Mr. Wizzard

I'm in the process of building a Grand Sport with Mongoose Motorsports. I've wanted one since I first saw them race in 1964. Had an opportunity to buy a (used-up) one in 1967 for $3K, but my Father wouldn't lend me the money to buy that "flimsy pos".
I've never let him off the hook on that one....
I should have my car here (at Endyn) in October and we'll finish it out with custom stainless headers/side pipes, and a host of other special pieces. I'm very much looking forward to it, as the primary focus of our business has been Honda racing engines for the last 10 years.....

jim lockwood

Welcome. You ought to have a lot of fun with your GS when it's completed.

There are several GS owners on this forum, most of whom just lurk until the subject of a Grand Sport comes up. You can see who most are by reviewing this long running GS thread:

Grand Sport link - click here

How about posting pictures of your build up to the existing thread?

Jim

vstol

Mr "Wizzard" where do you live as Jim says there are plenty of GS's to look at

Mr. Wizzard

I live in Fort Worth Texas, where I've operated a small company (Endyn) since 1974. I specialize in cylinder head design, and over the years Fords in Nascar and ProStock were the recipients of our products. I retired in the late eighties, only to be turned on to Honda's and today we supply engines to Honda R&D, as well as independent racers all over the world.
Despite all of this (and having owned a real 66 427 Cobra, as well as many rare Fords), the Grand Sport memories have remained permanently etched in my mind.
I'd entertained buying a D&D, but the demands at business gave me little time to act, and they apparently disappeared. Several years ago, I looked over the GS that Alan Sedvadjian (who owned the car I could have bought years before), and the fire to own one was rekindled.
Around this same time I saw the cars that Mongoose was building in several kit car magazines, making another option possible.
A couple months ago, I went to Duntov Motors in Dallas to look over their cars and facility. I saw the molds they purchased from the company that restored one of the original cars, and inspected pretty much every aspect of their offerings. We also discussed the Super Performance cars that are supposed to debut the end of this year.
A week later I flew up to visit Mongoose Motorsports. I felt their facility was well laid-out and everything looked in-order. They had a number of cars on display that appeared to be very well detailed. I drove a couple of them and was quite impressed...in fact their 390HP LS powered car felt a lot stronger than the new Z06 I arrived in! There were also no creaks and groans I'd long associated with earlier Vette's.
I particularly like the fact that the Mongoose cars don't rely on the early geometry suspension that was largely responsible for the original car's evil handling.
They gave me an opprotunity to pick the material grade and thickness for the chassis, the number of plies in the body, and essentially build what will be my notion of the ideal Grand Sport for my driving style.
I placed an order and gave them a deposit on the spot to get going on it.
The car will be built in the spirit of the originals, as light as practically possible, solid white for the color, lexan strap-up side windows, original-style interior (I'm having Classic Instruments replicate the stock GS instrument cluster), and as I mentioned before we'll build the final pieces here when the car arrives. Initial power will be a GM crate LS3 with 480HP, but we will begin building a 650-680 stroker combination with Kinsler cross-ram over the winter. The only amenity the car's coming with is a heater defroster.
So, there you have my plan. I'm about as excited as a 61 year-old can be, and thinking about it has definitely proved to be a distraction from my work!
At any rate, I hope that I can discuss these cars with other enthusiasts here, and as soon as it arrives (the end of October), I'll see to it that there are plenty of pictures.

Larry Widmer

keystonefarm

Hi Larry, Ken McCorry here. Owner of D&D chassis #049. Lots of great people and info here. I'll be 61 this November and I almost ended up with Winterstein's car back in the late 60's !!! I know how you feel !!! My deal would have been for $5500 !!!!. Hindsight is always 20-20 .
Jim Lockwood is a treasure trove of info as are others who have built multiple GS's. Welcome to the group !! ------- Ken McCorry

groovyjay

Nice to hear from another GS owner. I'm building a 63 GS Roadster. Hopefully it will be drivable next summer...

Mr. Wizzard

Last night, I spent a couple hours going through a portion of the thread Jim mentioned. What a great resource.
I had no idea that there were so many replicas out there. I'm wondering if there shouldn't be a web site specifically for these cars where owners and builders can discuss the nuances of their individual projects?

aworks

I don't own one anymore but I built one roadster and one coupe. I do miss them both but they do have great homes now. You will find there are a few GS guys here that are willing to help you out.

Brian G.

These where my cars.

Mr. Wizzard

Beautiful cars...... Had I found this place years ago and seen some of your cars, I wouldn't have waited this long to move on one.
One thing I don't like on the Mongoose car is the wheel spacing, however, over the winter, I'm going to take a hard look at what I will need to do to narrow things up, so a wheel with deeper off-set will work. I will also be looking to go to a different wheel size so tires that are more "scale" will be available. There's not much out there for the 17 inch wheels from what I've seen. The rear tires are as short as the fronts, and there's way to much wheel well in the rear for a tire that's only 26" tall.

jim lockwood

Um, sort of a "misery loves company" thing?

I believe the Mongoose cars attach the C4 suspension at its original, design width. That produces the wide wheel spacing you noted. It's a big job to narrow the suspension without screwing up the geometry.

At the front, for example, you'll need a custom-dimensioned steering rack, correctly positioned.

At both ends of the car, a bump steer gauge will be your best friend.

Not following you completely here.

