CSX3170 Update

[Cobra #3170]

We did a test of 3170 last Sunday after months of work on it. It has fresh paint and the original bumpers back on and looks very much like it did when brand new. I did not reinstall the sun visors or wind wings though and the interior has racing seats etc. I have replaced the #16 oil supply hose and fittings, had new seals and O rings put in the Daily dry sump and replaced the
RH valve cover gasket and seem to have solved the oil leak problems. The electrical issues with the FAST system were solved by replacing the engine builders harness with a stock FAST harness. The tune is still way off because the builder just went for peak power and forgot about throttle response and proper air fuel ratios at partial throttle. We fixed about 70% of the problem but still have some flat spot issues due to lean A/F ratios. The smaller engine also needed lots more rear brake bias than the 498 because of lower internal drag. I have a short video of Scott trying second gear with traction control on and it actually worked fairly well. First gear blows the tires off because it still has so much torque even with 20 degrees of timing retard. The rear gear ratio is 4.88 with a 1.73 second gear. Second is good for 88 mph at 9300. It pull really well in second even at low speeds as you can see in the video. We are going to try some more tuning changes with help from FAST and run it next weekend. My fingers and toes are all crossed.
I hope this Google video works, never posted one before. Second gear pull with traction Control

https://youtu.be/Wh2Z1K88sEE

[twobjshelbys]

The video link didn't work.

But...

Are you sure the fuel injection is the right path? Do the adaptable/self-learning system allow you to go in manually, and do they have enough resolution to handle the abrupt changes that happen with auto-x driving? I went through a similar exercise with my DFI system (Accel) where they didn't do the altitude compensation, and in manual mode there were so many tunable parameters with such high degrees of interaction that it was a real nightmare. Given enough time and patience it could certainly be worked out for a custom application but in the end will there be a gain over a set of well tuned carbs?

[Cobra #3170]

Originally Posted by twobjshelbys

The video link didn't work.

But...

Are you sure the fuel injection is the right path? Do the adaptable/self-learning system allow you to go in manually, and do they have enough resolution to handle the abrupt changes that happen with auto-x driving? I went through a similar exercise with my DFI system (Accel) where they didn't do the altitude compensation, and in manual mode there were so many tunable parameters with such high degrees of interaction that it was a real nightmare. Given enough time and patience it could certainly be worked out for a custom application but in the end will there be a gain over a set of well tuned carbs?

Hi Tony,
The system runs in alpha N just like the 498 did, way too radical to do any self
learning, the old one worked perfectly in autox. The only reason I changed was to get traction control. I am pretty sure it can be fixed, with tuning we made major improvements just smoothing the base fuel tables and changing the TPS enrichment curve. Carbs cannot handle the g loads and stumble because of float slosh. We are getting 1.5 G cornering and 1.2 braking and accelerating on 200 TW tires now.

I am trying to find out how to embed a video from Google drive to CC but so far no luck, maybe somebody on CC will know how and tell me. You Tube is so easy!

[twobjshelbys]

Cant the video upload to youtube? Thta's what I've always used. Photobucket used to work but now they charge $500/year to embed off-site links so all of my pictures are now orphans

[twobjshelbys]

Originally Posted by Cobra #3170

Hi Tony,
The system runs in alpha N just like the 498 did, way too radical to do any self
learning, the old one worked perfectly in autox. The only reason I changed was to get traction control. I am pretty sure it can be fixed, with tuning we made major improvements just smoothing the base fuel tables and changing the TPS enrichment curve. Carbs cannot handle the g loads and stumble because of float slosh. We are getting 1.5 G cornering and 1.2 braking and accelerating on 200 TW tires now.

I think I understand. The "analog response" of the carb and floats can't deal with the impulse inputs on the x-cross run. Hopefully a digital oversampled system will be able to do it. To do that the system needs to be able to sample an actual run and somehow factor all of its variables into the DFI adjustment tables. The problem will be in the accel/decel transitions. I had the same thing happen to me - the tables didn't really understand what happened when you were (at the same place in the table) accelerating going up hill and decelerating going downhill during shifts. After we talked about what was happening the light in the room got real bright and he "got it" and was able to smooth the table across those spots but had to compromise it. It was better, still better than carbs, but compromised the overall performance to do it.

It certainly was an interesting experience but the PhDs in HDD servo controllers were able to explain it

[Cobra #3170]

I converted the video to you tube

[hinoonaz]

Will you be at the Good Guys in Scottsdale in two weeks? I hope so. Always enjoy you kicking the boys from New Mexico.

[Cobra #3170]

Originally Posted by hinoonaz

Will you be at the Good Guys in Scottsdale in two weeks? I hope so. Always enjoy you kicking the boys from New Mexico.

We are running the car at GoodGuys in Pleasanton this weekend and will be going to Scottsdale if it is still good to go after Pleasanton. We were told last night that the Cobra will not be allowed at 2018 GoodGuys events because they are initiating a 3200 pound minimum weight rule. We could never add 850 pounds safely so I guess we are out. Really too bad, because that leaves Ford out of the fight with Corvette. I am really disappointed that GoodGuys caved to the complaints from Corvette owners about the Cobra's light weight. My new engine, rear end ratio and rear suspension design changes were all for GoodGuys competition. I know the crowds love to see the car run. I hope they tell GoodGuys officials how much they miss the little Ford. I guess we will take it back to SCCA CAM-S. People do not realize how much effort goes into making a car fast, it isn't the light weight it is hours of testing and changing set ups to make it fast. Having the best autox driver in the country wheeling it is also a big factor.
Stop by and say hi if you are at Scottsdale GoodGuys.

