How I selected a GT40 - Long

After reading a few of the recent threads I wanted to share how we made our decision. I am a mechanical engineer with a reasonable automotive background. As such I must first state I do did not see any engineering from any manufacturer that would disqualify any product. Mostly it is somebody took a differnet approach and/or had diferent priorities. It is up to the individual to decide what is important and the find the manufacturer that performs those items best at the best value.
I began my search for a GT40 was just after watching the 1966 LeMans race, but things like growing up and school put it on hold. I did get a model (still have it) a couple of years later and fell in love with the "bundel of snakes". Fast forward to late 1990's. I seriously begin to look for a replica because the real thing is well beyond what I can afford. Not many available, at least I can not find much information other than H-M (more than real thing) and some company in New England. Again I put search on hold to start a new business. Fast forward to 2002 I went into my dealer and there was a poster of a GT40. I immediatly went home and hit google - GT40 and found this, actually the original, forum. I learned my dream was real. At the same time my son announced he wanted to become an automotive engineering and learn to REALY drive. So after a conversation with you know (if you are married) who we are off to the races.

This forum helped us look up a number of sources, ie:
ERA - great car and site downloaded their manual, very good design and excelent engineering. I was put off with delivery timing and cost of ZF transaxel.

GTD - This was initially my first choice. The design appeared very well thought out, interior was excelent and attention to detail (clip latching, interior). While I did get some response I was a little concerned. Base upon the information from the guys who had GTD's I was prepared to go to the UK to look at them.

CAV Space Frame - This looked like my solution, based upon the GTD, with improvements, built by a solid company and a great value. Got a copy of their CD and was ready to go, but they did not sell "kits" only turn key minus.

Tornado - Contacted them and they were very responsive, great value, but thought the interior was not up to the standard I was looking for, and we would still need to source a number of items.

DRB - About this time we had an opertunity to see Bill Bayard's DRB. Great car, very good value. The fit and finish was first rate. Based upon a turn key minus and value this was the first rate. But like CAV the DRB appeared best to be bought as a turn key minus, as a kit there were still a number of parts that needed to be sourced.

GT40 Replication New Zealand - to me this was the low cost alternative. Apeared to be solid but I wanted something other than fiberglass for interior panels and was willing to spend a bit more for more upscale product. Again all the bits were not included in the kit.

CAV Mono - A very good looking car and very well built. Interior is excelent, but I found I would have designed a couple of the sub systems diferently, ie the rear clip is supported off a suspension attachment point, coolent lines run on exterior of front. The biggest issue was for it did not fit OUR needs it was not available as a kit.

RF40 - This is what we bought. The main reason was the Delux Kit was complete - like the models you built when younger - add glue and paint. As with anything you compromise - while the basic comonents and engineeering are first rate there are things that I think others do difernetly that I like, ie I like the latching method off the rear clip used by GTD/CAV; aluminium finish at the front base of the spider used by others. But these were minor and could be retro-fitted. The basic product had solid engineering and the interior was the most finished and very high quality. It was also available as a complete kit with a manual. All things concidered this was BEST for US.
Others have diferent needs (or wants) than we did so they make different decisions. Their decision is not wrong nor is our decision right for everyone.

As we work through the build I must admit that there are times I think I should have bought the turn-key minus, but then we work through the problem (a call is usually required)and forget about the turn-key minus. Robert took care of our two major concerns the panels (they did them) and fitting the body - he came up with a great solution. Gordon, Robert and memebers of this forum have been a great help, especially Hershal. But the nice thing is that almost everyone, no matter which manufacturer or which kit someone is building, appears ready to help any of us persue the dream of the GT40.

Sorry to be so long.

 

Great post. I like that you outlined the differences that you see in the various replicas. I've often wondered what some of the differences might be. Good luck on your build. I've seen pictures of Hershals car. Cant wait to see yours. I'm looking forward to the GT40 gathering in the future. Hopefully I can make it to the event proposed for this summer.

