in the ash tray because it is handy to store them. So yes all space is used.

XLR8T, Splitter pictures, I have a hard time posting pictures because of the size limit maybe I could use a hosting site. I will try to take some today.

Rick, the floating rotors are supposed to ride between the pads and not push the pistons back. I think the spindle is flexing enough to push them back so by adding clearance they will have more room to move without pushing the pistons.
Brakes are normal till you hit a turn hard then they go to floor. I don't have the problem because I left foot brake and ride the pedal the whole time. Scott left foots the normal way and does not touch the brake until he needs it and then it goes to the floor because the pads are knocked back by the last corner. Since he is the best driver I want the car to work for him so he does not have to alter his style.
Surface is identical to Nebraska, both old airbases so a great warm up for nationals

[maurice19]

Awesome ride.

I especially liked how it seemed that the car followed the lead of his helmet, nod left nod right, etc.

Maurice

[Legless]

Hi Maurice,
Any decent driver will turn their head and look through a turn to where they want to go, at least that's what they've tried to drum into my head in any advanced driving instruction. Great run!

[slider701]

Bruce,

Do you ever take your car to the big tracks or is everything you do is on auto cross type tracks? I think we would all love to see 3170 turning laps at a place like Laguna or Road America.

[Cobra #3170]

Originally Posted by slider701

Bruce,

Do you ever take your car to the big tracks or is everything you do is on auto cross type tracks? I think we would all love to see 3170 turning laps at a place like Laguna or Road America.

I ran the Reunion at Laguna in 2012 and ran at the SAAC convention at Sears Point in 2010. I am too old to do that any more and the car is scary fast at full on road courses. At Laguna it was breaking loose from 11 to the top of the hill on vintage tires. At sears it got to 160 MPH between the carousel and turn 7,
it has the original roll bar and a stainless non-fuel cell tank. So a crash could mean death and after this long I don't want to go out just yet. I have raced other cars at Road America and cannot imagine the speeds it could get to going down the hill to 5 especially with no aero to plant it like Morris has. It is just an autox car now and we are having great fun developing it for that purpose.

[Cobra #3170]

I ran the brake test today and it looks like .020" of lateral movement of the brake rotors on the mounting bobbins solves the knockback problem. I drove it around the neighborhood and it worked perfectly. We will need to test it in an autox but it seems good so far.