Road Racing a 01 Cobra. What I have, What I need.

[isrboss]

I'd be curious how this works out for you. I think A1yola was running 4.10s and he seemed to like them IIRC

For me, I'd rather not have to use 5th for the following:

• With me strapped in and my short arms, 5th is a long throw.
• Just another shift I have to make - my philosophy is the least amount of driver input results in the least amount of potential error

I feel confident a 4.30 rear will be great for a NA 96-01 Mustang/Cobra. These cars have low tq/hp motors, and unless you plan on power adder or a built motor gearing will be your last worry as you will likely be fighting heat. Once I looked at the gearing I knew that it had to be at least 4.10 back there. Any car achieving 70mph in second and 100+ in third with a 3.73 rear is ridiculous. I know that 5th is an over drive and has a big gap from 4th, but I feel like it would be better to grab 5th at 120mph (4.30) instead of 140 mph (3.73) to minimize the aero drag while building power in 5th and allowing 160mph to be obtainable(on Daytona).

Also a lot of tracks will not give the opportunity for a 3400lbs 270 whp to see over 120mph. The acceleration on corner exit will be sick, the problem will be getting it to the ground.

 

[LargeOrangeFont]

?.. the problem will be getting it to the ground.

Yes.

4.10s I can see. 4:30s may be good in some edge case tracks with a 5 speed. I can see this being more viable with a 6 speed.

I'm not saying it won't work, it just won't be optimal on very many tracks. Doing a gear change on every short chute is giving up time. Build the car to get through corners as quickly as possible because that is where you spend most of your time.

 

[WutApex]

I've actually thought about 4.10s since there are a couple places at our three local tracks that I seem to be right in between the sweet spot - either lug it a bit in 3rd or bounce against the limiter in 2nd. And I would like to see if I could pull out of slower corners a bit quicker. I'm sure that a gear change would result in not being the the sweet spot in some other corner though.

Going with 4.10s, I think I'd only have to go to 5th on one track when I get up to around 125-130 (I think).

 

[isrboss]

I really don't think the shifting will be a - impact. You will be mostly just moving up from 2-3-4 to 3-4-5. I would think the lugging on corner exit will be just as bad if not worse than a shift up. Plus lugging some on a 4.10 or 4.30 would be over pretty quick, versus a 3.73.

I agree it is about corner balance, but the sn95 is no bullet through the turns. I have come to terms that braking and corner exit is my goal.

I currently have a 2013 Boss, and although it is setup close to neutral in the corners, it gets out of the turns great. On 3.73 with the Getrag MT-82 the gearing is close to a T-45 with 4.30.

 

[99COBRA2881]

I paired 4.30s with a t56 in my '99 cobra. Its a fast track car for what it is. The tracks around here are all short tight tracks for the most part. The short rear end gears worked great and left me rowing 3-4 for the most part and downshifting to second only on the slowest corners.

 

[JTStreet]

I'm most definitely going to report back on this once I get the car on the track, and let you guys now how the 4.30's perform, and whether or not they're a good fit for this type of application.

 

[TXPD]

if the op is from sc, that gearing might be ok at Carolina Motorsports Park. At the other tracks near, Road Atlanta and Roebling Road, it won't work.

I run a 4:10 with a 7k rpm redline. I am near the top of 5th gear at the end of the 145mph backstraight at Atlanta and front straight at RR.

personally, if hpde is all this car is for, there's no stress to maximize its speed and handling. the car is for fun.

maybe its just me, but I don't race at 10/10th til its time to go for the money/trophy. I don't come close in practice. in a de I am out for fun. nobody should be driving 10/10th in a de.

 

[isrboss]

if the op is from sc, that gearing might be ok at Carolina Motorsports Park. At the other tracks near, Road Atlanta and Roebling Road, it won't work.

I run a 4:10 with a 7k rpm redline. I am near the top of 5th gear at the end of the 145mph backstraight at Atlanta and front straight at RR.

personally, if hpde is all this car is for, there's no stress to maximize its speed and handling. the car is for fun.

maybe its just me, but I don't race at 10/10th til its time to go for the money/trophy. I don't come close in practice. in a de I am out for fun. nobody should be driving 10/10th in a de.

What is your overall tire diameter when you're about to max out 5th at 145mph with 4.10? If you stay close to 26" overall diameter, you should be 178ish at 6800rpm in 5th on 4.30.

 

[TXPD]

we run 285/650-18 slicks right now. at Daytona I was using 6th gear and not quite getting to 170. so...180 in 5th isn't happening.

 

[Ruslow]

4.30 for that track may work but is that the only track you plan on running?i think I would give up some seconds on one track to be faster on the other 3 I plan on running.IF you are going with that gear set and the sessions are longer than 20 minutes I would look at a diff cooler.you are spinning that set fast and the pinion bearings are really covering surface area.I had a temp guage on mine and after 15 minutes with 3.73 I was up to 160 and that was a solid axle with 2.5 times the lube cap.A locker would help with temps but a clutch system would be worse.Stan

 

[isrboss]

we run 285/650-18 slicks right now. at Daytona I was using 6th gear and not quite getting to 170. so...180 in 5th isn't happening.

Well there's the difference the OP should still have the oem T-45 transmission which is a 5 speed. It sounds like you are running a T-56 (magnum) 6 speed.

 

[_MrK]

I almost avoided commenting because there are several of these threads already in this forum. But, it is sleeting and I am sitting here so what the heck.

Swap the brake pads now. One of the worst feelings on the track is hitting the brakes and nothing happening. Better off wasting the $50 of HPS pads you have left.

I don't really think your car is built for a road course, but neither was mine when I first started. Just make sure it is reliable and safe. Before and after each event inspect the cars suspension and brakes thoroughly. As your skills improve you'll need to make changes.

When time comes for a new K member I would go with MM. I did use a UPR K member for several years and through HPDE3 on my Terminator. Most people thought I was crazy, but I checked with UPR and inspected it every event. UPR said it would be fine and it was.

I know there's only a 2 by my post count, but just wanted to back this comment up as well from personal experience with the HPS and HP+.
Being new to the track, there is a good possibility over-braking will be a factor for the first couple events. That said, even a step up from the HP+ would be worth looking at. The general rule of thumb is if you stick to the same manufacturer, you will not have any bedding issues switching from street to a more aggressive pad. Which means you can keep your HPS for the street and switch in something like a DTC 60 for the track. Oh! and change your fluid, listen to your instructor, and don't drag race the Miata who's passing you, he'll be out of your way in a couple turns.