Supercharging a Cobra

[Melodp]

has anyone have any suggestions as to the type of supercharger I should be looking for that would fit in a standard cobra. I have a 302 Ford 5.0 lit. It is a 95 Replica.

Thanks.

[Gasman]

I'll notify homeland security to watch out for you. Sounds like you will soon be a terrorist.

[got snake?]

Look here

To blow or not to blow?

[Jerry Clayton]

We have been putting a lot of blowers on Mustangs with efi and tuning them either with Diablo Preditors or FAST systems. Call my son Corey at 630-365-6737 or email us and he can fill you in. He has Pro-Charger on 2004 4.6 gt and one customer has 302 in a 88, others on the Mustang Cobra 4 cammer,etc

The blowers have been picking up the milage down low and really come on as rpm pickup---the roots type are pretty positive from lower rpms and have more of a linear power curve.

I used to run the GMC 71 series blowers on our top fuel/funny cars but am starting to think about putting the pro-charger on the LS1 I'm putting in my Everett-Morrison with Corvette aluminum suspension.

Jerry

[Bryan TTM]

Magnuson makes a nice roots style unit with integral intercooler for SBF...i've seen several installed and running...with either Predator or FAST(better IMO), they'll make an easy 100hp without boostin the snot out of it...kits about 5k complete

[427 S/O]

Do it, then post pics............

[Mark O'Neal]

I like the Novi 2000.

But, considering what it does in my son's Mustang (454 RWHP @ 6#'s), it seems it would be frightening in a light car.....

[StormBringer]

I had a old B&M 144 blower on my shell valley. Lots of power, difficult to keep in a straight line at full power but still drivable.

I think I was near 550hp give or take 25 depending on how far from sea level and gas.

[Tony Aprile]

Nick from Classic Concepts has installed several Paxton Superchargers in Superformance Cobra's.
He has taken the Paxton 302 Muatang kit and has adapted new mounting brackets to fit in the Cobra's smaller engine compartment.
As tested with a Ford crate engine 351/385hp, it made 480 rear wheel HP and 570 at the Flywheel. My numbers might be off a few but there close.

Nick is now a dealer for Paxton and can deliver you a complete kit for a Cobra installation.


I attached pic's of a 351 installation.







Tony

[Bill Wells]

the real question is :

how long will that crate 351 last unless he has played with the innards to make them blower friendly.

been there done that, grenaded in 3000 miles > wrong pistons, too high compression for the boost... KABOOM.

it was sweet while it lasted, but not worth the repeat for me. if the engine innards are blower friendly, it would last a lot longer. the sound of that blower spooling up is awesome, like a F 16 jet on a fly by and it kicks you to the back of the seat at the same time. lift the hood and crowds gather. but it wont last if the engine is not right for it. bill

[Tony Aprile]

Bill ...that is truely the Question, how long will they last.....I quess that partially depends on there driving.

I know they all have Water /Methanol injection to prevent detonation.

The longer install is going on two years, but I don't know the mileage of these cars.

This past winter Nick put a paxton on a Roush 402 that started out 525 hp, I don't know the dyno numbers, only time will tell how these engines react will the boost in HP.

Tony

[Bill Wells]

Tony, IF the engine has been BUILT to be BLOWER FRIENDLY, then life expectancy is pretty good, assuming air / fuel ratio is ok and is on the fat/rich side.

but bolting a Pax onto a crate motor not tweaked for same. i know the outcome.

and mine was not driven hard, it was used but not abused and seldom saw a conservative red line as the blower moved that tach needle so fast it was shift-shift-shift .

damn, i miss that blower feel, sound and looks..but i like driving and not being towed .

b

[Tony Aprile]

Bill...was your cobra chassis dynoed ???

I understand your thoughts exactly about shortblocks being built for superchargers. I stand on the sidelines to watch the results of these supercharger additions.

I'll stick with the big block and two carbs.

Tony

[Jerry Clayton]

I'm new to this forum, but let me give you a brief self-interduction, I am the Clayton of the Keeling & Clayton California Charger Top Fuel and Funny Car.
The addition of a supercharger to an engine will pump in more air resulting in more power. The Crank and Rods must be able to take the added strain and if they are forged steel they will take an increase in power but probably for a shortened period between overhaul( can you say 4.5 seconds?)
The block should be a 4 bolt main, preferably with angled outer bolts.
If all the bottom end pieces are up to the task of taking the added stress, it is just a matter of lubrication, valve train(other threads indicate to me that there is a lack of understanding on this) ,cooling , mixture and timing control.
With the current crop of EFI engines and PCM's it is pretty easy to control the combustion process to keep detonation at bay. Diablo and FAST (fuel air spark timing) systems that are easily tunable, even via cell phone!
If the temperatures are controlled-coolant and inlet air-(intercooler) ,larger injectors are installed, and a control unit for the fuel and spark properly set up for the type of driving you do , there is no reason that you can't run an engine for 40,000-60,000 miles.

We have been doing several install/tuning of various centrifugal superchargers(Procharger installs, tuning some Paxton and Vorteck) on varied milage cars running from new Mustangs to 20 year old cars with 80,000 miles.We did one on a 92 6 cylinder Mustang that was converted to V8 from Crown Vic POLICE car that had well over 100,000 miles.

