What's up with all the 289 activity lately?

[Rick Parker]

David you have a PM

Rick

[Allan A]

IMHO KMP Aluminum 427's do not out handle a leaf spring fiberglass FIA.

[Allan A]

coming from behind

[Allan A]

See yea!

[David Kirkham]

Allan,

I have not doubt there are a lot of guys on this forum who drive so much better than I can that they could pass me in one of our 427 cars with their Pinto!

David

[PatBuckley]

Allan- tell the rest of the story....that was Ricks first time out!

[Allan A]

Pat,

Yes, but it was the only photo line up I had.

[TimG427]

"With their Pinto" I love it.

[Cal Metal]

David:

The interest that you have received for the 289 is quite a departure for Kirkham Motorsports, I would assume, based upon what you have seen in the past.

A couple of observations. Given the cost of basic materials these days, I would have to assume that many manufacturers are raising their prices, accordingly. Good 427 OEM engines are getting real scarce and they have always sold at a premium. This brings the cost of getting into one these cars at levels that we have probably not seen.

When we built the few Unique cars we did a few years ago, we could build (professionally) a 289 for under $3,000. That included the builder providing the used block and heads. Everything was new in the motor except the rods (reconditioned the old ones) and the crank (ground and balanced), if needed.

I know that Unique has finally put in a price increase due to the cost of steel and resin. I don't know what we could build the engine for today but we used to be able to do the complete car for around $34,000. I would suspect that that price is close to $40,000 now---and that is for a SB car. I think the 427 concept has become a very expensive one for many "would be" builders.

Perhaps, the results from the Russo and Steele auction with the sale of the Factory Competition car has renewed interest in the FIA concept. Who knows.

[Cobra Pack]

David,

How much is the upcharge for the leafspring suspension (I know you have been debating this for a while). We want a leafspring street car next after the FIA is done.

Do you have spline drive spoke setups for the street cars?

Thanks,

Mike

[David Kirkham]

Cal Metal,

I think you are correct. The cost of the 427 engines is out of control and I think the small blcok is a very valid and cost effective way to get into one of these cars--especially our latest lightweight cars where you can get blistering performance by way of weight reduction. F=MA as they say. You can always put in a fire breathing monster at a later date.

Mike,

There is no upcharge for the leafsping suspension right now. There is an upcharge for the original type tubular suspension, forged uprights, and Girling reproduction brakes. The upcharge is considerable ($15,000) as the work involved in making it is quite difficult. We only sell 1 or 2 of the original type suspensions/year so you can see it is quite difficult and expensive for us to make them is such small quantities.

In the past, there have been some misunderstandings that our aluminum suspensions were more expensive and therefore and upcharge over the original type suspensions, but this has never been the case.

We have not worked out a spline drive for the street cars yet. I am sure some day someone will want them and we will have to start making them.

David

[Anthony]

Wow, $15,000 upgrade for the original spec tubular suspennsion over your billet.

If I remember correctly, I thought maybe the new CSX4750+ cars have a billet suspension/uprights ? Maybe that is one reason why they are cheaper than the fiberglass CSX4000 LV cars?

Interesting.


Dave K., have you made any leaf spring chassis's with the added tunnel bracing like the original coupes had, and the CSX7000 fiberglass FIA's have?

[David Kirkham]

Anthony,

Making the original type suspension is extremely difficult and time consuming to do correctly. Frankly, I would much rather prefer no one ever ordered an original one again—even at the current pricing. They are just that difficult to do. But, even so, we are currently making billet copies of the original calipers for those guys who just can't live without them and want to get away from castings. I can’t blame them.

It would not surprise me if the newest Shelby cars came with billet suspensions. I remember several months ago an engineer from HST was here in our shop showing us drawings of OUR suspension they had just reverse engineered...

He told me they copied the suspension off of Turk’s car. He expected me to be shocked while looking at the drawings. I just smiled and told him, "That suspension is about 6 generations old right now." (Currently, that suspension is about 10 generations old.)

David

[David Kirkham]

Anthony,

No, we have not done any further bracing to the cars. Only the Daytona Coupes had that bracing originally, (if I recall correctly).

The leaf spring chassis is terrible to drive on the street. Certainly, the car handled well on the track, but is was a handful. Most of us don't live our lives every day and want to take our wives, kids, with us occasionally as we go for drives. We just decided to side-step the entire frame and went straight to the coil sprung chassis for our Hybrid cars.

David

[Cobra Pack]

David,

You are making me very nervous to drive my car with quotes like "the handling is terrible on the street." I have riden in a worm and sector car and rack and pinion cars and the handling is fine - way better than a '60's Corvette. Many original cobra owners much prefer the handling of the leafspring 289's including the owner of the 2138 (Lemans Replica team car) who is building my engine. Although my car is only a repro, I much prefer staying correct on the suspension (i.e. leafspring). Each to their own I guess.

In looking at the suspension on my car, the uprights are billet, but the lower control arms are steel. Are you putting more billet pieces in the suspension now on the leafspring cars?


Mike

[What'saCobra?]

Smart move, David. Seat time tells the whole story. Plus a little common sense.

