NoOne

I've wanted to go back to FI but everyone tells me, and I concur, FI has no real place on a road course with an C5 due to cooling issues.

For the way the ZR-1 is being sold as a supercar with a SC...so how is it going to hold up to long sessions on a road course?

The Ford GT has a SC but the car was designed around the engine and there is a ton of room in the back of one of those for cooling.

The ZR-1 motor is being stuffed in a C5/C6 engine bay.

Bad news...it doesn't work and there are overheating problems.

Good news...it works and there will be some solutions for those looking for FI and HPDE's/road racing.

Or split the difference...its going to be a good road car as it sits, change one little thing and introduce all kinds of problems.

Won't be long till we find out.

AU N EGL

Heat is always an issue. Get rid of the heat and giddy up.

2000BSME

my personal opinion is that it will be a novelty car, much like lambos and such, and will rarely see much track time. I doubt it will be adopted by any racing teams because of the FI.

But I didn't stay at a Holiday Inn Express last night, or any time recently.

BrianCunningham

FI not only CAN work at a track, when done right it can DOMINATE



It's all engineering

I'm currently doing a blower upgrade on mine.
I can hardly wait!

69427

You certainly never polled me on that question. I've been running a FI (turbo) system for years. Constant boost gives a buncha low end torque coming out of the corners, and good top end power. (I hate to admit it, but my 355 is as fast as my big block.) I dumped the stock radiator for a decent performance unit, and along with the oil cooler and a decent front spoiler, it stays at a decent temp during track sessions. Horsepower means heat. Ya just gotta be intelligent about dealing with it.

John Shiels

I think it will be meeting the usual design parameters GM sets so it shouldn'r be any worse than any previous C5's or C6's which are stock on track.

mikahb

The Motortrend I just got with the ZR1 on the cover says they're in the process (I guess at article-writing time) of putting it through GM's "motorsports torture test" including 250 autocrosses and a 24-hour endurance test.

Seems like too much HP for me though - not many non-race cars can put 620+ hp to the ground effectively. Maybe on race rubber (345's?) it'll be better, but that's still a lot of HP for a front heavy (52/48) street car, IMHO.

All that said, DAMN it's purdy!

BrianCunningham

Any pics of your setup?

I've love to see it.

2000BSME

I was really hoping to hear more opinions on this subject...

yakisoba

Every home brew blown car I've seen at the track has had issues. Turbochargers seem to have better luck, but they still have heat issues.

There is one guy that I've seen with a twin turbo C5 setup that worked well, but it was VERY well done and the engine set up was expensive. The car ended up burning in the trailer, and he's now gone with a NA LS7.

I think that it's the nature of the beast: FI is seductive. Bolt on horsepower that works in combination with your headers and so forth. It's just not that simple. The engine has to be designed with FI in mind, and even then there can be issues.

95jersey

I don't know much about the ZR-1, but doesn't it have some new radical design Eaton supercharger? Maybe low heat was one of the benefits of the radical design? It also has a large intercooler and low compression motor.

Also, I have been doing research into choosing a future track car a year down the road and looked at the Lotus. They come with Superchargers factory stock and lots of folks are adding them on without any problem at the track. I talk to guys on the Lotus forum who do 20 track days a year with a supercharged Elise and no problems. So, who knows, only one way to find out...

NoOne

yeah but 320 supercharged HP in an Elise is a LOT less heat rejection than a 600hp SC HP.

We ran a turbo on our Miata, 320hp and no problems but the turbo sat up by itself, wasn't tucked away where it could melt things.

69427

I've been running this setup for about fifteen years. Started with autocrosses while I got things roughed in, and then it's had a couple thousand track day miles put on it since. Tore up the Doug Trash 4+3, so I'm running a Richmond six speed now. The engine is an 8:1 355 four bolt main with Brodix heads. (It's also painted the correct color for a Chevy engine in a Corvette! ) The fueling is handled by a boost referenced TBI off a 454 truck (2 inch throttle blades). The exhaust system is 3 1/2 inch 304 stainless, all mandrel bends. A few items are due for an upgrade, as I'm using the stock '84 ecm (re-cal'd) and the turbo is at its efficiency limit I believe. It's non-intercooled, but I used to run 30% 115 octane ethanol aviation fuel in it to cool the intake mixture. (I cal'd the BPW to be rich at WOT to use that combination.) The Dewitt radiator was a significant improvement, as I couldn't band-aid the stock radiator enough to get the job done. I also plumbed in an Accusump after losing oil pressure in a couple of autocrosses early on. No problems after that. I still have several instrumentation wiring harnesses (WBO2, EGT, ESC, pressure guages) on the engine while I've been tweaking the fuel and spark tables. (The car has been on the update backburner the last few years while I've been putting a C4 suspension on the spare frame for my '69.) It isn't the highest tech Corvette around anymore, but there weren't many examples to look at when I built this in 1992.

NoOne

Thats a nice setup but not to poop all over your parade that is a lot different than a current C5.

I guess I should be more clear myself in my statements I was talking about C5/C6.

Doesn't look like you have AC, thats a biggie, no condenser blocking the rad. Your turbo sits up and out of the way, not an option on the C5.

