Rear end ratings. - Page 2

G.R. · #21 (**permalink**) 07-08-2005, 11:58 PM

Not being a smart arse here but how many actually drive that 6-800hp , radical cam, 90'' wheelbase car at the speeds the motor/drive train was designed for frequently, if ever on the streets? Be honest if you own one of these do you take it to get the wife a quart of milk or eggs or come home from a bad day at work and take it out for a little spin?

I've seen a lot of of 6-800+hp cars, not just Cobras, that look awesome, sound mean and nasty but are rarely street driven. Why?, because they are a handful of nasty and generally don't run well at low RPM. and most of them are either trailer or garage queens.

I like my mild little SB that I can drive where and when I want. Yeah it'd be nice for the ol' ego to having a thunder thumping monster under the hood..... but reality is different if you want a driver not just a showboat or 2 or 3 times a year track car.

But each to their own and more power to you.

Excaliber · #22 (**permalink**) 07-09-2005, 12:32 AM

I hear that G.R.

Exactly why I "down sized" my motor from a "dragon" to a mere "beast". I actually DO go to the store just for milk now.

RICK LAKE · #23 (**permalink**) 07-09-2005, 05:37 AM

G.R. There are some cobras out there that make an honest 700 hp but the tork is maybe in the 620-630lbs. There are a couple of twim turbo motors and blower motors that are in the 800hp without any trouble and street driven. With any supercharged motor you don't need .600" lift cam to makes these numbers and with a turbo they sneak up on you and you never hear them coming. Read the article on John Meany corvette. I talked to him, 1200hp and 900 lbs with small turbos, destroked 400 chevy motor with a .550" lift cam. Wouldn't say the other specs. With a good FI system all the problems are a thing of the past, cold starts,flat spots,running toorich or lean. NO KNOCKING and the list goes on. The exhaust is why you don't see more or these setups in a cobra. The rumble is not there, but the power is. SB are fun, on a small track they can outrun any big block. If you build a motor with the right parts and have GOOD GAS, there is no reason you wouldn't drive a car like that out on the street except in jersey because they get hit by stupid drivers that can't drive to start.

I would not go on a 500 mile road trip with a 700hp motor, fuel cost is one and depending on gearing and comfort is the other.

Rick Lake

Rob_R · #24 (**permalink**) 07-09-2005, 09:26 AM

GR,
My SPF with a Keith Craft built FE motor has the sort of specs you are asking about. This car is only street driven. I only put a couple thousand miles a year on the car. The low milage is a result of NJ regulations and the winter weather. This engine is very street friendly. The motor starts easily hot or cold and, if necessary, it will idle in traffic all day long. The motor doesn’t like to cruise below 2,000 RPM so I use the appropriate gear. I use 94 octane Sunoco and no octane boosters.

As for your first question – do I drive the car at the limits of the drive train/motor on the street? No way! I need my drivers license and my life. I do occasionally stomp on the loud pedal on a deserted piece of tarmac. That is all I need to satisfy my horsepower/adrenalin rush. Plus this activity helps blow out the garage dust.

I have driven this car for 200-300 miles in a day without an issue - other than fuel prices.

Yes you can have a high horsepower, street friendly motor.

Robert

chrispy · #25 (**permalink**) 07-09-2005, 02:28 PM

OK I did not want to start a duel in here with this question. Other than that, a lot of good advice!!!! THANKS TO ALL.

Robert Sharpe ,

Thanks for the informative details. I agree some type of solid 9" would be the way to go. Like Excaliber mentioned, I am trying have my cake and eat it too. I do know going with an IRS that are currently offered in most of the kits will not really handle the power. Problem is logistics of getting something else in there. There is enough to worry about with a kit car in itself, and not really looking forward to adding or changing something as the rear-end / suspension setup. I am really stuck on the IRS, and I might take a bullet later on it.

Excaliber,

The street tires you list is pretty much what I had in mind. Just a different opinion of "street" I guess. Or should we call them "Barely DOT" tires. Yes the 3:31 ratio was what I was thinking of...... just did not want to spit that out and have to put my fire suit on (getting flamed for it).