[twobjshelbys]

The 2018 rules suck! It looks like they singled you out. It's like the balance of performance in FIA GT class against the Ford GT - weight and HP reductions to give old technology a chance instead of encouraging them to upgrade their technology.

[Morris]

Originally Posted by Cobra #3170

People do not realize how much effort goes into making a car fast, it isn't the light weight it is hours of testing and changing set ups to make it fast

It is a Labor of Love and many don't understand the commitment we make to ourselves to compete and complete a project.

Keep up the good work as it will come back to you in Spades

[1795]

Originally Posted by Morris

It is a Labor of Love and many don't understand the commitment we make to ourselves to compete and complete a project.

Keep up the good work as it will come back to you in Spades

So true 3170 and Morris. It is a constant state of flux when you compete. I do not think that you ever have a "completed" car. There is always something more that you can do to the car, and your driving skill. It does not end until you stop competing.

Jim

[hinoonaz]

I just sent a respectful memo to the controller of the Goodguys. I just let her know of all the Cobra owners understand that we are not welcome at there shows. I also stated the Corvettes will finally win! Could not help myself. Hope to see you in a couple weeks.
Gary

[Phx Mike]

This is really unfortunate. I hope they reconsider the rules change. 3200 lbs is ridiculous...might as well run a NASCAR car there :-).

Just like the old days - need to change the rules or cancel races to keep the Cobras from winning....

[hinoonaz]

My message to the Controller at the Good Guys got forwarded to Ed. Ed is in charge of the autocross since inception 12 years ago. I will not be able to quote verbatim but here it goes. There was talk about weight class divisions. Two seat car divisions. There is not going to be a restriction on weight ever. Basically run what you brung for now. The vettes and Cobras will battle as always in a two seater class if ever initiated. Now that I have mixed up the works, see you at the races One added note: the autocroass was started on the basis of a street car driven to show and runs. I personally don't care either way. I know I cannot compete with a lot of the cars. I don't even have the correct tires let alone a suspension set-up. Enjoy and love 3170 kicking some arse's Gary

[Cobra #3170]

Originally Posted by hinoonaz

My message to the Controller at the Good Guys got forwarded to Ed. Ed is in charge of the autocross since inception 12 years ago. I will not be able to quote verbatim but here it goes. There was talk about weight class divisions. Two seat car divisions. There is not going to be a restriction on weight ever. Basically run what you brung for now. The vettes and Cobras will battle as always in a two seater class if ever initiated. Now that I have mixed up the works, see you at the races One added note: the autocroass was started on the basis of a street car driven to show and runs. I personally don't care either way. I know I cannot compete with a lot of the cars. I don't even have the correct tires let alone a suspension set-up. Enjoy and love 3170 kicking some arse's Gary

Thank you that is great news, we heard a slightly different story. Several competitors got together and asked Ed to have the minimum weight rule. We were told that there was a strong possibility that it would happen by a source close to Ed. I have heard that lots of people were contacting Goodguys telling them not to do it so what ever happened I am a happy camper!
Incidently my car is legal for street driving in California and has plates and insurance I don't drive it on the street because of the danger from other drivers.

The 2018 plan was as follows:
Form circular sections of mallory metal or lead with the same OD as my frame ID with clearance for sliding. Slide a bunch of weight into the rear 5 feet of both frame rails and then make up spacer tubing that butts against the front caps and keeps the weight in place. We would have a really low CG, 59% rear weight bias and probably be able to use more throttle on them.
I think the car might actually be faster because 200 TW tires need weight to achieve maximum mechanical grip. Not doing this will save me a bunch of work!

[cycleguy55]

Originally Posted by Cobra #3170

The 2018 plan was as follows:
Form circular sections of mallory metal or lead with the same OD as my frame ID with clearance for sliding. Slide a bunch of weight into the rear 5 feet of both frame rails and then make up spacer tubing that butts against the front caps and keeps the weight in place. We would have a really low CG, 59% rear weight bias and probably be able to use more throttle on them.
I think the car might actually be faster because 200 TW tires need weight to achieve maximum mechanical grip. Not doing this will save me a bunch of work!

It could be faster - as long as you aren't doing wheelies half way down the course! Just like the old Hemi Under Glass and Little Red Wagon exhibition drag cars.

[hinoonaz]

I am glad you won't have to add the weight. Mixed emotion I am sure. Probably would hook up better and of course faster ! The Vettes and Novas shooting themselves in the foot I suspect. Hope to see you in Scottsdale.
Gary

[Cobra #3170]

Originally Posted by hinoonaz

I am glad you won't have to add the weight. Mixed emotion I am sure. Probably would hook up better and of course faster ! The Vettes and Novas shooting themselves in the foot I suspect. Hope to see you in Scottsdale.
Gary

Thanks Gary,

We will see how it runs at Pleasanton tomorrow, if everything goes well we will be in Scottsdale next Thursday. I am just getting ready to load it now doing final clean up.

[hinoonaz]

Good luck

[Morris]

Bruce

Adding weight and Torsional Strength is not all bad.... That was the reason we built this plate for KMP259..... and it works .... like closing in the back of a bookcase.... with the sides and shelves it's very wobbly but the minute you put the back cover on the back of the book case .... then it get's very rigid...
The suspensions starts working like it should.