whatcop?

I know I know its egregious to use a boosted motor on a road course.... But that didn't stop me. My last motor seems to have either seized a main bearing or an ARP rod bolt let go, and I will never truly know. That being said I use my car as an all around toy. The car will only hit the road course about 4-5 times a year and will most likely only be road atlanta. As far as cooling goes I've never really had an issue because I tended to all the little issues I noticed over time. As far as cooling goes I have hard wired the stock fan (which works phenomenally well), KP racing ice tank in the rear which holds ~8 gallons, stewart LPE intercooler pump, Vengeance Racing HX, straight pass HX (mounted right in front of the under car air dam), water wetter, wrapped exhaust to tail pipes (as to not transfer heat to radiator via transmission) and removed the stock hood window and replaced it with a vent from ACS. Also when I do go to the road course I will swap out the upper pulley from the current 2.2 (soon to be 2.175) to a 2.6 to tone the car down. Lastly she is flex fuel capable and so I run her on e85 99.9% of the time.


Comments and thoughts are always appreciated because I am forever learning about these cars and enjoy hearing other views.


https://www.corvetteforum.com/forums...ce-racing.html

BrianCunningham

That's a LOT of compression for a boosted engine

Charley Hoyt

I stopped reading when I got to "iron block". Looks like it will be a really fun car for the street, but doesn't seem to make much sense for a track car. Maybe I am just warped.... Ever sense I switched to a 1,300 lb race car with 1,700 lbs of downforce , and have experienced the value of low weight, I can't see adding weight... And definitely not to the front. But it is your money so build the car that best fits yout needs... Not mine . Enjoy the car

C5 Hardtop

Are you going to bring the car on a trailer? Looks like it would be fun. I think it will be skittish trying to lay down the power on track.
I'd have an eye on the knock retard. Like Brian said, that is a lot of compression for a boosted motor. 11:1 is high compression for a naturally aspirated motor What octane fuel do you use?

whatcop?

Hence the reason I went with stout parts including the iron block.

Honestly after doing my research the LS3 to LSX block is about 100lbs in weight increase. The LSA/9 to LSX block is probably closer to a 80lbs difference. The car is more of an all around car. The intention was for it to be semi decent at anything I use it for and not designed to excel in one area primarily. When I go to the road course I am just out there to have fun at HPDE events. Also there is quite a bit of ballast weight in the rear that offsets the block. I have a 8 gallon ice tank for the intercooler and have a ~70lb battery. The ZR1 has been a fat pig from day one so to lighten it up a bit I have recaro pole position seats, headers, and no mufflers. So in the end I am sure I am heavier than stock, but how much heaver I don't know since I haven't had a chance to get it on a scale yet. I'm typically not into big girls, but this is one I can get behind

The car is setup with a flex fuel system and so I run e85 99.9% of the time. Also I have meth added as a safety net. And when I do take it to the road course I will swap the 2.175" upper pulley to a larger 2.6" to tone things down. I am crazy, but even I know when to stop doing silly things lol

FASTFATBOY

whatcop?

Why do you feel that way?

FASTFATBOY

So your factory engineered boosted engine came unwound and you are going to reengineer it with even more stress and expect it to live?


Boosted engines don't live on track, that's just a known fact. The factory stock, untouched boosted engines last 1/2 as long as a normally aspirated one does when used on track.

Guys spend huge money to learn this lesson, even after it's been proven over and over and over. Even guys with modified normally aspirated engines end up going back to stock for longevity reasons in DE cars.

BrianCunningham

with e85 the compression makes more sense

You can make a boosted engine last
take a looks the the LeMans winners

whatcop?

That's a pretty silly argument. That's like saying a prostock motor can't exist because the engineers over at Toyota couldn't make a stock camry motor hold 4000hp.

I would get your point if I had taken an off the shelf ls9 and milled the heads to bump compression and then thrown gobs of boost at it and said alright this thing is going to log 100,000 miles on the track reliably. However I built a motor with overly strong components and plenty of octane fuel.