As far as streetability!!!!!! I am trying to keep it a "very enjoyable street car". In no way am I going over .600" lift. I had drawn up my motor on paper and Dyno, and then KC came along with this post KC 710hp beast . Almost exactly what I was working out on paper. Now granted I am not going to run 10.5 comp, especially with the supercharger.

Nor am I going to run a .620" cam as well. I was at or around .560" with a low 4 to 6 psi range from the supercharger, still playing with those numbers.

Like Rick Lake mentioned above, The fuel injections these days are starting to make that much power pretty streetable, as far as what I have seen. With the FI I do think that this much power can be made very streetable. Than again, can the FI "detune" a .620" cam like KCs motor linked above, if in fact it was not streetable? I doubt it.

Might be very interesting to see how Al W finds the new motor once he gets it installed. Heck he is not too far from me (hint hint) , and I take orders real well.

Now if I was a smart person and lost the ego. I would put a Ford 302 crate in there, and have all the power that I would ever need. Something about the male chromosome that is making me build this stupid beast.

Rick Lake,

You mentioned something that I had never thought of. The exhaust note. Obviously with the FI it will be a little finer. But this concerns me as it is taking away from the ego factor. Now I have never heard a FI BB exhaust note from a Cobra exhaust yet. This should be something that I need to look into. For those that have heard it, how far off is it???? God forbid if it sounds like a sewing machine, like some of the rice burners sound these days. I am sure it is far from that, but how far off is it. Maybe Al W could chime in when he gets his installed.

Getting back to the rear-end at hand.

I might just stick with the current offerings that the IRS kit builders are offering. Cross my fingers and hope it breaks well after I have recovered financially from building the beast. Better yet, hopefully it will break in fall, and I will have the winter to work it over.

Chris

chrispy · #26 (**permalink**) 07-09-2005, 02:55 PM

Terry,

That Tom Banard you mention. Could that be spelled Tom Burnard by any chance? If so that is my lost cousin out that way.

Chris

Excaliber · #27 (**permalink**) 07-09-2005, 05:17 PM

Exhaust note:

Now THERES something I KNOW about! With the 12.5 to 1 C.R. I used to have; with open headers the exhaust was litterally ground pounding, earth shaking, grand stand rattling LOUD! It was tolerable (just barely) with the side pipes on. I wore ear plugs MOST of the time and ALWAYS with open headers. I entered a rumble contest once (open pipes) and as the crowd gathered around they watched as I put my ear plugs in BEFORE I even started it!

When I DID start it the crowd moved back and everyone covered their ears when I "wrapped it up". Mothers grabbed their screaming babies and ran for cover.

Now I've got 9.8 to 1 C.R. No comparison, the exhaust sounds great, but can't hold a candle to the massive sound of a high compression FE. Think "cannon" times 8 cylinders.

chrispy · #28 (**permalink**) 07-09-2005, 05:27 PM

Excaliber,
Too funny.

You failed to mention if you won??? Or is the tastes these days the sick sound that the rice burners are producing. LOL

Than again, I do hope that some of the rice burners were in the same contest, and you gave them some good education.

Chris

chrispy · #29 (**permalink**) 07-09-2005, 05:30 PM

sick = terrible

Excaliber · #30 (**permalink**) 07-09-2005, 05:36 PM

Won? Hands down, "blew" the Judges away (and half the crowd scattered). 1st place without even hearing another car.

This year? They wouldn't even let me enter again! They REMEMBERED my car. I tried to tell 'em it was different now, they didn't even want me to START it to prove it.

chrispy · #31 (**permalink**) 07-09-2005, 05:43 PM

Excaliber,

Maybe a good excuse to change the color of the car, and put on some disguise.

Or are they banning all Cobras, in favor of the rice burners? Please tell me this is not so.

chrispy · #32 (**permalink**) 07-11-2005, 02:06 PM

Update.

Well I have this issue sorted out with one manufacturer. They sell a kit with the car, that deletes the parts that I need to beef up. Still waiting on word from the others. Take a guess on which manufacturer got back first.

So in working up my build sheet, I need to find a Dana 44 pumpkin and related parts (i.e. gears, spider, LSD).

One of the parts I am having trouble with would be the half-shafts (or whatever you call them). The 30 spline to yoke things that come off the pumpkin.

Was told that the resources above were the way to go. Anyone have a website, or contact info on them.

Thanks in advance,
Chris