If you are looking for performance street tires, 17" wheels aren't far from the "sweet spot". The difficult problem is coming up with performance tires in 15" diameters and appropriately scaled widths. You end up going with something like vintage Goodyear Blue Streaks or Hoosier TDs, neither of which are street legal.

Although I do understand what you mean about too much wheel well showing, I'm surprised you are encountering this with a 26" diameter tire. We run tires that are 26.5" diameter on our two cars and they fill the wheel wells nicely.

I just took a look at some representative pictures on the Mongoose web page. To my eye, the tires mounted on their 17" Cobra-styled wheels look to be shorter than 26".... maybe even less than 25".

Good luck,
Jim

Mr. Wizzard

The largest Sumitomo 315/35x17" tire for the rear is 25.7" tall. The fronts are the same height as well. The only other tires available are Michelin's and they are the same dimensions.
I'd be more pleased if there was a 40 series tire available for the rear, but the last company to meke onw was Goodyear, and they aren't available anymore.....
Larry

jim lockwood

Let's take one step back.... How are you going to use the completed car? Street driven only? Dedicated track car? Both street and track?

Jim

Mr. Wizzard

Mostly street, but I could take the car to the local MotorSport Ranch for a spin once or twice a year. Our schedule here doesn't afford me much time.
For what it's worth, I run RA1 Toyo gumballs on my Honda's, so high tread wear rates don't bother me.

jim lockwood

If you have the option of running 15" wheels (and the only near-correct reproduction GS wheels available are 15"), BFG TA Radials are available in wheel-well-filling sizes for street use.

On the rear, a 255/60-15 at 26.8 would look about "right" as would a 235/60-15 at 26.1 on the front.

For track duty, where "period" appearance is less important, a 2nd set of wheels, say in 17" diameter, could be fitted with the Sumitomos, or Nittos, or Rikens or..... well, lots of options here.

Jim

Mr. Wizzard

Are the reproduction GS 15" wheels available in the correct offset for use with the (wide) C4 suspension?
In reading through some of your exploits, I saw that the shifter was repositioned. So, if I use a T56 transmission, will the shifter have to be located rearward from where it was in the original cars?
Thank you for putting up with my lack of knowledge on these subjects.
Larry

jim lockwood

The 8" wide front wheels are, last I checked, available with 4" backspacing only. For these to look "right", you really need to narrow the front suspension (and deal with the problems of re-establishing correct geometry).

The 10" wide rear wheels are available with either 4" backspacing or 6" backspacing. The 6" backspacing would look approximately "right" with stock width C4 rear suspension.... i.e. you won't have a significant "Dumbo" effect. If you want the more period correct deep dish wheel on the rear, then you'll need the wheels with 4" backspacing and you'll need to narrow the rear suspension.

It's my (unverified) understanding that the early C4 rear suspension (early == '84 - '87) is slightly more narrow than the late suspension due to the way the rear caliper mounts on the hub support. So, if you use early suspension on the rear and narrow it, you could use the dished rear wheels and they would look spot-on "right".

One thing to know..... if your front brakes include the late 13" rotors, you can NOT use 15" wheels. To use 15" wheels, you can run the stock 12" x .8 rotors and matching calipers or you can get creative and adapt other calipers and rotors to fit within the available space (see the earlier thread for examples of how this is possible).

The aluminum reproductions of the original magnesium Halibrands are available from PS Engineering in Torrance CA.


The shifters in both our cars are in the stock location with respect to the transmission tail shaft housings. It must be someone else's Grand Sport that has a relocated shifter. If so, they can chime in about the issues of relocating it.

Our two cars run oldde fashioned 4 speed transmissions, one is an M22 Muncie and the other is a Richmond Super T-10. So, I really don't know anything about adapting 5 or 6 speeds to these cars.

Just as an FYI, the over-arching theme in the preparation and presentation of our cars is period correctness and ultra light weight.


NOT a problem! Everyone starts somewhere.

10 years ago, when I was just getting started with our first GS and trying desperately to figure out what to do, John Hinckley gave me some valuable guidance.

I'm just paying it forward.

Regards,
Jim

Mr. Wizzard

Thanks Jim. I will go ahead and receive the car with the knock-off style 17" PSE wheel / tire combination. This winter, I'll take a hard look at what we might engineer to acheive the look and handling I want.
While my engine isn't the traditional small block (or big block), weight is an issue with me as well if I want the car to represent the spirit of the originals. Remember that with Honda's, weight is everything in my "functional is beautiful" world.
Thank you once again,
Larry

Sam Kalmuk

Larry: It's great to see that you are also bringing the Grand Sport to the forefront by getting one built the way you want it. My GS Wintersteen replica was quite the task, but it is now on the street & I'm driving it. With fellow GS guys like Jim Lockwood around, we have a wealth of talent, knowledge, wisdom & understanding, to share info & help anyone who undertakes such a grand project. Welcome to the world of Grand Sport.
Sam

Mr. Wizzard

Hi Sam. This web site has been a great "find" for me. I can't tell you how much I'm looking forward to getting the car down here so we can begin building all the finishing bits and pieces.
Two of our Honda engine customers from Canada are in town visiting right now. They (along with the others I've discussed the GS with) think I've flipped out......and I suppose I have!
Larry

mikey

Mr. Wizzard..
A friend of mine in Dallas has a GS replica, i can link you up if you'd like.. another friend of mine in that area goes out to motorsport ranch from time to time..

PM me a number or email and I'll pass it on.