 

Yes Jay very good post. It gives a new buyer somethings to think about. 2 Questions: If you did NOT want a kit but a turn key minus what would have been your choice? 2 since I'm not mechanically inclined would you please explain in more detail this rear clip issue and cooling lines outside the car. Pics would help.
THX

 

Jay,
Your story sounds identical to mine except Hershal and I did the paneling.
Just like anything else the RF isn't perfect but it IS the PERFECT car for me. As I've said many times over without Hershal I'd still be scatching my head but Robert/Gordon are always very helpful and just a phone call away.
John
Great post and

 

[Knighton]

What were the major difference between the ERA and the RF?

I am not mechanically inclined and am looking at a complete turn key. I have been researching it for some time now and see that a turn key RF-40 will come in around $85K or less, where as an ERA 40 will come in around $110K or more.

Is the $25k difference worth the extra expense, in your opinion?

Thanks...

 

[Mike Dozier]

I've seen both cars up close.
I consider the RF the finest space frame
GT40 available, and the ERA the finest mono
replica available (H&M is not a replica).

Assuming you buy turnkey, I'd expect great
fit/finish/performance from both.
Biggest difference is the chassis.
How much extra are you willing to pay for
a more original chassis? That varies a lot from person to person. To some it's
worth $ 25k. To others...no.

MikeD

 

[Gary Gibbs]

If you are going the turnkey/turnkey minus route I also suggest you take a good look at the CAV. Check my site or www.cavgt.com

Dealers will do final motor install, etc. at a reasonable rate.

[ April 17, 2003: Message edited by: Gary Gibbs ]

 

[Knighton]

Mike and Gary,

Thanks for the reply. Any idea on the build times for a complete turn key for RF and CAV?

Gary,

That is somewhat of a monster engine (gulp!). Is the vehicle to be used at the dragstrip, or having that much power was done solely for the fun of it?

And,

What width of rubber are you running?

What is the maximum width possible?

[ April 17, 2003: Message edited by: Knighton ]

 

[Gary Gibbs]

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>Originally posted by Knighton:
Mike and Gary,

Thanks for the reply. Any idea on the build times for a complete turn key for RF and CAV?
<HR></BLOCKQUOTE>
Assuming the transaxles are available

the completion time should be arround 3 months (2 months for the turnkey minus and 1 month for the engine install).

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>
What width of rubber are you running?

What is the maximum width possible?

<HR></BLOCKQUOTE>
My car is setup with 245/17 front and 335/17 rear with the "gulf flared" rear fender option. This is effectively the maximum as there are really no other wider width tires available with 17" or smaller rims. You can run up to 315/17 with standard rear flares.

 

[Gordon Levy]

A Rf turnkey from us take approx 6 months to build. We do assemble every piece to meet your specs. With the variaty of options we have available it is a car specifically built for you.
A GT-40 is not one I would concider a drag car in any form. What do you mean by Monster engine?

 

[Knighton]

600+ hp is what I consider a monster engine, especially mated to a 2400lbs car intended for street use.

What do you consider a monster engine or one that is over the top? (not that I have anything against over the top...)

 

[Gordon Levy]

There are 2 types of monster engines. Drag race and road race. A drag race engine has a lot of hp and a lot of torque and won't live in a road race situation. The other type is a road race engine that has a lot of hp, not a lot of torque and is very smooth through the power band. They also are designed to rev very high for longer periods of time.
The drag race engine is not ideal for a GT-40. Being a mid engine car, it designed to be a finess car. Torque is not your friend. It makes the car harder to drive and control. The other concideration is with a mid engined car you are looking at a gear box that the costs start at around $10,000 and go up.
The GT-40 was designed as a road race car and will not fair well on a drag strip. The fun in this car comes from, having a daily driver street car with A/C that pulls better than 1 G through a turn on street tires and accellerating to over 180mph, then braking and going through the next turn.
I would be happy to talk to you at length about this if you would like to call me at 480-446-8442.

 

[Knighton]

"Being a mid engine car, it designed to be a finess car. Torque is not your friend. It makes the car harder to drive and control."

Forgive my mechancial inaptitude...

What are the difficulties or limitations associated with torque in the mid-engined car such as the GT40?

How is it different with a front engined car?

Does this affect turn in or corner exit, due to the inertia? And if it does, would one turn direction be enhanced by this inertia and the other direction inhibited, depending on the direction of the crank?

The Honda 500 cc GP bikes Mick Doohan rode in the 90s were very poor turning in and didn't handle as well as the Yamahas or Suzukis, but made up for it in the straights with the HP.