Agreed. On my old setup I was making 640/680 on 93 octane and on the road course I would see coolant Temps of 230-240 and an oil temp best of 280 in 100* weather during a 30 minute session. I've now added meth, e85, headers with full exhaust wrap, 8 gallon intercooler ice tank, and a secondary heat exchanger. I can still add an external oil cooler, hard wire my fan or upgrade to duals, upgrade radiator if needed.

Plus when I pulley down I will drop about 4lbs of boost. I believe people have really gotten caught up with old parts that were not capable of handling the stress of high compression and high boost. Look at the GTRs they are running around with insane levels of boost on a small volume motor which theoretically increases compression.

And to add fuel to the fire my previous coolant and oil Temps compete with NA cars while on the track. My C6Z would flash the A/C message (I did not have my A/C on) on hot days from how hot it was running at road Atlanta while the ZR1 never did.

FASTFATBOY

Annnnd look at their budget. After LeMans those engines are basically thrown in the garbage.

I have seen so many boosted cars go back on trailer blown up on the first day of a DE weekend it's almost comical. Only the untouched factory engineered cars last and then it's usually half as long as their normally aspirated counterpart.

Any car that had boost added by its owner fails even quicker.

Any guy in here will attest to this if they do regular track weekends.

FASTFATBOY

Op please give regular updates once it's put on track.

BTW, how long did the original engine last and what were it's mods?

You can make a boosted car live, if you drive it at 7/10's of it's capability.

whatcop?

I definitely will keep everyone updated.

I think that is a moot point, because my C6Z with only a cam, tune and intake dropped an exhaust valve with 13k on it while at sebring on my 3rd lap of my first day there while taking it easy on a damp track on slicks. We all know how many C6Zs have dropped exhaust valves so kudos to the engineers at GM on that one.

ZR1 history:

618 miles- Supercharger was defective and replaced by GM while car was bone stock

8000 miles- Rings were shot and I personally pulled it apart to rehone the motor and replace the rings (seems to be a common problem with them) Car made 640/680 and then went down to 620/640 due to the rings being torn up. Car was trailered to a lot of tracks so a very decent amount of those miles were track miles.

10,000 miles- Either an ARP rod bolt failed or crank bearing seized and tossed a rod out the block. Picked up off the track some interesting looking parts. A bearing that was bronzed from heat and stretched and an ARP rod bolt that was cleanly sheared in half with what appeared to be stretch around the head of the bolt.



Lastly, I completely agree with your point and you can achieve this with over engineering a build. My motor should handle over 2000whp and I will be switching pullies for the track and run E85. So if you think about it I am pushing a bit more than 25% of what the motor is truly capable of handling.

SouthernSon

When you find comfort in holding the throttle to the floor things begin to adversely happen quickly to the drivetrain. After a few thousand dollars here and a few thousand dollars there most of us begin to think it may have been just as much fun, if not more, had we just left it stock and concentrated on keeping it cooled, able to turn and able to stop. But, if you don't mind tearing down and rebuilding a few times, not to mention down time and money spent, then it may be a fun endeavor. One more thing I might add, you might consider a full cage and fire suppression system. When an engine lets loose all kinds of slippery, hot bad things happen not only to the vehicle with the blown engine but to those behind as well.

Ls240sx

You should just give up, your boosted engine will never last...

FASTFATBOY

You can't convince me, the results speak for themselves. You're trying to climb a mountain with grease on it as many have tried and failed.

By the time it's over, you'll realize how much more fun a stock C5Z would have been...not to mention the track time you could have bought with all that money you're flushing.

whatcop?

Cage is in the plans in the near future hopefully. Don't need to preach to me about what happens lol


Not trying to convince anyone of anything, I simply posted my build to share it with others in the community. My car, my money, and my headache.

FASTFATBOY

You'll need this lol.

AND0

if you keep the boost down to ~7 lbs that combo should live forever and stay cool.

Hi Volts Z06

Some people get their kicks driving a race car fast around a track.....

Some people get their kicks telling people how much HP they make.

The first kind contribute to this section of the forum.