SLC Driving Impressions

This weekend I had the opportunity to drive Allan's SLC (thanks Allan). For those that aren’t familiar with his build, here are the high level details:

LS-376 crate engine and controller
Ricardo Transaxle with Stillen/AP racing clutch
Custom Long tube headers (stepped 1.75" to 1.875")
3" high flow cats and mufflers
Non run flat tires, but I can't remember the brand and model. I want to say Nittos. Maybe he will chime in.

Link to his build thread here: http://www.gt40s.com/forum/slc-clubhouse/33536-sl-c-50-allans-build.html

Otherwise it's a fundamentally "stock" SLC build. Same Brembo brakes, stock pads, and QA1 shocks set in the middle for rebound and compression per the build manual.

Street driving impressions:

1) Handling/Feel: Incredibly balanced. Absolutely glued to the road. It drove like an electic "slot car" for those who remember those. It goes exactly where you point it no matter the speed. No fuss, just the most confident stable feedback I have ever felt.

2) Transaxle: The Ricardo is THE transaxle for these cars in my opinion. At least for street driven cars. The gearing is perfect. It felt like driving my C6 gear ratio wise. The Stillen clutch was excellent and super easy to drive smoothly while holding all of the power. The Ricardo shifts like butter. Perfection.

3) Straight line traction, braking and acceleration: I punched it from a super slow roll on the street and the car squatted and dead hooked. Not a peep from the tires, no wiggle in the chassis. Braking was non eventful and felt very good. I have to get used to manual brakes again. It’s been a long time since I’ve driven a car with manual brakes.

4) Bumps/noises: Very well composed. No noises, clunks, or anything to apologize for. Of course I knew I was driving a sports car and not a Cadillac. It handled the bumps a lot like my Corvette with coilovers. The solid engine mount is a non issue. I was very worried about the solid engine mount and having it transmit vibration to the interior. Non issue. I was also worried about the the lacking of bushings in the car and the race car suspension. Non issue. In fact I suspect that’s one of the reasons the car tracks so well.

On another note: The amount of attention this car receives is ridiculous. Don’t be in a hurry when you stop anywhere with this car.

I bought the right car. :thumbsup:
 
The solid engine mount is a non issue. I was very worried about the solid engine mount and having it transmit vibration to the interior. Non issue.

I'm particularly interested in this part. Can you expand on your description for this part? Like. . felt none, barely noticeable, you gotta be looking for, etc. We too are "concerned" but aren't sure if the Pfadt mounts would make any difference.
 
As one of the people that bought the car without ever riding in one - this impression answers a lot of the concers I had on the drivability on the street. Mainly the rose jointed suspension and the solid engine mounts.

Thanks Allan for sharing your 'stock' car with the rest of us - makes the owner of chassis 001 even more satisfied with his purchase.
 
That just means your cam isn't big enough :)

Agreed! With the G8 I feel every bit of the cam sitting at the stop lights and it's on factory engine mounts. Love every bit of it!!

Thanks for the review!! I spoke with the guy from griffin gearboxes (completely forgot his name) for about 20-30 mins last night and I'm feeling very comfortable about using one of his units in my car. They are reasonably priced as well and easy to work on from the way he was talking. 11k for the street box and about 15k for the race box. I'm really lookIng forward to seeing how the 01 car handles the box when Fran puts it in!
 
I'm particularly interested in this part. Can you expand on your description for this part? Like. . felt none, barely noticeable, you gotta be looking for, etc. We too are "concerned" but aren't sure if the Pfadt mounts would make any difference.

I'd be more concern with long term metal fatigue around the mounting area. Any opinions?
 
I'm particularly interested in this part. Can you expand on your description for this part? Like. . felt none, barely noticeable, you gotta be looking for, etc. We too are "concerned" but aren't sure if the Pfadt mounts would make any difference.

Non issue: If I didn't know it had solid engine mounts, I would have guessed it was running factory GM mounts. I don't pretend to know the physics why and what I will write to respond to Alex below will tell more of what I mean by that, but it just wasn't an issue at all.

I have been in/driven in a GTM (Allan's) with the identical crate engine ls376 using the factory GM LS engine mounts (much softer than pfadts). Neither the SLC or GTM transmitted any abnormal/unexpected engine vibration to the cabin and felt very similar or even the same as far as transmitting engine vibration to the cabin.

That just means your cam isn't big enough :)

You are mistaking "lope" rocking the car for vibrations transmitted into the cabin. They are not the same thing.

I just sold my 2008, but I still have my 05 c6. My 2008 was left completely stock, but in the past 5 years I have had 5 different engine combinations in my 05.

1) Stock
2) Heads/cam (big cam)
3) 402 Stroker (big cam)
4) Cheater Cam w/springs, otherwise stock longblock
5) Big cube ITB LS

Yes, engines 2 and 3 rocked my car back and forth and made the driver and passengers look like bobble heads, but it didn't really transmit the type of vibration I am referring to.

The vibration I am referring to happened when I ran pfadt engine and tranny mounts in my c6. Even with a STOCK ls2, there was a driveline vibration that was not acceptable to me. I called pfadt and they recommended I removed the tranny mount and leave the engine mount first before dumping both of their kits. I did that and the driveline vibration basically was non existent. I ended up buying another set of pfadt engine mounts for my other c6, but sold the tranny mount.

That is the driveline vibration I was worried about being a problem with the SLC. It wasn't an issue at all though. I am sure with a monster cammed engine it will rock the car back and forth, but that will happen if you put a monster cam in a Cadillac CTSV as well. Any car for that matter.

BTW, the LS376 has a lot of lope for a GM crate engine. Not as much as your 502 will someday though.
 
I seriously hope you are wrong about that. That is MUCH more than first reported. For which street box were you quoted this price?

I have slightly higher power goals than most so that's the reason for the cost. This street box price is for the top of the line 6 speed that will hold 800-1000 fairly well. Give them a call. The owner is the guy I talked to and he is a very honest and straightforward guy. I can't wait to do business with him in the near future!
 
I have slightly higher power goals than most so that's the reason for the cost. This street box price is for the top of the line 6 speed that will hold 800-1000 fairly well. Give them a call. The owner is the guy I talked to and he is a very honest and straightforward guy. I can't wait to do business with him in the near future!

Our needs are much more modest than yours, which would explain the difference in cost expectation.
 
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