SL-C vs FFR GTM Supercar

Brad R.

New Member
#1
I have heard many good things about these kits. I know RCR sells rolling chasis and FFR uses a a C5 as a donor car but in terms of performane and bang for your buck which one is better and why? They both look sick, that's a given, haha :happy:
 

Doc Kaler

Active Member
#2
Hi,

As you can glean from my Avatar,etc., I have an SL-C in progress currently. I would wager that the final costs will come out about the same for the SL-C, GTM or Ultima for that matter. So, your decision will come down to both styling and technology.

What made me decide on the SL-C was the monocoque aluminum chassis rather than tubular, bespoke suspension parts rather than decade-old donor parts designed for a front engine vehicle, some flexibility in engine and transaxle choice, overall design similar to Daytona Protoypes and styling, fit and finish of the fiberglass body as it comes from Fran. The PDG guys at FFR.com have put a lot of work into their car and comparing it with the standard GTM.....well no comparison. Jay Salmon has test driven the SL-c "mule" I believe at VIR and did a pretty good write-up on this site.

I am confident that the SL-C track performance should equal or better the PDG performance although I am, as others, not at a completed state. Bear in mind that the SL-C is a newer design, fewer out there yet!
 

Alex

Active Member
#3
I agree with Doc - GTM, SLC, Ultima, final build costs will be within 5% of eachother more-than-likely in a quality build.

However, imho, SLC has a better foundation to work with - better frame, better body, better parts, better everything, and more modern. Plus there's just some scary stuff with the GTM. Like take the fuel tank, punch holes in it, slather in aircraft sealing epoxy and hope it doesn't leak gas.
 

Brad R.

New Member
#4
Hi,

As you can glean from my Avatar,etc., I have an SL-C in progress currently. I would wager that the final costs will come out about the same for the SL-C, GTM or Ultima for that matter. So, your decision will come down to both styling and technology.

What made me decide on the SL-C was the monocoque aluminum chassis rather than tubular, bespoke suspension parts rather than decade-old donor parts designed for a front engine vehicle, some flexibility in engine and transaxle choice, overall design similar to Daytona Protoypes and styling, fit and finish of the fiberglass body as it comes from Fran. The PDG guys at FFR.com have put a lot of work into their car and comparing it with the standard GTM.....well no comparison. Jay Salmon has test driven the SL-c "mule" I believe at VIR and did a pretty good write-up on this site.

I am confident that the SL-C track performance should equal or better the PDG performance although I am, as others, not at a completed state. Bear in mind that the SL-C is a newer design, fewer out there yet!
How much do you estimate the final cost for your LS7 SL-C to be?
In terms of styling, I agree, the SL-C looks like a bona fide race car that's way above any production car in status.
 

Brad R.

New Member
#5
I agree with Doc - GTM, SLC, Ultima, final build costs will be within 5% of eachother more-than-likely in a quality build.

However, imho, SLC has a better foundation to work with - better frame, better body, better parts, better everything, and more modern. Plus there's just some scary stuff with the GTM. Like take the fuel tank, punch holes in it, slather in aircraft sealing epoxy and hope it doesn't leak gas.

That's what I was thinking. My friend saw an Ultima on Top Gear and jizzed his pants taking about how it's the fastest car in the world, but these other kits have just as much an opportunity to reach that performance. I have encountered many GTM people having trouble with their builds. Is the SL-C as difficult to put together? Also, does RCR build SL-C turnkeys?
 

Jack

Bronze Supporter
#6
My SL-C was chosen after looking at a few, GTM builds in progress, and driving their demo car at Road Atlanta a couple years ago. Man, am I glad that I made the right decision. As mentioned, the SL-C costs for a decent completed car would be similar to either the GTM or the Ultima, with the GTM a bit cheaper and twice the work!

The SL-C build is pretty straight forward, body is aligned to the chassis for you, the fiberglass fits are very good, and the chassis is like jewelery! Talk to RCR about a turn-key but I would recommend a visit first. IMO the best engine/gearbox combo for the SL-C is the LS376/480 with the ricardo transaxle. LOTS of bang for the buck!
 
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Alex

Active Member
#7
How much do you estimate the final cost for your LS7 SL-C to be?
In terms of styling, I agree, the SL-C looks like a bona fide race car that's way above any production car in status.
I have receipts for around 100k so far for mine.

That's what I was thinking. My friend saw an Ultima on Top Gear and jizzed his pants taking about how it's the fastest car in the world, but these other kits have just as much an opportunity to reach that performance. I have encountered many GTM people having trouble with their builds. Is the SL-C as difficult to put together? Also, does RCR build SL-C turnkeys?
Difficult is a relative term. Right now I've got about 800hrs of work (soft and hard) into it, and barely scratching the surface in terms of being finished, mainly because I think think double think about everything. Are you going to be able to pput it together in 50hrs and be rolling down the street - no. Will you be able to finish it without fancy machiney and expensive help - absolutely.

The way I look at it is you need 3 things - time, money, and skill. No time, then you need money and somebody elses skill. Be like me an hav eno skill - you need a lot of time and money to make up for it.

