While on Chevy Hardcore, came across this press release regarding 3rd gen parts that Heidts is bringing to the market this year.

Apparently they are serious - bolt-in IRS is on their plate for release later in 2015.

http://www.chevyhardcore.com/news/ne...-and-firebird/

 

DSE and now Heidts - I'll watch my car value creep up and maybe get near 2/3 of what I have in it.
I'll watch for those inner SFC - Alston's they say.

 

I'm interested in the IRS setup. Might be fun for my Ls1 Iroc.

 

Probably a minimum $7,500 investment?

 

http://www.heidts.com/part/67-69-and...ar-suspension/

First gen IRS setups are $10k.... definitely not cheap.

 

those Jaguar based IRS setups with the inboard mounted brake rotors have never given me a warm fuzzy feeling- the last thing you want if an axle breaks is to lose the brakes, too..

 

Front brakes do most of your stopping. Its not that big of a deal

 

it is if you break the axle for some reason going hard into a low speed turn after a high speed straight on a road course.. and if you are going to all the trouble to put an IRS setup in your car, you should definitely be out on as many road courses as you can find as often as you can.

 

They are serious, but I had a chance to talk price points with them at Thirdgen Expo. I saw the stuff in the shop cars they brought, its a quality looking peice, and is already a 9" with a host of upgrades. So it'll handle the power.

But their price point is $9,000-$10,500 for the complete bolt-in unit. Thats just not conducive for the thirdgen market. Maybe in another 15-20 years it will be.

 

Flashy show car stuff. I would not waste my money. I could build something from scratch much more effective for less. Lower forward links are far more stable. I prefer the factory 3rd gen rearend.

I am not a fan of companies like this. I am currently helping a friend sort out issues with TCI crap (Total Cost Involved) show car stuff on a 67 Nova he built. I went to set it up for him and was like WTF? The geometry is all wrong and I have a rep coming to look at the **** poor fitment and geometry angles this week. They will need to re make the 4 link bar lengths. COPmpanies like this often do not know what the heck they are doing. In other words- I would not be their guinea pig.

 

I was told the plan to have their irs be about half the cost as their normal Irs set ups. I have been looking into this IRS for some time now. I have so much money in my car I figured I might as well get this next for my car, trying to set my car up for autocross anyways.

 

Since it comes with a 9", I can see an acceptable premium over the cost of doing a 9" axle swap. But thats not what I heard when I was talking to them in person.

Like I said, the materials work was nice, the parts looked good. But I don't think it lines up with what most thirdgen owners are willing to pay. So it won't sell in high numbers.

 

I'm no expert of the autocross class structure, but putting an IRS into a solid axle car is going to push you up quite a few classes - probably into one that you won't be competitive in.

Although some of the fully built pro-touring cars (1st and 2nd gens) can do well on IRS conversions, it is a huge investment to do it correctly - not counting any other parts you will need.

 

Actually looking to be competitive, my car is nearly setup for autocross with all the parts I have on it except I am also switching to a 6 speed as well.

 

At a bumpy autocross it will help quite a bit but on a smooth track it will not be a life-changer.

 

I don;t care what parts someone bolts to a car- If people do not have the knowledge to know haop to set up those parts, balance the old front RC with the new rear suspension RC, and tweak and tweak , and tweak in testing, then this is in no way in helll ever gonna beat a factory type 3rd gen platform.

Why do I love these cars an still keep around them even long after I have moved on to other cars? It is because the more and more life goes I can confirm just how good the 3rd gen platform is to work off of and how lucky GM got with the unibody car with these suspension points. The only thing they messed up (which they never cared about) is the ability of "hot rodders" to modify these cars with wider tires and make the ackerman work. The cars do great with weight reduction and factory sized tires up front- I have proven this with a 3100 lb car on street tires pulling 1.07 g's.

I did better then Guldstrand and Herb Adams ever did in their shootout. (For the record, Dick Guldstrand is a life long family friend of mine)

 

That will bump you from ESP or CP to XP or EM. I'm going off memory so I'm probably off some, but EM max minimum weight is like 1950lbs, not a weight you'd ever get down to. XP minimum weight would be 2300-2400lbs and you'd be running against turbo charged small bore cars weighing around 1600lbs and not necessarily making any less power.

Other thing to keep in mind, an IRS setup won't have the antisquat of a well setup solid axle which is important when you're trying to put the power down out of low speed corners.

A serious CP car (not mine yet due to $$$) will have a full floating 9" with cambered axles. A 3 link seems to be the easy button, but I'm trying to make a decoupled torque arm work.

 

Hi, just to answer a few questions that have come up above regarding the Heidts IRS: price point will be about $7,000, much cheaper then our normal IRS options. Also, we will not be using inboard braking on this system due to the location of the gas tank. We have quite a few cars that do autocross and pro touring events, even some that are regulars in Optima events. This new IRS is being built to handle all the abuse the track can provide. We also do offer an adjustable torque arm, control arms, panhard bars and very shortly a new k-member along with adjustable coilovers.

 

$7k buys a lot of stuff to make the stock suspension work, while also leaving money left over to buy a bunch of stuff to make the car faster and safer...

 

What about the drive shaft? Wouldnt you want to change that up too to eliminate loss of power due to u-joints and flex/movement? Just make it stronger/more firm all around. Like a Vet...

yeah, 7k is a chunk of change. Im sure they will sell but not to guys like me. As stated above, a guy could do a lot to his car for 7k. However, not to many guys can say they have IRS in their 3rd gen.

That GS-90 is bad to the bones.

-Dan

 

So front-tranny Vettes also have torque tubes, not just the rear tranny models?

 

So is this new k-member good for autocross and road racing?

 

If the kmember has the same exact suspension mount tabs as the factory unit? then ABSOLUTELY nothing but lightening your wallet. A lighter Kmember does nothing for handling, in fact it will decrease the ride ratio and negative roll weight being lighter which both work against better handling.

Save your money and keep the stock Kmember.

A change in A-arm mount height and a-arm shape can and will change handling characteristics- I highly doubt you are ready to spend money on all the parts needed to do this sort of change and then have understanding how to try and tweak it so it at very least is hopefully as good as what the facotry mount geometry is.

 

not really, they had a sort of an I beam looking thing that bolted to the rear of the trans and the differential that ran parallel with the driveshaft to tie everything together.

 

Thanks SlickTrackGod. For my turbo application, if it frees up some space, that would be good.

If I was going to start messing with the a-arm mount height and shape, I would probably clip the front with a double a-arm type suspension (vette)?

Was just interested in maybe gaining a little room around the bottom of the motor, but not for a weak drag type k-member.

 

I'm in the same boat. I need the space to run a 4+ inch downpipe but the car is not a drag car.