Im sorry for opening my big fat mouth... for some reason I thought you had a FFR. My humble apologize to all...

David

PS... I still say.. unless you are really experienced and your car is FULLY sorted, stay away from the locker and spool :D

David,

They are some big numbers for wheel rates, but they seem to work quite well in your chassis. (JBL standard rates: 165 front and 145 rear. But roll rates are adjustable from 80>1200 front and 40>650 rear.)

Also very high frequencies, I bet it is hard to get the dampers dialed in as your shaft motions are very small but speed high. I always found that valve flutter was a problem in these areas. Hard to keep the damper fluid from cavitating.

I am also surprised that you guys cannot run anti-roll bars. But I guess it does lower cost and leaves you only tire pressure as fine adjustment, therefore making setup a bit easier.

The traction-lock is the standard diff in the JBL as well. Works pretty well. The only problem is lack of adjustability and the sensitivity to heat in the slip percentages. Should work great in your spec FFR. With the power levels in the stock engine, you will not build too much heat.

Craig,

I never got to drive one of the Reynolds engines. Just a 427 in a Lola t220 and a 454 in the M8. Still plenty of power, just not in the leaque of the 510. I wonder what the asking price was for that M8D? (Well, I guess if you have to ask, its out of reach anyway!!!!!)

http://www.mathewscollection.com/sale_race_M8D.htm $200K. It was $240K a few months ago. I know they had a couple of M8Ds.... I think this might be their lower spec car. They also have an M1B and an M8F for sale !!!!!!!

Craig...
I never received your e-mail!

DV

DV - that's a shame! You're probably thinking that I'm too slack to make the effort to reply to your fabulous offer, but I really did send one to you! I've resent it ( cobrabildr@aol.com )

I'll PM it to you as well - just to be sure.

Thank you,
Craig

Ooops!
I've gotta change that e-mail address!

DV V10cobra@aol.com

Richard,

Sorry for the delay in replying.

From what I have read, the freq's are inline in the front, quite high in the back. However, I realize, there are 2 camps. One is soft springs and stiff bars, the other the oposite.

As far as shocks go, you are probably very right concidering the shocks are not mono tubes and the pistons are quite small in the pro-shocks and they are fixed valving.

When I have more time, I'll shoot you some questions if you are interested in chatting about it.

David

Torsen available from Ford Racing
 

The Torsen differential has been available from Ford Motorsports for a while now. M-4204-T28 for 28 spline and M-4204-T31 for 31 spline.

This has been my only choice in a differential since reading Carroll Smith's evaluation of different ones years ago. And now Ford has them at $499.95 list. Net much less.

Rated by many as the finest torque sensing differential in the world. No clutches to replace. Great power application.

Can't go wrong with that.

Spools, Lockers etc
 

I race a Cobra Replica producing around 700HP, and have a 9 inch rear end converted to independent suspension (ie no longer live axle). When I first raced the car it had a spool, which eventually let go by dropping the crown wheel off (at low speed thankfully). To get the unit apart, we had to cut the spool apart to save the axles, as the axles had twisted solid into the spool, or in fact the spool had twisted onto the axles. I guess this may relate to the breaking comments by other members about spools?

When rebuilding, I decided on trying a limited slip differential. I am not sure if this type is what you Americans call a Locker, but it is not an immediate lock, rather it uses clutches. I was advised that this may overheat and burn clutches, so I use a fully-synthetic oil, and so far it has survived. I have also installed fittings to allow the use of a cooler, but havnt installed the cooler yet.

As for the best result for racing, very little difference, i think that the limited-slip unit has been smoother, it still always spins both wheels, so definately isnt slowing me down due to one-wheel spinning. On the street, and pushing the car around the garage, the spool was harder to move, whereas the limited slip has a little give.

I hope that helps

Cheers
Bevan Wright
Wellington - New Zealand

Me and rear clutch packs don't get along....I've broken every one I ever had. Next setup will be the Torsen.

Ernie

Bevan - I'm glad to hear about your car. This isn't it, by any chance?

http://www.clubcobra.com/photopost/d...22lift_off.jpg

Also, do you know the brand and type of oil in the diff? I can't say that I've heard of a synthetic diff oil, but I haven't really looked. I remember the last LSD centre I had, I just used Castrol LSX90 with the Ford SVO Friction Modifier. That's the worst smelling stuff I think I've ever come across!

Yes - that is my car, a good guess, where did you come across that photo?

The oil I use is a Castrol fully synthetic limited slip oil called SAFEX (not sure of the spelling but sounded like that). That too is an incredibly smelly oil, and costs more than liquid gold I think, but it seems to have done the job so far. I was advised to use this by a guy who used to help run the Tom Walkinshaw Race Car Jaguar XJS a few years ago, he reckoned that was the only stuff that let their diffs hold together too. The oil wasnt on the shelf, I had to order it from the Castrol head office to get it. By the way, if you are running a manual transmission Castrol also does a synthetic oil as well (but the name escapes me at the moment).

I would guess that the torque produced by a supercharged big block might be more than my car, so maybe thats why I have got away with it? My car is a full race 454 Chev, and I guess the power curve is pushed a bit higher in the rev range, and doesnt have the hairdryer pushing the air in.

Double Venom, If you feel that your diff needs to be put to the test, I am quite willing to give it a go!

To be honest getting any bits like that are very hard to get hold of in New Zealand, as all parts like that are floating around from imported cars from years ago.

The shipping costs for a diff head to New Zealand are probably horrendous!

What do you guys pay for a good diff head in the USA, in New Zealand we are paying up to $1000 (probably around 600US$), and thats a second hand part, nothing that flash.

There couldn't be too many highly modified BBC Cobras in NZ.... I don't know where I got the photos from - it was probably about 2 or 3 years ago though.

http://www.clubcobra.com/photopost/d...22liftoff2.jpg

The guy that built my trans was a Castrol Tech until very recently. I'll get him to organise so of the synthetic oil for me - thanks for the tip!


MMMmmm... nice brakes! http://www.clubcobra.com/photopost/d...t_off-1_1_.jpg

There are probably a couple of hundred Cobras running around New Zealand now, most made by the some company, but you are right, not many Race Big Block cars.

How far away from finished is your car now?

Mobil 1 makes a full synthetic diff oil. Still need friction modifier. Several Mfg,s make synthitic ATF for use in T5-Z's, and Tremecs.