[forcefedcobra]

Originally Posted by dcook_14 I'm getting absolutely railed on SVTP for not wanting to go to IRS I'll post the link in a bit

LOL! to each their own. I LOVE my fulltitlboogieracing.com prepped IRS. It handles great on the road track and I have no issues drag racing it. Everyone talks about "wheel hop" and being afraid of breaking a half shaft but it wont be an issue if you run a slick at the strip. I'm running a 16x10 wheel and 26 inch MT ET Streets and have had zero issues with 5k rpm dumps at the strip. I plan to go up to a 28 inch slick in the future.

It's up to you and your budget IMO.

[Diabeetus]

And how much did you spend on that super nice IRS setup? And I really mean super nice, Ive seen them.

[89StangGT]

Originally Posted by ReverendDexter Why do you say that? Only reason I can figure is that most torque arms aren't rated for the amount of torque a built engine can produce. The geometry though, is much better for acceleration than a 4 link... well, at least a stock 4-link. Start mucking with control arm attachment points and lengths, and you should be able to get pretty dialed in (and change for track conditions). ------ If you do go IRS, make sure to get aftermarket bushings for where the IRS subframe attaches to the chassis. From what I understand, most of the problems people experience with the IRS are due to the subframe being able to squirm, throwing off all of the rear geometry..

Beat to me to. I read that post and was like ?

People have gone like 6s on Torque Arm suspension. It's a proven setup. I love mine on my LS1 car.

I also love my IRS on my Cobra, but I don't drag race it like I do my Camaro.

[dcook_14]

Originally Posted by forcefedcobra LOL! to each their own. I LOVE my fulltitlboogieracing.com prepped IRS. It handles great on the road track and I have no issues drag racing it. Everyone talks about "wheel hop" and being afraid of breaking a half shaft but it wont be an issue if you run a slick at the strip. I'm running a 16x10 wheel and 26 inch MT ET Streets and have had zero issues with 5k rpm dumps at the strip. I plan to go up to a 28 inch slick in the future. It's up to you and your budget IMO.

I'm curious to know how much you spent on the IRS as well, can't find much for prices online.

Are you saying on a stock IRS wheel hop/half shaft breakage won't be an issue if I run a slick, or are you saying a built IRS won't have wheel hop/half shaft breakage?

[forcefedcobra]

here is a link to Bruce's web page for all the info you could want. Not only is his kit IMO the best you can get but Bruce is also a top notch guy that knows his stuff and is willing to help with every step of the process.

Full Tilt Boogie Racing Homepage

I have more than just his bushing kit on my car but I also like to road track it so I have some of his other goodies as well. The most important for you would be the irs bushing kit. It coupled with some slicks will be more than enough for some solid street/strip duty.


Bruce's bushing kit will reduce wheel hop. A set of slicks will reduce wheel hop. The two together is even better...........

I've never understood why people spend $1k+ for halfshafts that end up having more issues than what they are worth. Even with expensive halfshafts you are liable to break something if you are trying to dump the clutch on street tires and even DR's. A 26 or 28 inch slick will absorb some of the shock from the launch and will keep even stock halfshafts happy and healthy. No matter what you have to pay to play. I would rather have a better handling and feeling irs for the street/strip/road track than a set of expensive halfshafts that have constant bearing issues and wont improve the weakest link in the irs (stock crap rubber bushings.

expensive halfshafts wont save you from this...........bruce's bushing kit will.

[ac427cobra]

Originally Posted by dcook_14 I've got an IRS out of a 2003 Cobra, and I was wondering if you guys think I should swap out my SRA for the IRS. I'm more into autocross and twisties, but I will drag it about twice a month in the summer. I'm worried about setting it up more for twisties and then having problems with wheel hop when I drag it, and snapping a halfshaft or breaking a diff cover. I wouldn't have to worry about wheel hop with the SRA, but I also want to upgrade to a 31 spline carrier, strong axles, and steeper gears. The IRS has all of those already. I've already got some solid opinions from 2v guys, but I want opinions from the 4v guys as well. Fire away!

If you're more into autocross will benefit more from the IRS.

If you remove all of the factory rubber in your IRS assembly, you won't have to worry about breaking halfshafts. You will however still need a rear cover brace if you're doing any amount of drag racing.

Originally Posted by dcook_14 Hahaha, people over on SVTP get all pissy when you say bad stuff about the IRS. From what I've gathered the built IRS and built 3 link SRA are going to perform about the same on the twisties, except the IRS can handle dips and bumps better and the ride of the IRS is a little better. But it's a muscle car, not a Lexus. I don't want to be scared to go to the strip, so I'll stick with the SRA and throw in coilovers if I want a better ride.