I am glad to hear RF offers ABS and Traction Control. How about xenon headlights?

 

[Mark Worthington]

I think I can safely speak for Gordon when he said, "torque is not your friend," what he meant was that:

a) Horsepower is a function of torque times rpm, and you can make the same horsepower at higher rpm with less torque than a "torquey" engine can make at lower rpm.

b) If you look at most mid-engine supercars, they make their horsepower at high rpm and are not brute-force torque monsters. Examples include Ferraris, Lambos, Maseratis.

c) Power is more difficult to modulate with a torquey engine, and given the mid-engine car's low polar moment of inertia, a torquey engine might make it easier for you to find yourself facing the wrong way without judicious use of the go-fast pedal on corner exit.

d) Torque, not horsepower, kills gearboxes, differentials, clutches and half shafts. More specifically, it's really dependant on torque multiplication (i.e., gearing), available traction, and vehicle weight. As Gordon noted, high-torque-rated GT40 gearboxes can be expensive.

All things being equal, you'd rather have a 400 hp engine that makes 300 ft-lb of torque than a 400 hp engine that makes 500 ft-lb of torque, because you can modulate the power better and put less stress on your drivetrain.

Of course, all things are not equal, especially the cost it takes to build a high-rev versus a low-rev engine.

 

[Knighton]

Mark,

Thank you for the explanation. Torque, I find, to be an interesting topic. The specs I am leaning towards concerning a powerplant is a Windsor 351 and 450 bhp. Not sure about the torque rating for this engine and hp figure. I would like to have a powerplant with decent low-end grunt as all my vehicles have lacked the low end punch (Daytona, Rx-7, CBR-600, GSXR-750, Intrepid R/T). Would like to just hit the gas an go for street use versus having to wait for the engine to spin up to make its power. Gearing will also have an effect.

Having to rev a 302 to get er' going does not appeal to me although the exhaust note would most likely be very sweet indeed.

What is your choice of engine, hp, and torque ratings - and why did you choose these your setup?

 

[Gordon Levy]

Mark's explination id quite good. Let's put it into perspective as far as power to weight.
RF GT-40 w/AC 302 powered 2250lbs
400hp/345lbft of torque
ZO6 425 hp 3600lbs
Suzuki GSXR1100 600lbs
150hp 100lbft of torque
RF= 5.5lbs per hp
ZO6 8.47 lbs per hp
GSXR 4lbs per hp

By the numbers the RF isn't as quick as the bike but will walk the ZO6.

Hershal's 400 hp RF will do 0-60 in 4 seconds, have a 12 second 1/4 mile driving it nicely and do 185mph. He also got 19 miles a gallon on his trip to LA.

You really don't need to have 600hp to have a supercar. when you get into cars with that level of hp, professional driving instruction or race experience is pretty much a necessity.

 

[Knighton]

At what rpm is Hershal's RF making the 400hp? Is this bhp? At what rpm is it making the 345 lb/ft of torque? Any idea what the gear ratios are and what speed they top out at? (perhaps I should ask Hershal!)

The Z06 weighs that much? What a shame. Geez, I was under the impression it was closer to 3000lbs, closer to the 996.

 

[Gordon Levy]

Actually I build hersh's engine. It is 400hp at 6400 revs and 345lbft of torque at 5250. Both the hp and torque curves are very smooth. These numbers are at the flywheel.
If you go through some past posts you will find several that were about Bob Bondurant driving Hersh's car at his track. The car was quickers than any of the school cars and quicker than a F40LM.
Be careful what you wish for, you want a car you can enjoy, not one that scares the hell out of you every time you get into it.

 

[Frank Catt]

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>Be careful what you wish for,you want a car you can enjoy, not one that scares the hell out of you every time you get into it! <HR></BLOCKQUOTE>Well said Gordon, that is the best advice we can give to any potential GT40 Driver/Dreamer

 

[Ron Earp]

Knighton, any 302 is going to have a LOT more grunt than the vechicles you mentioned, especially in a 2300lb car. And, built correctly these motors are a lot of fun to rev which is what everyone is indicating. I've driven Hershal's car, it is a hoot, has more than enough power, and it is only a little 306....

Ron