The power levels are awesome and the smaller engines get good milage.
A Cobra has plenty of room for the install and intercooler and you will find that a smaller supercharged engine will make the power you want, but still have nice cruising street manners.At the lower power levels it won't have the cooling needs that the big blocks need.

I would be happy to answer any questions you might have about the mods needed for supercharging.

Jerry Clayton
PS Did I mention that I used to live in Shelby's apartment building?

Jerry

[Mark O'Neal]

That is valid, given a desire for maximum performance.

But we ignore that advice all the time. The key is how much boost do you need to run?

I have a 347 in the kid's car, as I mentioned earlier. It is 9.0:1 C/R and has forged internals, because I could, it would be sufficient with a cast steel crank and an aftermarket through bolt style rod.

The heads are Dart Windsor Jr aluminums ported to about what a Twisted Wedge does out of the box (but I already owned them).

I did run a girdle on the 2 bolt stock 302 block, but I have no illusions. If I break the block (and I will not) that will just keep me from driving over the crank.

The motor was tuned by Steve at powertrain dynamics using the stock computer from a 1991 Mustang. It doesn't run lean, and it doesn't detonate.

On the motor, it makes 410 FWHP (I didn't check it at the wheels). At 6 lbs of boost it makes 454 RWHP (I didn't check it at the flywheel). The time constraints of doing magazine articles precluded taking the time, and I really didn't care.

Now, with a 3100 lb Mustang my boy buried the 160m MPH Autometer speedometer while putting a Porsche in it's place.

Just exactly how fast do you guys want to push these things?

My motor in my old Backdraft Cobra is an easy 200 MPH car. I was probably close to it with the 418.

I didn't post this to be contentious, or pretentious, for that matter. I posted it because spending 25K on a motor is nice, and it can be fun, and it is absolutely necessary in some applications. But most of us aren't in that category......

Most of us just have to make certain that it doesn't run lean, and it doesn't detonate.

Oh, and while I never lived in Carroll's building, he did try to buy my company once.......

[niles]

Two questions to the blower experts.
Not real interested in going the FI route, are there any big disadvantages using a carb?
Would you be better off using a heavily built 351ci than using a stroker 351? I have heard that the shorter stroker pistons are not well suited for boost.
NNeed about a 100 more!
gn

[Jerry Clayton]

It is not so much a disadvantage using a carb as an advantage using EFI with so much computer control.
If you are only looking for about another 100hp you can easily get that with 4 or 5 lbs boost and either a blowthru carb or better one in a pressure box. You have to balance the pressures on the float bowls and fuel regulator and will need a device for retarding the spark as the boast comes up. If you are only looking for a modest gain you can probably get by without an intercooler.
Your engine probably would be strong enough for the extra HP as you are now limited by airflow with NA.
With a LOT of boost, the pistons need to have strong ring lands and a full skirt, Piston oilers off the main webs as we put in our dual turbo engines help a lot also.

Jerry

[cobrashoch]

Jerry - I wouldn't put so much faith in innercoolers running a pressure box and a carb. Been there, done that. (for sale: Vortec custom built water to air innercooler for a 600cu/in motor, cost 1900$) The real trick for a street blown engines in pressure box situations I've found is to keep the temps in the top of the engine yet control the overall cooling engine temps. Pressure box situations are completely different, and note I didn't say better, but I believe that to be so. And this stuff is not in the standard hot rod books either.
Your correct, fuel injection does change all of this. And you are further correct that the engine should be custom built w/stronger parts to include the cam grind for blower motors, though time and again I've seen mild boost situations work long term with factory engines. I've found that most of the blower type guys on this site know this stuff, know and do this stuff. You see, Cobra guys are not your typical hot rodders I've found, a few even have a few dollars that they can spend on insane ideas.
Welcome to the site - and be prepaired to be disputed a bit, you see that's another characteristic of this Cobra crowd too.
Cobrashock

[Mark O'Neal]

Originally posted by niles


Two questions to the blower experts.
Not real interested in going the FI route, are there any big disadvantages using a carb?
Would you be better off using a heavily built 351ci than using a stroker 351? I have heard that the shorter stroker pistons are not well suited for boost.
NNeed about a 100 more!
gn

So, why are you not real interested in FI?

[Mark O'Neal]

[quote]Originally posted by Jerry Clayton
[b]With a LOT of boost, the pistons need to have strong ring lands....

The first part is not defined, however land width is normally dictated by the combination. We would use the space allowed to the best benefit, but I've seen a 30# boosted SB 400 Chevy live for four years with a .175 top land.

Would I do it in my motor...no, but

and a full skirt

Truss rings around the bottom of the piston are designed to maintain a pistons shape. Forging advances in the last 20 years have negated this. Some of the slipper skirted pistons are far superior to the full skirts, particularly relative to skirt wear.

Full skirt or slipper should based on the internal design of the forging and the ovularity designed into the piston, not on the use intended for the piston.

Although I grant you, personal preference weighs heavily as well.

Piston oilers off the main webs as we put in our dual turbo engines help a lot also.

I find these to be an interesting phenomenom. The Nascar guys use them too. I'm becoming convinced that the pistons lack of flexibility is the reason you need them.

If so, proper skirt design (ovularity) is the answer.

Not sure in your case though, as I haven't seen your pistons.