The only time cross-leafs were worth the grief was in the day; when it was the only way to race the car and driver/teams were locked into the cross-leaf system by homologation. But, i can see that some guys really want the original configuration for historical faithfullness. Not me. Give me the old shapes on the outside and ultra-modern systems underneath. Only way to go...IMHO. The fact that it is much cheaper is just simply a side issue...

To make up for a whole series of design compromises, stiffness ruled in the sixties, at least in Cobras. Big time stiffness. And THAT put a lot of stress on bits and the chassis, particularly for long distances, vis: Europe, Sebring. Which was why 'only' the coupes had the trussed tunnel. (Though i know of at least one successful roadster competitor in European FIA races that for sure has one under his alloy tunnel cover. i do not know for sure for sure if it is legal. Not likely the only one.)

Of course, such stiff suspentions couldn't stand up to the long term stresses of rough road courses like the Targa, could they?

Uneven dia anti-roll bars (fr vs rear) put larger axial twist on the already rather flexible chassis, but the bars were necessary (it was presumed) to improve turn-in, throttle-steering and predictability. Everybody (except Ken Miles) seemed to hate the dreaded body-roll; which is more demanding to manage, admittedly. Bob Negstead had lots to say about this unbalanced error. The truss helped control (reduce) that twist and keep the tire patch more orthogonal or at least closer to the intended negative camber...

Even the brakes were beginning to put larger and larger folding stresses on the chassis uprights (fr and rear.) The tunnel also reduced that tendency and reduced both shock binding, drive line universal joint stresses and heim wear, maybe...

In the middle sixties, Porche, however, was already well along with the concept of softer coil springs, lowered roll centers and intelligent shock design. So were many of the CanAm designs. of both over and under 2 liter capacities.

This M6B below, designed about 1967, in which i have several seasons of seat time, had great control and predictability; yet neither excess roll nor overly harsh ride. But, it wasn't designed in the late 30's, was it?

[David Kirkham]

Mike,

"Terrible" is in the eye of the beholder...or pants of the driver as the case may be. Certainly, there are many, many guys who don't mind the leaf spring chassis and it's bouncing down the road. The car is quite stiffly sprung just for the very reasons What'saCobra mentioned.

The leaf spring by its very nature is not very rigid in the foward and backwards plane. As a spring it tends to want to do funny things. But, you also have to remember, we are looking at this through 2005 eyes and not through 1965 eyes. Many things that were perfectly "normal" are completely unacceptable today in the car world.

There is NO DOUBT the car handled exceptionally well as evidenced by the many, many victories the leaf spring car racked up over time. But nice to drive on the track and nice to drive on the street are two very different things. I have heard many times that the 289 FIA car was fast in spite of itself. As I said, the cars are quite stiffly sprung and I am reminded of Mr. Chapman's famous saying, "Any suspension will work...if you don't let it!"

Shelby thought the 427 coil-sprung suspension was better because they used it on the later (427) cars. I imagine they could have used a leaf spring as Corvette did for years--but they didn't.

David

[Turk]

I don't believe it was an engineer from HST that told you about the reverse engineering of some suspension parts they took of my car. I believe it was Kris. I think I told him to tell you .It was no big secret.

Cut them a little slack, will ya'. So they tried to copy a few billet pieces. You copied the entire fricking Cobra!! Geez!

Turk's car was one of YOUR cars. It wasn't something Turk whipped up in his garage. I believe they were looking for some inexpensive (read cheap) suspension pieces for the $39,995 Mexico cars. The ones they took of my car to replace with Shelby suspension must have been laying around and they probably used them for a model.

I don't know what became of that experiment. Initially they thought it was not a very good design. They may have abandoned it. Apparently you too abandoned that design and went to on to generation 7,8,9, and 10.

I wish you had told me that when you sold me the car. At that time, (not long ago) it was the cat's meow. You priced them accordingly. It was , what a $7000.00 or $8000.00 upgrade? Today when you look back a year, you find them laughable?

When Ford comes up with a new F-150 they tell everyone about the improvements they made to the new model. They don't go making the people who bought last years model feel like turd, by saying the things you say when you make a slight improvement to something on your car.

Today the upgrade is the steel suspension, not the alloy? I am confused. That happens to me often when I read what you say and compare it to what I have heard you say.

You make a hell of a car. I wish I could be as charitable with you as a person.

TURK

[Lew Ledyard]

Originally posted by Turk


You make a hell of a car.

TURK

Oh my God, did Turk just compliment David K?

[What'saCobra?]

Cut them a little slack, will ya'. So, he shouldn't have gloated about their new designs quite so much. Pretty mild compared to CS for the last almost 40 years.

Any bright bulb knows that various materials strengths can be uniquely utilized with appropriate designs. It isn't like they switch back and forth from noodles to potatos and back just to confuse us.

Steel vs Alloy vs forged alloy vs billet vs forged steel vs paneled steel weldments all have advantages and disadvantages, depending on the design and materials particulars.

Viz: Early GT40's were steel, then alloy panels; all shaped differently.

More precisely:

(purpose)(weight)(strength)(materials)(Cost)
(fabrication limits)(service life)(style) = f(design)

Gloating, even with some humorous intent, certainly doesn't help reduce the ever-present buyer's remorse, of course.

But, then again, it is also hard to decide when to buy the 'latest' computer without feeling 'screwed' in about 6 weeks (or the next monday) after the much better design or price become available.