what are the IRS "must haves"?

[myslowstang]

I'm a new owner of a 03 Cobra and it's pretty much stock except an upper pulley. I will be doing some drag racing at the strip. I will be using DR for now but my go to a slick later on. I know wheel hop is the main killer of the IRS and mine is completely stock.
What are the best ways to get rid of wheel hop with the IRS system? What are the "must haves" upgrades of the IRS?

 

[myslowstang]

So far this is what I'm thinking about installing:
BilletFlow IRS Brace
BilletFlow IRS Subframe Support Brackets
Delrin Upper Control Arm Bushings
Delrin Lower Control Arm Bushings
MM Full Length Subframe Connectors
IRS Heavy Duty Crossmember

 

[rudycobra]

Skip the brace and just do a lpw or frpp differential cover . Complete ftbr bushing kit and subframe connectors . Don't need the crossmember . Don't think it helps anything because cobras allready have one . Lot people will talk bad about drs but keep the low like 15 lbs and u should b ok . I ran 555 rs at 13 and pulled 1.72 60' consistently .

 

[JDUB348]

My IRS must have is getting a built SRA in its place

 

[myslowstang]

Ok thanks for the help. This IRS is all new to me but I do love my Cobra. It pulls harder then my Procharged 2V GT. I can't wait to throw more mods at it and make some more power!

 

[P49Y-CY]

if you're taking it to the strip, at least put a brace on, and if it starts to hop, stop!!

best of luck and have fun :rockon:

 

[tt335ci03cobra]

Ya great advice already. A sra swap is complicated for most but isn't necessary unless you wanna run low 9's or 8's. Guys have gone 9.50's and faster on an IRS it's just in the setup.

I'd recommend in this order:
-full IRS brace (pic a manufacturer you prefer)
-full tilt boogy racing complete irs bushing kit
-mm full length weld in sub frame connectors
-drag slicks (just a lot safer than radials unless you have a great idea of what your doing at the drag strip; rockon)

If you like taking twisties as well
-mm bump steer and tie rod end link kit
-mm coil overs (3-500# springs depending on how aggressive you like to get after the curves.)

The best question would be what are your goals for the car? Knowing this can help us help you out a ton.


(I've gone for 400# springs and a full maximum motorsports suspension but run drag radials (315/40/18) rears for traction being I have too much power for any other type of street tire. It handles really well and because of gearing can get solid traction but is more suited to a handling course than a drag strip)

 

[mr.magic]

get bias-ply slicks if you run slicks but your a bit down on power unless you really know how to work the clutch. Even if you bounce it off the limiter and side step it(bad idea n the IRS) you'll bog. Also if your intrested in simply drag racing save your money and do the SRA. The weight saving alone make it worth while and by the time you dump all the money into making the IRS drag reliable you've almost bought yourself a SRA. If you decide down the road to go with bigger half shafts you'll be way over a built SRA price.

Being that your almost stock though the FTBR set, BF Diff brace or FRPP diff cover, and a set of FULL length connectors should be more than good for your power level.

Also set your aside some cash for when/if you snap the input shaft so you can upgrade to a 26spline and new clutch.

 

[myslowstang]

Sorry I forgot to mention that I will be doing both drag racing and road racing. I want it strong enough for the strip but handle on the course. I plan on keeping the IRS

 

[Torched_03]

IRS Brace or Cover
IRS Sub Frame bushings Upper/lower
MM front SubFrame bolts and nuts.
Upper/Lower Dif Bushings


Thats a good start. If you not a serious drag racer or Rd racer I think the FTB kit might be over kill and for the price you coud do a SRA swap. I would also look into a set of slick just cause they are safer on the IRS than DR's.

 

[tt335ci03cobra]

If you want a car that hooks at the strip good (1.65-1.7 60' fts is sub 4 sec 0-60 which I consider good and a fair trade for a handling car.) then some slicks and skinnies coupled with these excellent handling mods in this order of importance will get you there.

(mm= maximum motorsports, ftbr=Full tilt boogy racing)

-ftbr complete IRS bushing kit (really cleans up handling)
-differential brace
-mm full length subframe connectors (flsc's)
-mm coil overs and camber plates
-mm bump steer and tie rod end link kit
-mm strut tower brace-great for tying the front end together
-mm solid steering shaft (no slop/no nasty plastic grommets)
-mm k member and a arm kit (excellent geometry, very useful frontal contact patch, ditch 40#'s off the front end)
-Detroit trutrac or any full limited slip differential you like. My trutrac is holding up to 800whp but it could just be my easy driving style. They are robust and handle great nonetheless.
-sticker tires once you know the car well-I run nitto nt05's.