That's because SVPT has a lot of hard core IRS people. IRS and SRA won't perform the same in the twisties. The IRS will handle better. The SRA won't ride as nice and coil-overs will give you a worse not better ride. It will however 'perform' better from a performance perspective and allow you to corner balance your car. But it surely WON'T ride better!!!

Originally Posted by dcook_14 I'm curious to know how much you spent on the IRS as well, can't find much for prices online. Are you saying on a stock IRS wheel hop/half shaft breakage won't be an issue if I run a slick, or are you saying a built IRS won't have wheel hop/half shaft breakage?

Rubber in the IRS assembly and wheel hop is what breaks halfshafts, not power. Stabilize the entire IRS assembly and run a tire with a softer sidwall to absorb launch shock and you won't break halfshafts. There are many people running our bushing kit with WELL North of 600 RWHP running on OEM Terminator halfshafs with no issues.

FWIW

[ReverendDexter]

Originally Posted by ac427cobra coil-overs will give you a worse not better ride. It will however 'perform' better from a performance perspective and allow you to corner balance your car. But it surely WON'T ride better!!!

I'm curious as to why you say this. By the geometry, rear coilovers have the spring located closer to the wheel, meaning the spring rate can be lower to retain the same wheel rate. That means a softer spring for the same performance, which means better ride quality.

What am I missing here?

[ac427cobra]

Originally Posted by ReverendDexter I'm curious as to why you say this. By the geometry, rear coilovers have the spring located closer to the wheel, meaning the spring rate can be lower to retain the same wheel rate. That means a softer spring for the same performance, which means better ride quality. What am I missing here?

People typically upgrade their cars to a coil-over suspension first for performance purposes (better cornering without severe leaning and the ability to corner balance) and secondly for aesthetics. (lowering)

Your car came from the factory with soft springs and cushy dampers to give you a nice comfortable ride free of NVH. This is good for cruising the freeway and city streets but not good for performance and handling. This is why a stock car leans like a Chris Craft going through corners. In order to improve performance you're going to have to go to a stiffer spring to get your car to corner more flatly through the turns. With a stiffer spring you're going to have a damper matched to the spring, which will result in a stiffer ride. The higher performance the suspension is, the stiffer the ride will be. Some people think you put a heavier sway bar on a car for better handling and nothing could be further from the truth. A sway bar is a tuning tool not a suspension band-aid.

FWIW

[M.P. Cobra Fan]

AC, welcome to the board. Good to have you here. I enjoy reading your posts on SVTP.

[ac427cobra]

Originally Posted by M.P. Cobra Fan AC, welcome to the board. Good to have you here. I enjoy reading your posts on SVTP.

Thank you! Glad to be here!

[forcefedcobra]

Originally Posted by ac427cobra Thank you! Glad to be here!

I'm glad you are here too Bruce! I wont have to work as hard now. LOL!

[ReverendDexter]

Originally Posted by ac427cobra People typically upgrade their cars to a coil-over suspension first for performance purposes (better cornering without severe leaning and the ability to corner balance) and secondly for aesthetics. (lowering) Your car came from the factory with soft springs and cushy dampers to give you a nice comfortable ride free of NVH. This is good for cruising the freeway and city streets but not good for performance and handling. This is why a stock car leans like a Chris Craft going through corners. In order to improve performance you're going to have to go to a stiffer spring to get your car to corner more flatly through the turns. With a stiffer spring you're going to have a damper matched to the spring, which will result in a stiffer ride. The higher performance the suspension is, the stiffer the ride will be. Some people think you put a heavier sway bar on a car for better handling and nothing could be further from the truth. A sway bar is a tuning tool not a suspension band-aid. FWIW

So basically what you're saying is it's not that coil-overs are inherently worse riding, but that when people install them, they up the spring rates at the same time, causing the ride quality to be degraded.

To say that all coil-overs decrease ride quality would be a misleading statement, then, as it has nothing to do with the configuration of the spring, but the spring rate itself.

[ac427cobra]

Originally Posted by ReverendDexter So basically what you're saying is it's not that coil-overs are inherently worse riding, but that when people install them, they up the spring rates at the same time, causing the ride quality to be degraded. To say that all coil-overs decrease ride quality would be a misleading statement, then, as it has nothing to do with the configuration of the spring, but the spring rate itself.

Even with a C/O at the same spring rate as OEM and same dampening as OEM, (which would be a complete waste of money IMHO) your NVH will increase because the car was not originally engineered to be sprung from the new area it's being sprung from on the C/O's. I would consider this a decrease in ride quality.

[ReverendDexter]

Originally Posted by ac427cobra Even with a C/O at the same spring rate as OEM and same dampening as OEM, (which would be a complete waste of money IMHO)

I agree with this... what I'm disagreeing with I think is just a matter of semantics, not engineering.

[dcook_14]

Wow glad to see you on this site as well Bruce. I feel much more at home here than on SVTP