which one is better? 99' vs 01'

[CobraRed01]

I'd go for a good low miles 99 because I like the Tremec built T45 better than the 01's 3650 - especially on the road course. The IRS issue is easy fixed - pick up a complete 03/04 IRS unit for under $1000 (there are several for sale at any given time on this site for that money), spend a few hundred improving it, and then sell off the old 99 unit for $400 - $500. Another $3000 for a pair of 2000R seats and the 2000R front splitter, and you've got one badass Cobra for about the same money as a used 01!

A quick Q for oz98snake. I've been planning on upgrading my 2001 IRS with the usual parts to tighten it up. I was wondering why you would recommend the 03/04 IRS and then spend money upgrading it as well? Is there something about the 03/04 IRS that I wouldn't be able to match with aftermarket parts? I understand the 03/04's tighter "right out of the box", but I didn't think other than halfshafts, firmer bushings and the IRS brace (which are all available for 2001 aftermarket) it was any different.

 

[oz98snake]

A quick Q for oz98snake. I've been planning on upgrading my 2001 IRS with the usual parts to tighten it up. I was wondering why you would recommend the 03/04 IRS and then spend money upgrading it as well? Is there something about the 03/04 IRS that I wouldn't be able to match with aftermarket parts? I understand the 03/04's tighter "right out of the box", but I didn't think other than halfshafts, firmer bushings and the IRS brace (which are all available for 2001 aftermarket) it was any different.

You're right, there isn't any different apart from what you mentioned - the "upgrades" that I was alluding to - and would recommend for any IRS Cobra - are to at least change the IRS subframe and differential bushings out for urethane (or aluminum if it's a race car or serious street machine where NVH isn't a concern).

I would also recommend strengthening the upper (rear) IRS subframe mounting bracket - if you have ever had your subframe out or lowered, you can see just how poor this bracket is because you can flex the outer side quite a ways with your hand!! Kenny Brown addresses this problem by dispensing with the bracket and upper subframe mount altogether, and replacing it with a custom bracket with no bushing that is welded to the IRS subframe. A much simpler and way less expensive solution is to do the "Steeda" mod - a simple reinforcing gusset plate welded to the mount bracket and bolted to the body - it is almost as effective as the KB solution, and perfectly adequate for street driven Cobras or occasional open trackers: http://www.steeda.com/store/-catalog/IRSsubframebracket.htm

The other problem area with all IRS models is the control arm bushings, especially the UCA (upper contral arm) bushings as strange as that may seem. The reason is that the OEM UCA bushing design causes a lot of binding - in fact, we have found that there is usually over 20lbs of force needed just to move one UCA! With properly installed urethane bushings in the UCAs, you will find that the ride quality actually increases over the OEM bushings because of the eliminated binding. The good news is that the UCA bushings are a piece of cake to switch out. The lower CA bushings don't seem to usually have a binding issue, but of course excessive deflection of the rubber is an issue when a car is open tracked just as it is on the front LCA bushings. The 03/04 Cobra does better in this regard as the large rear LCA bushing is 50% stiffer than the 01/99.

 

[oz98snake]

Almost forgot, there is one other weak point in the the IRS - and this one will almost certainly become an issue on a car that is open tracked, or eventually one that has had all the bushings replaced with stiffer ones.

The rear spindles have a kind of spherical bearing top and bottom on either side instead of ball joints - these are sealed greased units with a nylon bushing liner - and they are not up to the task when pushed hard on the track, or when all the soft shock absorbing rubber bushings have been replaced - the nylon liner deforms or fails and they become "loose" and/or the rubber boots fail because of heat from the brakes during track use, and they dry out.

These are not available from Ford - you have to buy the whole spindles for over $450 per side!! Although Steeda has threatened to release an aftermarket alternative for some time, but still say they are at least some months away, so the only off-the-shelf solution available right now is via SHM - it requires shipping of your spindles to them, and cost around $1000! I made my own using racing grade greaseless PTFE lined spherical bearings in custom machined bearing shells for a whole lot less than SHM's solution. I'm sure my machine shop guy would be happy to make up some more if anyone else needs a set?

 

[CobraRed01]

oz98snake...thanks for the new information. Is the LCA bushing on the 03/04 IRS actually larger or just stiffer? Sounds like you do a significant amount of open track, how would delrin or polyurethane bushings hold up under normal daily driver use (i.e. hot and cold weather, rough roads, etc.)? Do these bushings ever breakdown or need replacement under this kind of use (abuse)? Would they do 60K miles without replacement?

The IRS bearing issue is something I haven't heard before. Considering the cost to fix this, I see why many switch to SRA for hard track use. Probably the cheaper route. Despite its problem I think the stock IRS in my 2001 does pretty well for aggressive street use. It's kind of a "flexiflyer" but it does feel more firmly planted than an SRA on the twisties. I don't drag race as a rule....so wheel hops not an issue. I aiming for a tighter IRS with some limited track use, so durability is going to be important. Probably would do most of what you recommend except the bearings and aluminum bushing route.

 

[chuckstang]

oz96snake
OUTSTANDING INFO!!!!!!!