You can also buy adjustable sway bars and end links, I haven't yet as I haven't felt a need but many say it's great for adjusting transitional rotation.

Good luck and feel free to pm me if you have any questions. Keep in mind I put those parts in order of effeciency/fun factor to cost ratio. Needless to say, a bone stock cobra is plenty fun on its own and a great place to learn the ropes of handling and braking technique if your not terribly familiar with it. That said if you have enough experience to be comfortable in a g machine, those mods will easily impress

 

[KINGCOBRA86]

Alignment!

 

[ThatOneCobra]

All I have on the rear end of my 03cobra is a BF Brace and some MT dr's 305/35/18 and I have no wheel hop. Mods on my car are jlt ram air,bassani x, and a catback. Since I hardly go to the track I dont think ill do much else to irs.

 

[myslowstang]

If you want a car that hooks at the strip good (1.65-1.7 60' fts is sub 4 sec 0-60 which I consider good and a fair trade for a handling car.) then some slicks and skinnies coupled with these excellent handling mods in this order of importance will get you there.

(mm= maximum motorsports, ftbr=Full tilt boogy racing)

-ftbr complete IRS bushing kit (really cleans up handling)
-differential brace
-mm full length subframe connectors (flsc's)
-mm coil overs and camber plates
-mm bump steer and tie rod end link kit
-mm strut tower brace-great for tying the front end together
-mm solid steering shaft (no slop/no nasty plastic grommets)
-mm k member and a arm kit (excellent geometry, very useful frontal contact patch, ditch 40#'s off the front end)
-Detroit trutrac or any full limited slip differential you like. My trutrac is holding up to 800whp but it could just be my easy driving style. They are robust and handle great nonetheless.
-sticker tires once you know the car well-I run nitto nt05's.

You can also buy adjustable sway bars and end links, I haven't yet as I haven't felt a need but many say it's great for adjusting transitional rotation.

Good luck and feel free to pm me if you have any questions. Keep in mind I put those parts in order of effeciency/fun factor to cost ratio. Needless to say, a bone stock cobra is plenty fun on its own and a great place to learn the ropes of handling and braking technique if your not terribly familiar with it. That said if you have enough experience to be comfortable in a g machine, those mods will easily impress

Yeah I wish I could upgrade all of those things but I don't have the funds for them right now. That's why I'm trying to figure out what are the things I need to have in order not to break something my first day out on the track. I'm not trying to get the best 1/4 mile times nor am I trying to get 1.5 60' times. I just want something to hold up to launches (probably no higher then 2K) at the track. I just go to the track for fun so I'd rather it handle better then have better 60' times.
So if I just start with the IRS bushing kit, differential brace, and subframe connectors I should be ok for a little while until I start adding more power right?

 

[rudycobra]

Yeah I wish I could upgrade all of those things but I don't have the funds for them right now. That's why I'm trying to figure out what are the things I need to have in order not to break something my first day out on the track. I'm not trying to get the best 1/4 mile times nor am I trying to get 1.5 60' times. I just want something to hold up to launches (probably no higher then 2K) at the track. I just go to the track for fun so I'd rather it handle better then have better 60' times.
So if I just start with the IRS bushing kit, differential brace, and subframe connectors I should be ok for a little while until I start adding more power right?

Yes u will b fine with that !

 

[Torched_03]

I lasted a whole season of racing with just a set of slicks on a bone stock IRS. Made 440/460. Just launched at 2500 with a bit of clutch slip. never once had wheel hop with slicks.

 

[TerminatorSVT03]

I've snapped my passenger side half shaft with a 2k launch an a nitto 555r dr so watch how you let the clutch out lol

 

[rudycobra]

I've launched at 4500 with stock IRS and 555rs and didn't break anything with 1.74 60' . But think clutch was slipping a Lil and actually worked to my advantage

 

[TerminatorSVT03]

I've launched at 4500 with stock IRS and 555rs and didn't break anything with 1.74 60' . But think clutch was slipping a Lil and actually worked to my advantage

Wow I must have bad luck lol

 

[Posi]

Skip the IRS Brackets. Personal experience.

OP if you want to race and not break anything get some big's n little's and let it eat with 28" slicks. The tall sidewall will soak up the hard launch and will also keep it from wheel hopping. Plenty of cars have went 10's with a bone stock IRS like this.

Get a brace or a diff cover it's a must a have. Same as full length subframe connectors as well.

Last if you're going to do bushings check out FTBR's kit. Best one out there.