Aren't you being just a little touchy? Haven't you ever seen something posted on the internet in good faith that turned out to not be true? If you are the veritable fountain of truth, then I apologize for even suggesting that you could possibly post something that is incorrect and I will never question any of your posts again.

Satisfied?

 

I believe the two sources that you refer to are as believable as we get on this forum. Your point is well taken.

 

If you want to take the nitpicking one step further it should be noted that the GM Powertrain facility that took over race engine building from Katech in 2010 is located next door to the Performance Build Center in the same industrial park in Wixom. The race engine building is done by GM Powertrain, not the PBC. Katech built the race engines until 2010, Pratt & Miller always built the race cars.

 

All true and was verified and updated in posts #5 and 8. I guess we are done here.

 

We had a flawless record with the engines. It wasn't a money issue as we are probably cheaper. GM built the all new Wixom facility so they could do those types of programs in-house.

 

In reference to the bolded, I absolutely agree...your apology above is a perfect example.

 

I don't think anybody has been nitpicking but nobody in this thread said the PBC was building the race engines. The link I posted and bearmans both stated the race engines were built AT the PBC in Wixom with bearmans confirming they were built in the same building (just a different area), not next door to the PBC. And just to be clear, the race engines are of course built in different buildings now that the PBC has moved to Bowling Green.

It's crazy the same thing has to be stated three times now before it sinks in...

 

Well, there are several explanations that the C7.R engine is not an LT1 engine with bore and stroke sized to make 5.5L because they already have some other engine with bore and stroke sized to make 5.5L.


C7.R engine
4.09 bore
3.185 stroke

LS7 engine
4.125 bore
4.00 stroke

LS3 engine
4.065 bore
3.622 stroke

LT1 engine
4.06 bore
3.62 stroke

Then there's a link in this subject that says that the LS5.5R engine is based on the LS7 engine
.

 

They were allowed to run the LS5.5R from the 2013 C6.R for the 2014 season. It's a sleeved LS7.

 

There's an idea of swapping an LS7 crate engine into a C7 for the purpose of making a dedicated track car. The LS7 crate engine has its own engine controller and therefor all the C7 OEM electronics and street equipment can be pulled off.

It is a big job but weight reduction is the benefit. Also, the anti-lock brakes would be replaced with a race-part master cylinder with bias bar adjustment. The electronic limited-slip would be replaced with an adjustable race-part mechanical limited-slip. And so on. The rev-match manual transmission could probably just be unplugged or else replaced.

The LS7 crate engine has 505 HP. It has very good internals but does have cast pistons. GM also has a Gen 5 LT1 crate engine not yet released. So then the engine controller for the LT1 crate engine might be used on the C7 for the purpose of removing all the C7 OEM electronics and street equipment
.

 

I believe the Gen V engines(LT1) have a different motor mount location
from the Gen IV engines(LS7,etc), thus they are not a direct drop in into the C7 chassis.

If you are going to that much trouble to fit a LS7 into the C7, why not sleeve the LT1 that came with the car to a 4.125" bore and install a 4" crank with new rods and forged pistons, and ported heads, etc. It would give you the 427 cu in displacement yet have stronger components.

http://forums.corvetteforum.com/c7-t...-corvette.html

 

The LS7 crate engine has a forged steel crankshaft, forged titanium connecting rods, and titanium intake valves. It has a dry sump system. Also, it has its own electronics such that the C7 OEM electronics can be pulled off the car. That allows a C7 track car build without any street equipment.

http://www.jegs.com/p/Chevrolet-Perf...03674/10002/-1

But when the LT1 crate engine comes out then a simple engine controller will be available for the LT1. But yeah, when the LT1 engine controller is available, I would think about an LT1 instead of adding motor mount brackets to the C7.

And most of the GMPP crate engines are not just replacement engines but also engines for street-rod builds but that makes the street-rod electronics available for those who already have the engine:

http://gmauthority.com/blog/2013/11/...ngine-concept/


Well, don't misunderstand a race car build. All the OEM wiring, fuse boxes, and junction boxes are pulled off the car. Then the car is just re-wired as a race car build. The seat motors come out, the airbags come out, the dash comes out, and all street equipment is pulled off the car. The anti-lock brake parts are pulled off the car and a master cylinder with bias bar adjustment is used. The electronic limited-slip is replaced with an adjustable mechanical limited slip. The simple engine controller electronics of the crate engines allows the street equipment to be pulled off and of course one engine that is available is the LS7. Finally, a race car build pulls 500 to 800 pounds weight off the car and then adds the weight of a roll cage back
.