 

[oz98snake]

The LCA bushings are the same size in all Cobras - the 03/04 just has a higher durometer - stiffer - rubber bushing. It also has a stiffer bushing in the front LCAs as well.

The Delrin/Aluminum bushings last really well on the street - they have grease nipples, and therefore can be kept well lubricated. Urethane is not going to last as long as Delrin/aluminum - just how long depends on how hard you abuse it, and how well you maintain/lube it - certainly more than 60,000 miles if well maintained. Zerk grease nipples don't seem to work so well with urethane bushings in my experience, so best just to pull the arms once every year or two and relube them with the high adhesive special grease available from Energy Suspension or Prothane - it's a messy job, but not difficult, and you can inspect them for wear while you are at it.

and thanks chuck.

 

[oz98snake]

....
The IRS bearing issue is something I haven't heard before. Considering the cost to fix this, I see why many switch to SRA for hard track use. Probably the cheaper route. Despite its problem I think the stock IRS in my 2001 does pretty well for aggressive street use. ....

Well, I installed an IRS in my 98 specifically for hard track use, but I also wanted to maintain some semblance of ride comfort since it is also a daily driver, and the IRS achieves this dual purpose compromise better than any built live axle can - period! Is the IRS faster on a road course than a good live axle setup? (by good I mean with a torque arm/panhard or at least a Steeda 5-link) - not on most tracks - bumpy ones like Hallett in Oklahoma maybe? But as one top American Iron driver put in when he drove my car last year: "I don't think it is faster (than his Griggs live axle), but it sure is easier to drive at and beyond the limits!"

And remember that the 8.8 live axle has issues with track use as well - the side loading is taken by the diff carrier bearings, and they get chewed up, so serious racers often convert to a hybrid wheel bearing setup using the 9" style outer parts with the 8.8" diff. The reality is that no matter what suspension and drive train you have - it cops a hiding on when driven on a race track and needs improving over OEM.

 

[CobraRed01]

oz98snake...thanks again.

 

[Serpentor]

good info oz...
I got the MM Delrin bushings on my rear control arms, and I'm going to put grease fittings on them one of these days. I'll post the pics when its done.

 

[Niteninja]

When I was looking at the decision for a Cobra. I was faced with a 99 vert(rollcage, and some mods...but felt tired 60K miles) , and an 01 vert(flowmasters, and felt new 50k miles). The 99 was going for $19.5K and the 01 was $18K and that was last August. I went with the 01. and I haven't looked back.

 

[Thunder5.0]

99's have t-45's. Most feel the they shift better than the t-3650's.

 

[CobraSvt9746]

01's have amber in the taillights

but they both come with the weakest cobra hood ever

 

[cobra2798]

99's have t-45's. Most feel the they shift better than the t-3650's.

Anything shifts better than the 3650.

 

[chuckstang]

01's have amber in the taillights

but they both come with the weakest cobra hood ever

nope the 94/95 cobra has the weakest hood ever because it is exactly the same as on the gt's.

 

[Rick James]

nope the 94/95 cobra has the weakest hood ever because it is exactly the same as on the gt's.

Dude, the 99/01's share the same hood as the V6's!!!!

 

[cobra2798]

Dude, the 99/01's share the same hood as the V6's!!!!

I hear ya! after lowering springs thats the next cosmetic mod for my car. I hate the cheesy hood i think a 00 cobra r would look much better or even just a 99-04 cowl hood.

 

[AzDropTop]

It's not, unless Marek was talking about the cheapass bolt-on subframe connectors that 01+ 'verts got (courtesy of the Bullitt), but they don't do anything and should be dropped for a set of welded connectors ASAP. Other than that there were no chassis tweaks to them.

My 99 had them too?

 

[Scott Kim]

$4000 buys a lot of mods including leather recaros (which are miles better than the '01 seats that everyone seems to be in love with) If the difference in price is that high, just have custom seats made like I did. I'm not saving this car for a garage queen to sell later. I'm interested in driving it and driving it fast. so with either car, you're going to have to make mods to compensate where Ford compromised. this goes for the interior as well (esp for seats and shifter) . . . . and other trim pieces if it's that important to you

and there are stronger halfshafts available for the stock 28 spline axle, so the arguments about having to change the differential as well as the shafts etc yada yada yada is irrelevant. they are identical cars, and the stuff that is different is pretty meaningless. . . . . . . . to me embroidered seats don't mean as much as they suck nearly as bad when compared to custom recaros that plant your ass to the seat like velcro when taking corners.

I bought this car new and it's been a blast every day, even when I was spinning a bearing at 8000+ rpm running 140mph+

 

[chuckstang]

Dude, the 99/01's share the same hood as the V6's!!!!

No, the v6's share the same hood as the 99/01 because we were first :beer:

 

[99COBRA2881]

01's have amber in the taillights

but they both come with the weakest cobra hood ever

Since its all just about the bling first and functionality second, the 99-01 hood falls short of some, but as for a functional heat extractor hood with some modification and removal of the fire blanket or minor trimming is made perfectly to pull air out of the engine compartment directly behind the radiator. 2881