Driving Impressions: Part Deaux

[parsonsj]

Those are scary stories (but awesome!). Cars spinning tires at 80 mph! Amazing.

I don't have the 800+ hp of some of these unnaturally aspirated beasts, but I've never driven a high hp car before so I'll be damned cautious at first. I definitely want to live a while longer.

I hope Steve is right and my car's stance, air dam, and rear wing will keep the car civil at high speed. But it's not as if I did any wind tunnel testing. Who knows? Maybe I need to make a bigger wing for the back.

jp

[Blown353]

The high-hp is a mixed blessing John. I'd love to experience it at slower speeds, but the fact of the matter is I can't hook up until about 80. That means for me to really feel the thing pull I have to do 80+ mph hits. That's not very safe or sane-- things happen fast at those speeds, and the consequences of an error are much higher. This holds true for just about everyone making big hp numbers and running it through street tires. You just don't have the traction to use the HP at a reasonable speed.

I find it's a lot easier to make stupid amounts of horsepower than to find the traction to use it all. I would love it if I could stand on it from a dig, or even 35-40 mph and have the sucker hook up and then shut it down at 80 or 90; I would have my "fix" at that point and get on the brakes and return to reasonable speeds. Right now with my traction issues I have to wait until 75-80 and then ease into it. I usually do my "fun runs" starting in 3rd at about 75-80 and then run it to the top of third (115mph). The problem is by that time I want more fun, so I upshift into 4th and keep going part way into or sometimes to the top of 4th, which is 155 mph. It gets there so fast I don't realize or think of how fast I'm going and what could happen until I'm slowing back down.

Why can't I push a button on the steering wheel and have super-duper traction tires like Speed Racer had on the Mach V? That would solve my problems.

My next tire change I want to try either drag radials or road-racing tires out back. Hopefully that will allow the car to hook at a lower speed and allow me to have the same amount of fun but end at a lower terminal velocity.

As Steve stated, lift is also a big concern. I know for a fact my car gets very light in the nose above 165 or so, light enough such that I dare not venture into that territory anymore. The simple fact is our cars were never intended to achieve these kinds of speeds, and something has to be done to help mitigate lift and aid stability at high speeds. John has a good start with his chin and rear lip spoilers, but real world or wind tunnel testing may prove them to be either beneficial or harmful. A gut hunch and some virtual-CFD diagrams in my head makes me think they will help. How much, I don't know. Let us know when you get it on the road John!

Troy

[parsonsj]

Troy, I appreciate the insight about what that kind of horsepower means. I'm still trying to wrap my mind around it.

Man, I'm dying to get my car on the road. I'm figuring on 600+ hp from a 427 LS2. Just normally aspirated ... no positive atmosphere or anything. My tires are Pirelli PZero Corsas. Like I said before, I really have no idea how it will behave at any speed. I'm thinking the fun is finding out. Can't wait!

jp

[Y-TRY]

It was definately a wake-up call. I think it was a combination of the tires getting loose and lift that caused it to pivot like it did.

It's a fun story to tell, but I want to avoid things like that in the future. Otherwise you'll have to read it on my headstone.

I even thought I was being pretty conservative. I hardly stabbed the throttle. But the power-curve from the turbos with the stretched-out gears really lets the power sneak up on you. It feels totally different to me than high-hp naturally aspirated and juiced cars.

The moral isn't for everyone to go try and see if they can do it, too. The moral is to be very careful.

[Steve Chryssos]

Was your banzai run made without a front spoiler? If so, please install one ASAP--be sure to get the brackets that go with it and re-test (with helmet on)

Post results here. Thanks.

[Y-TRY]

Originally Posted by streetfytr68

Was your banzai run made without a front spoiler? If so, please install one ASAP--be sure to get the brackets that go with it and re-test (with helmet on)

Post results here. Thanks.

Yeah, no spoiler at the time. I have a new spoiler and the brackets but I can't get them to line-up for some reason. Anyone have a diagram of how they should go on? It seems pretty simple but the side rods don't even come close to lining up with both the spoiler and valance holes. The center one won't work because I notched the valance to make room for the up-pipe.

Looks like I may have to fab one out of a solid material, but I'm sure it will last maybe a month before just being scraped off.

[Payton King]

You may have one for a 69. 67 and 68's are not as wide but look exactly the same.

[Y-TRY]

Thanks Payton, I'll look into that. I ordered it from Year One, but this one does seem to be a bit narrow. The braces don't reach from the holes in the fender extensions to the holes in the spoiler. I never knew that the '69 was narrower and that could be the problem.

[Blown353]

Am I the only one that thinks a nice fabbed brushed aluminum chin spoiler would look better on the front of that Camaro than a black plastic factory piece?

I've been working on one for my car out of .125" or .188" thick 6061-T6 that will bolt to the bottom of the radiator support and the front frame horns. I just haven't made one that makes me happy yet. I whip up a flat pattern in CAD, use our NC cutting machine to cut one out of thinner stock for ease of use, then tape it on the car and stand back and look. So far I haven't got it quite right; I've been playing with various rakes and height tapers trying to settle on something I like.

When I decide on one, I should whip up a little model of the car and the chin spoiler and take a drive over to my alma mater, instrument the sucker and throw it in the little wind tunnel and get some data. I'd prefer it be effective rather than just cosmetic. I'm not a big fan of cosmetic-only mods...

I'd love to park my whole car in the giant wind tunnel at NASA's AMES facility (I have friends there) but I don't make enough in a year to pay for the electricity to fire that thing up for 5 seconds... it's rather expensive to power up 6 electric motors that make 22,500 horsepower... EACH.

[Steve Chryssos]

That's what we're here for. Let's have a looksie. Don't be shy now. Post a picture.