Yours works for obvious reasons but that setup you have cannot be duplicated in a C5/C6, plus the 115 octane to act as your IC doesn't hurt either. If you add a IC in the C5 your losing more cooling ability.

Again I should be more clear. I'm talking about a DD TT car in the 550rwhp range that I can drive to the track, run all day, and drive home with the AC on at 27mpg. A more purpose built car with no AC, runs on 115 octane, etc is a lot easier to do than a true DD.

I'm just interested to see how Chevy is going to manage the heat and other things that will come along with the ZR1. My buddies Cobra after a lap or two you can cook on the top of the intake.

yakisoba

I've heard only two things about the LS9 that might make a difference:
1) The intercooler and intake are the same. Integrated.
2) The rotors on the blower are four lobed, rather than two.

Your goals are lofty, but that's a good thing. Heck, I'd love such a car too.

69427

I've run against (kit car) Cobras before. They can run quite well. But, there's nothing under the hood other than engine most of the time. Why can't your buddy put some decent coolers in that thing? Shelby could make them fast and durable. What's your friend's explanation for not being able to do the same thing forty years later?

NoOne

Sorry when I said Cobra I meant Mustang Cobra, the SC'd factory cars from 03-04.

Applied engineering and $'s are two different things.

Your at 9-10K to build a reliable 4-5 a summer track car engine at 450rwhp-500rwhp with torque to match like a 402-416 stroker.

Your at 9-10K to build a reliable 550rwhp street car w/ turbo's.

Now to get that 550rwhp turbo car to be reliable at the track day level without overheating is the trick.

APS's kit does better with cooling since the intercoolers do not block the rad...instead they block the brake ducts, just as bad.

TTi's kit doesn't block the brake ducts...it blocks the radiator...again just as bad.

Your turbo is up top easy to manage heat even after long sessions. Turbo's tucked underneath where they make the bellhousing nice and toasty(and the C5's great hydraulic clutch setup) along with the oil pan in a car that is designed to have even under car airflow makes it difficult to manage the heat.

Putting that condenser in front of the radiator really hurts a cars ability to cool so not having AC, if your used to it or not, is a huge benefit.

At some point in time its just easier to put a Warhawk or something else in there for NA power.

Then again thats unlimited budget and time. For those of us with a budget, and a limited one at that the developements that GM has come up with to make the ZR-1 track worthy and FI will be good and cheap info for those of us without the big dollar budgets and that really was the overall point of the post.

96CollectorSport

Well said NoOne

We seem to have a FI thread on this board every month.
They all seem to have the same info, a bunch of guys say it won't work and a few guys disagree.

The big reason FI isn't seen much at the track is because it's not cost effective. To build a LSx motor that could handle track duty would start with buiding up a short block that has forged internals, then drop the compression, then add cooling (which for a track car is kind of a push since you should do the bigger radiator with oil cooler on both cars) then you add the price of the blower. Now instead of shelling out the $10k on a well built 4XX ci LS you have closer to $15k to $20k. Even the Lingenfelter cars I have seen at the track have had heat issues. If you go FI it's going to cost more than N/A. And with some of the new pieces coming out of GM these days (on both sides of this fence) it may take a little time to figure out which ways is best.

Also power levels for both options are going to be pretty similar (in RR trim) obviously you can crank the boost and put down some crazy 700 to 800 rwhp. But to last at the track the FI car will be under 600 rwhp.

I think the ZR1 will work just fine at the track, it has a more efficient supercharger (as stated before it's a 4 vein rotor design), they have oil squirters to cool the pistons and increased oil capacity from 8 to 10 quarts, they have 2 intercoolers integrated into the intake, and they started with a 6.2 liter instead of the 7.0 liter.

All in all I think that Vettes should be N/A, until the ZR1 (with the exception of the Callaways) all Vettes have been N/A. They show how well a front engine, rear wheel drive car with big cubes and lots of torque works well and stands the test of time and is a hard combo to beat.

NoOne

I've never driven a big cube LS1 except a first year 383 and the first year LS1 stuff was pretty poor.

I've had 2 Ls1 head/cam cars and a twin turbo car. Just like a turbo car. I enjoy driving it but I enjoy tracking the car.

So it would be nice to be able to do both, again the point of this post, what GM is going to do to make it live.

Oil squirters are a big thing. The Miata has them and really helped with FI. Of course it also helped that the Miata 1.8 came out of a FWD Turbo car in Japan...they just bumped the compression and took off the turbo.

I wonder if the ZR-1 oil squirt system can be retrofitted.

The maggies seem to do ok but I'm looking for more than 450rwhp for the street. It'll be interesting to see the price of the SC at the dealer once the car is out.

The KB seems decent but the hood kills it for me.

With a turbo I can turn it down to 450rwhp for the track and 550 for the street. I drove a 600rwhp car everyday for over a year and its more than streetable.

Another part of this post was if we can adopt what GM has done the millions they spent making this work is going to produce a lot more than me doing it on my own

BrianCunningham

Thanks for sharing





BTW Weeee!!!!!!