With the GTM, my understanding is one of the primary headaches is the bodywork - hundreds of hours because of poor quality. SLC has excellent bodywork with minimal effort needed to get to paint ready (and you can be like me and just polish the gelcoat and leave as is for a while until you're ready....polishes out just like single stage paint)
 

Jack

Bronze Supporter
#8
Ryeno,
A well done SL-C will be a bit less than 80K if you do the work and paint yourself, or as Alex said, polish up the bodywork. Alex did a beautiful job on his gelcoat.

I got a deal on a LS1 which I modded and a 930LSD gearbox. That is why my total cost is as low as it is. To date, just over 60K and did all the work myself, sans a bit of aluminum welding. Ready to do final assembly and paint at this point in the build. I did spend considerable time deviating from the original specifications though. About 150 solid hours total. Estimate that the car could be done (by a mechanically knowledgable person) in 200-300 hours. That is, following original spec (without special paint & upholstery) and without many options. IMHO of course..
 
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#9
for sure, bodywork is an issue on the GTMs. Everybody who has built one has to monkey with the wheels wells to get the wheels centered in the opening. Don't know about you, but I find that fiberglass work is really messy and not tremendously rewarding.

I'd rather do mechanical work any day.
 

Alex

Active Member
#10
for sure, bodywork is an issue on the GTMs. Everybody who has built one has to monkey with the wheels wells to get the wheels centered in the opening. Don't know about you, but I find that fiberglass work is really messy and not tremendously rewarding.

I'd rather do mechanical work any day.
I'd rather just sit there and polish the gelcoat all day. Polishing is fun :drunk:
 

Doc Kaler

Active Member
#11
Ryeno,

My engine build is for normally-aspirated track use. So, although it started with a "cheap" LS7 new-in-crate for $10,000.....it now has upgraded internals, head-work, Ported FAST 102mm intake, Williams DBW 105mm TB, ARE dry sump pan, 3 gal Peterson oil tank, oil cooler, Aviad scavenger pump, custom cam, upgraded internal oil pump, Jesel roller rockers and roller lifters. I have the receipts but I'm afraid to add them up! I started with a G50.50 but found a Ricardo for $5200 and shipped the G50.50 to Australia. In terms of "bang-for-buck", go with Jack's recommendation.
 

Dave

New Member
#12
I almost bought a GTM myself. I went and saw a 90% completed build and was impressed with what I saw. The car was beautiful and the builder did a fantastic job with many custom details. He did however disclose many issues that he had with the build, many of them mentioned in this thread and along with others, well documented over on the FFR forum. I'd own the GTM had it not been for getting ripped off with my engagement ring and the ensuing financial battle I had that delayed my decision to buy a car. In that time, more details of the SL-C were coming out and I liked what I saw better, especially after I saw one in person before I decided to buy.

I also considered the Ultima and we all know they are bad-ass, no argument about it. The car is a proven, well developed platform but in the end, is 15+ years old, and the bodywork, especially the front end, show its age. In the end, I think the Ultima would have been the most expensive build of the three (all else equal). I also was more keen to support a US based company and not have to worry about international this and that.

I think your choice should depend on what you are looking for. A nice street car that is fun on the track or a track car that is fun on the street. Keep in mind that although the SL-C suspension is specifically desigend for the car and beautifully made, it uses spherical bearings in place of rubber/eurathane bushings such as the Corvette donor suspension used for the GTM. Whereas the ride quality (this being relative of course) will suffer in the SL-C vs. the GTM, the SL-C's suspension is far more adjustable and the end result should enable a skilled driver to drive circles around the GTM on the track.

The design of the chassis in the GTM, particularly of the halo bars close proximity to the head, and lack of side impact/intrusion protection were of great concern to me. You sit at the outer edge of the GTM due to the massive central tunnel. With the SL-C, you sit as far inboard as possible while still maintaining a passenger seat. That combined with the door bars I and a few others opted for, I will feel real safe at speed in the car. There is also plenty of headroom between you and the rollover protection and there is even a sunken floorpan option for the giraffes out there.

The entrance fee of the GTM is certainly cheaper than any other comparable options, but after you factor in donor costs and the additional costs to complete the bodywork, that becomes a moot point. Don't forget about your time either.

Fran's (factory) support has been stellar too.
 
#13
Ryeno,

My engine build is for normally-aspirated track use. So, although it started with a "cheap" LS7 new-in-crate for $10,000.....it now has upgraded internals, head-work, Ported FAST 102mm intake, Williams DBW 105mm TB, ARE dry sump pan, 3 gal Peterson oil tank, oil cooler, Aviad scavenger pump, custom cam, upgraded internal oil pump, Jesel roller rockers and roller lifters. I have the receipts but I'm afraid to add them up! I started with a G50.50 but found a Ricardo for $5200 and shipped the G50.50 to Australia. In terms of "bang-for-buck", go with Jack's recommendation.
Wow, they just keep addaing up! I've been overhearing a lot if talk about the Ricardo 6-speed transaxles. How do they stack up against the Porsche ones (G50, GT3, etc)?
 