 

I doubt it, many of the questions asked in her were answered in here back at the beginning of the year. Aero packages, clear taillights etc etc.

 

At the risk of offending somebody again, is it a known fact that the C7R does not have an electronically controlled Diff? I would think that this would be a performance enhancing feature that would be desirable to keep if the rules allowed it. F1 has been using these for years. From what I've been reading, the e-diff is a big part of the
package that improves the C7's handling.

 

If it's any help, the part numbers for the LT1 crate engine are #12657236 & #126572248 and you can pick one up for $7,294.44. And the LT1 is available from the factory in a C7 with a dry sump and in a crate engine. But my point was that if you purchase a C7 to modify into a race car, it will have a LT1 engine in it, so why not build the LT1 that came with the car into a 427 cu in engine, if that displacement is your goal. A LT1 fitted with Darton sleeves will be stronger block than a stock LS7 block with stock sleeves. Adding a Callies forged 4" crank and Ultra rods along with ported heads that will flow as well as the LS7's(and adding larger Ti intakes valves at the same time) will give you a much stronger engine(to withstand the abuse from racing) then sticking a stock LS7 with cast pistons and questionable quality heads into a C7.

I don't misunderstand a race car build and the reduction of weight of the race car, but that has nothing to do with the decision of which engine you are going to use; a 427 cu in LS7 or a 427 cu in LT1.

 

Most everything on a race car is individually adjustable. The OEM C7 on the other hand has selectable performance levels. This is just two different worlds. Also, the electronic limited-slip on the OEM car is tied into the performance-traction-system. That system heats up the rear brakes to control wheelspin. A race car wouldn't use up the brakes like that.

A race car could have an electronic limited-slip but the purpose would be easier adjustment and there would need to be a computer to run it. The OEM electronics are too elaborate and tied into too much street equipment to use on a race car.

Similarly, race cars usually don't have electronics running an anti-lock braking system. More often they have a master cylinder with a bias bar adjustment.

(Certainly, Formula 1 has everything but they are not using OEM parts.)

Finally, take a look at the fuel-injected GMPP crate engines and several of them include an engine controller electronics that only controls fuel injection and ignition. There are no electronics for limited-slip and anti-lock brakes. (I suppose that the crate engine electronics are still expecting a cat between oxygen sensors.)

The race car might have OEM electronics with complete and total re-programming but that would be unusual.


Here are two links to the Viper Competition Coupe:

http://www.caranddriver.com/reviews/...specialty-file

http://www.allpar.com/cars/viper/competition-coupe.html

That's 3190 pounds weight including roll cage. That's fairly heavy but probably due to the SCCA World Challenge rules. And it's just some photos of a production car built into a race car.


I'll go to the Corvette Racing website and look for interior photos and under-the-hood photos
.

 

Yeah, I just personally need the crate-engine street-rod electronics to make the C7 into a race car or into a dedicated track car.

I'm replacing electronic limited-slip, taking off anti-lock brakes, taking off AFM, pulling out the entire dash, taking out airbags, and so on.

Don't replace engine or build engine either one. Just replace the engine electronics and then the shop-built price of the track car drops by twenty-thousand
.

 

OK, so we don't really know if the e-diff is part of the C7R package or not. The Pirelli World Challenge cars use quite a bit of the factory electronics including ABS if what I have been hearing is correct. I have tried driving my C4 without ABS and found that it is near impossible to avoid brake lock-up, but I don't think the C7R has much if anything left of the factory braking system.

 

Here is a quick link I found about a brake system for World Challenge:

http://hpd.honda.com/%5Ccontent%5Cme...ura_TLX_GT.pdf

Also, check out the electronics for the car !


Here is a link about the C6.R as compared to an OEM car:

http://gmauthority.com/blog/gm/chevr...rvette-racing/

The brakes are different and the transaxle is different. Electronics would be interesting.


See, the OEM anti-lock brake system is not adjustable. A racing master cylinder is adjustable with a bias bar.

Also, the anti-lock brake system is included in the stability control systems and so there's a lot of electronics involved. Race cars don't usually have stability control systems unless it's some high-end system for pulling 3 to 5 G's
.

 

Thanks, that's interesting. Maybe I had the wrong series, or maybe Some teams are trying to get by with less equipment, but you can see from this list that there is virtually nothing on the car which is OEM. When you go to ALMS GTE, that list probably goes to zero. Maybe a roof panel.

I have seen a brake bias adjuster added to a factory ABS system, though, and it seemed to work fine.