IRS Camaros

[mfain]

Thanks Tyler. I'm getting closer -- built some longer LCAs for your ATS spindles and used a deeper offset front wheel -- that gave me a better scrub radius and allowed me to get a 315 on an 11 inch wheel up front with good turn radius. Also some interesting duct work for the oil cooler (inlet, diffuser, and air extractor/nozzle) and I'm finishing the underbody CF tunnels and belly pan. I'll get an update on my build thread soon. We need to get some of these IRS cars on the track, just for the sake of argument.

Pappy

[Vince@Meanstreets]

hey Pap, you have any build threads of your camaro project, love to see it.

Vince

[Silver69Camaro]

It's been said over and over that IRS cars typically only show a benefit over solid axles on bumpy surfaces, and ride quality is noticable on the street. IRS also allows you to adjust camber and toe, both of which are great things to have. But if you know what you are doing, you can do that on a solid axle as well. IRS setups typically wont have pad knockback issues either.

But, our cars just aren't packaged for IRS systems. If you want to chop the rear tin, go for it. Be prepared to run flat-faced wheels and narrow the IRS enough for the correct hub track.

If you want a all-out race car like Tyler, then I think IRS is worth considering. If it's a track day car, I wouldn't bother. But that's just my opinion.

[exwestracer]

I agree with Matt on this (and I'm a BIG fan of IRS). We did a 2nd gen Camaro here at the school awhile back. Full 2X3 frame recessed and welded into the floor, relocated upper control arms, and a complete Nissan 350 multilink IRS.

Track width wasn't really an issue with the Nissan setup, but getting the ride height down to 6" took a lot of cutting. Ditching the cradle might have helped, but would have meant a lot more setup and fabrication for all the mounts.

I've followed Teetoe's build, and they obviously started out with a gutted shell. Either way, it's not easy. Or cheap...

[mfain]

I have already completed the IRS in my car. I was just curious how any of the IRS PT cars were doing on track. I went with an IRS primarily to lower the rear roll center in an attempt to better "balance" the car with respect to front and rear roll angles under lateral g -- to make the rear of the car do more of the cornering work and to get better forward bite off a corner. Most of the new high performance stuff (Corvette, Viper, and even NASCAR) has taken this approach, using a lower roll center and stiffer rear springs and bars. You can also loosen or tighten the car at the track by changing the adjustable roll center. My car is not a Camaro -- it is an old previously straight axle Corvette, but the modifications are somewhat similar to what you have to do with a Camaro. I went with a highly modified C4 approach -- C4 bearing carriers with longer, adjustable forward four link (to minimize C4 roll steer characteristics and to make the instant center and anti-dive/anti-squat adjustable, something you can't do with a C5/C6 set-up without moving the control arm pick-up points); adjustable lower lateral link for both camber and roll center adjustment; a vertically adjustable toe link to fine tune bump steer; a bullet proof Tom's differential with "1000 horsepower" Drive Shaft Shop aluminum half shafts; etc. The body is widened six inches for bigger tires and to keep from having to narrow the suspension which creates too many angles during travel and affects camber gain. The rear tires are 345s on 13 inch wide X 18 inch HRE wheels. The front is equally as modified -- Woodward front steer rack, ATS spindles, custom roller bearing control arms, etc. As Tyler said, we have been working on our cars a long time with the hopes the effort will be worth while. Like Tyler, my car will be streetable, but with a bias toward the track.

Pappy

[CamaroAJ]

what has two thumbs and wants to see more pictures? this guy.

[Ron in SoCal]

Originally Posted by mfain

I have already completed the IRS in my car. I was just curious how any of the IRS PT cars were doing on track. I went with an IRS primarily to lower the rear roll center in an attempt to better "balance" the car with respect to front and rear roll angles under lateral g -- to make the rear of the car do more of the cornering work and to get better forward bite off a corner. Most of the new high performance stuff (Corvette, Viper, and even NASCAR) has taken this approach, using a lower roll center and stiffer rear springs and bars. You can also loosen or tighten the car at the track by changing the adjustable roll center. My car is not a Camaro -- it is an old previously straight axle Corvette, but the modifications are somewhat similar to what you have to do with a Camaro. I went with a highly modified C4 approach -- C4 bearing carriers with longer, adjustable forward four link (to minimize C4 roll steer characteristics and to make the instant center and anti-dive/anti-squat adjustable, something you can't do with a C5/C6 set-up without moving the control arm pick-up points); adjustable lower lateral link for both camber and roll center adjustment; a vertically adjustable toe link to fine tune bump steer; a bullet proof Tom's differential with "1000 horsepower" Drive Shaft Shop aluminum half shafts; etc. The body is widened six inches for bigger tires and to keep from having to narrow the suspension which creates too many angles during travel and affects camber gain. The rear tires are 345s on 13 inch wide X 18 inch HRE wheels. The front is equally as modified -- Woodward front steer rack, ATS spindles, custom roller bearing control arms, etc. As Tyler said, we have been working on our cars a long time with the hopes the effort will be worth while. Like Tyler, my car will be streetable, but with a bias toward the track.

Mostly, I build bucks (some are actually usable fiberglass parts, some are fiberglass over wood and/or foam), then I pull gelcoated fiberglass molds off of them. The molds are reusable, but mostly specific to my car. I have a few flat panel parts that I pulled straight off of aluminum sheet that served as more-or-less a one time mold. I have the wing, splitter, diffuser, trunk interior panels, lower splash pans behind the front tires, aero-farings for the back edge of the fenderwells, and I am finishing the molds for the underbody tunnels and the belly pan. I am going to build the aero-roof out of CF and will build a third rear deck lid with only the spoiler. Of the other two, one is clean (stock fiberglass) and the other has both the spoiler and the adjustable wing.

Pappy - everytime you post, I get more impressed with your build and where you're taking it. You're like a one man wrecking machine! Props man...get that bad boy on the road...(you too Tyler!)

[GregWeld]

At the risk of being bombed for jacking the thread... I just want to ask a dumb question...

Putting the IRS (Kugel Champ quick change) under the rear of my '32 was not done for handling -- I chose it for looks only.... Will I notice any handling improvements at all?? Not that a hi boy is a handling machine.

[Teetoe_Jones]

Originally Posted by Vince@MSperfab

hey Pap, you have any build threads of your camaro project, love to see it.

Vince

Originally Posted by CamaroAJ

what has two thumbs and wants to see more pictures? this guy.

Here ya go you lazy bastards. It's a Corvette though, not a Camaro.

https://lateral-g.net/forums/showthread.php4?t=21031
https://lateral-g.net/forums/showthread.php4?t=20865

Tyler

[mfain]

Thanks Tyler. I'll have new pictures soon -- lots of new CF pieces, new duct work for the oil cooler, subtle modifications to the body (functional air extractors), aluminum firewall for the fuel cell (damn regulations), etc. By the way Tyler, did you know you don't really need an autoclave if your garage is at 134 degrees?