#14
I almost bought a GTM myself. I went and saw a 90% completed build and was impressed with what I saw. The car was beautiful and the builder did a fantastic job with many custom details. He did however disclose many issues that he had with the build, many of them mentioned in this thread and along with others, well documented over on the FFR forum. I'd own the GTM had it not been for getting ripped off with my engagement ring and the ensuing financial battle I had that delayed my decision to buy a car. In that time, more details of the SL-C were coming out and I liked what I saw better, especially after I saw one in person before I decided to buy.

I also considered the Ultima and we all know they are bad-ass, no argument about it. The car is a proven, well developed platform but in the end, is 15+ years old, and the bodywork, especially the front end, show its age. In the end, I think the Ultima would have been the most expensive build of the three (all else equal). I also was more keen to support a US based company and not have to worry about international this and that.

I think your choice should depend on what you are looking for. A nice street car that is fun on the track or a track car that is fun on the street. Keep in mind that although the SL-C suspension is specifically desigend for the car and beautifully made, it uses spherical bearings in place of rubber/eurathane bushings such as the Corvette donor suspension used for the GTM. Whereas the ride quality (this being relative of course) will suffer in the SL-C vs. the GTM, the SL-C's suspension is far more adjustable and the end result should enable a skilled driver to drive circles around the GTM on the track.

The design of the chassis in the GTM, particularly of the halo bars close proximity to the head, and lack of side impact/intrusion protection were of great concern to me. You sit at the outer edge of the GTM due to the massive central tunnel. With the SL-C, you sit as far inboard as possible while still maintaining a passenger seat. That combined with the door bars I and a few others opted for, I will feel real safe at speed in the car. There is also plenty of headroom between you and the rollover protection and there is even a sunken floorpan option for the giraffes out there.

The entrance fee of the GTM is certainly cheaper than any other comparable options, but after you factor in donor costs and the additional costs to complete the bodywork, that becomes a moot point. Don't forget about your time either.

Fran's (factory) support has been stellar too.
Thank you for being so comprehensive! This was exactly the kind of evidence I was looking for.
 

Jack

Bronze Supporter
#15
Ryeno,

The Ricrdo gearbox will handle almost any horsepower and torque that you can throw at it. Favorable ratio's, great prices right now (better than most other P choices).
 
#16
Ryeno,

The Ricrdo gearbox will handle almost any horsepower and torque that you can throw at it. Favorable ratio's, great prices right now (better than most other P choices).
Damn, now that sounds just right for my SL-C build!
How much do they cost and who sells them?
 
#17
The Ricardo box is the ZF of the early 21st Century. Remember how cheap & plentiful ZF's were during the 70s when Ford was importing the Pantera? The supply is finite, and eventually will dry up. I almost feel bad for the GT guys 25 years in the future, when they have to round up replicas in order to find cases, parts & whole units to restore/repair their cars....
 

Doc Kaler

Active Member
#18
Ryeno,

Occasionally, these crop up on eBay. Adrian Turner of DAB Solutions in the UK sells them at $8400 including shipping to the USA. Fran Hall has a few I believe.
 
#19
I have built a GTM. About 4000 hours in it over the last three years and it still lacks paint. I have looked at the SLCs closely and everything is far superior. The GTM bodies are very poor and require a tremendous amount of work. Everything on the car is asymetrical. Most of the body parts have to be modified to fit. The right side of the body is completely different dimensionally from the left. The chassis has more flex than it should. Jack it up and the doors don't want to open. Quality control is poor and several people have had to remove pick up poits on the chassis and reweld them. Detail design is also poor. There are a lot of things on the car that they could have done differently that would result in a better car.

Ergonomics was not considered in the design. There is no way to enter or exit the car gracefully. Visibility is not good out the front as well as the back. It has a large windshield but the height is very low. There is no way to position the seat so you do not rest you head on the side of the halo bar unless you remove part of the tunnel. Head height is minimal for average people.

People like the design of the GTM body. The entrance price is lower than the SLC. The final price is in the same ballpark. If you throw in labor at minimum wage, the GTM is twice the price of a SLC for a lesser vehicle. My next car will be a SLC. AS far as I can tell; the detail design, the body, and the chassis are all far superior to the GTM. With a lot of work the GTM can be made into a good car but it takes a tremendous amout of work.

Just my two cents worth.
 
#20
As a proud owner of a FF Cobra, I may be biased, but the bias goes the wrong way. When the folks that did the body work and some final stuff on our Cobra built a really nice GTM and said it was a total nightmare... well I think that sums it up.

FF was started on the concept of building an inexpensive fun car. They were successful, and they continue to be successful in that area. You cannot build an inexpensive supercar. It's just not going to work. The GTM is not even marketed as a track car, but more as a Ferrari/Lambo fighter. I am sorry, but in this regard, you have to be kidding. And when you can buy a used Gallardo for LESS than it will take to build a GTM?

I have a good friend with a very nice Ultima, very very fast. He got to go over the SLC test mule with us and declared the car to be a huge advance over the Ultima.

Hoping to drive ours on track within the next few weeks.
 
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