You want to know what an '03 cobra IRS looks like on a friday night?
Build Thread '83 T-top Coupe - Welding Holes in My Rear
- Thread starter Davedacarpainter
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- Jul 7, 2005
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Gone incognito.
Or its the totalled car guy making a comeback acting like he knows peeps.
Guess I should update this thread.
Here's the new to me 2003 Cobra IRS. Freshly drug home from Waco, Texas.
Thanks again to Matt @FoxMustangLvr for the tip on this IRS.
Here's the new to me 2003 Cobra IRS. Freshly drug home from Waco, Texas.
Thanks again to Matt @FoxMustangLvr for the tip on this IRS.
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Ok, i've got a question for y'all. Can I use a 2003 Cobra steering rack in my car?
If so, what special things do I need to do?
The guy that sold me the IRS is checking to be sure the rack is original to the car. Meaning a real Cobra rack.
If so, what special things do I need to do?
The guy that sold me the IRS is checking to be sure the rack is original to the car. Meaning a real Cobra rack.
- Mar 2, 2015
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You can use a cobra rack in a fox. It's not a complicated swap. Someone here did the swap recently.... I can't find the thread though.
A few year's ago I did one for a guy. I can't remember everything I did back then.
Basically, i can't remember ish....
I'm at the bar.....
A few year's ago I did one for a guy. I can't remember everything I did back then.
Basically, i can't remember ish....
I'm at the bar.....
You need this hybrid steering shaft from MM:
http://www.maximummotorsports.com/S...Power-Steering-Rack-1979-93-Mustang-P461.aspx
From memory, it seems like you either need to run SN95 length control arms or use shorter tie rods with the Fox arms.
http://www.maximummotorsports.com/S...Power-Steering-Rack-1979-93-Mustang-P461.aspx
From memory, it seems like you either need to run SN95 length control arms or use shorter tie rods with the Fox arms.
You need the right steering column link, the HV power steering pump, and the tie rods. Bump steer correction kit.
Everyone talks about what is different, and custom, but rack and pinion suppliers know what is the same. As long as you find the right tie rods, you can modify the track widths to suit common parts.
The Cobra powered rack and pinion steering is based on the 20 and 15:1 power steering unit used since 1968 by Adwest in the United Kigngdon, and its difference between the earlier ones is its rack width, clamping, and its torsion bar diameter.
General info:-
The better Rack and pinion systems have the stiff, 0.210" torsion bar with a ratio similar to the 15:1 ratio used in later 1986 onwards Mustangs. Jaguars, IIRC, are 13.7:1, same as Cam Gears Jensen Interceptor, and FF, and Aston Martin, 2.57 turns to 2.75 turns lock to lock.
The 15:1 Mustangs are 2.25, 2.5, or 2.75 turns lock to lock. The earlier TRW ones 20:1, and 3.1 to 3.25 depnding on ratio, turning circle lock off tanks or rack limiters. Ford basically reworked the steering lock to ensure the later wider 7"to 8" rims didn't hit the suspension parts. Earlier Fox Mustangs had at best, TRX 5.9" rims. Then in 1980, the first 8 or so production McLaren M81's had 15 x 8's and 255/55 HR 15's, but it's width was all done with stock parts because the extension was all on the outside the stock. The wheel offset did it all, and the front and rear tracks were 59.6 and 60", up three inches from the stock 56.6 and 57".
The later Fox 4's and New Edge SN95's went right up to that track width by extending the SRA, IRS and IFS hard pointsoutwards like what was first done in the 1982-1992 Linclons and 1984-1986 SVO's.
The racks themselves were made in the designs infancy by Cam Gears, but were Adwest patents, and even Adwest purchased Burman in 1978, and all that Burman/Cam Gears/StanPart/ Marles/Bendix/ TRW/ Ford brand was just typical white box supplier stuff, so the major French, German and US owned steering companies used the components, and bought the designs or owned the patents. So that's why ZF Germany made Jag, deTomaso and Maserati steering rack with Adwest patents and Cam Gears designs.
Look at any good Pommy Grand Tourer, like the Jag XJ-6, XJ-S, XJ-40, or Aston Martin, Jensen interceptor , or Italian Maserati or power steered Mustang II or Chevrolet Chevette, and you've got the same generic kind of rack and pinion system. They all run Jaguar style torsion bars, 0.190, 0.210, 0.235, 0.250".
As the bar daimeter goes up, the feedback Nemitz diagram relationship changes, and you get more steering "weight". The Feel of the steering is controlled by bump steering curve, the solitidy of the steering box mounting, the steering damper compliance if its rubber or solid. Playing with the rate of power assitancedoesn't add road feel. Some tires tram line, and Ford basically, like the IRS, decided to opt out of 100% solid mounting due to customer complaint regards impact harshness over cement filler joints and Michigan style pot hole "crash through".
Note:-
The best of the last SN95 Mustangs, used 15:1 internal gears, and the same kind of stiff torsion bar the XJR Walkinshaw Jags used, 0.235".
Everyone talks about what is different, and custom, but rack and pinion suppliers know what is the same. As long as you find the right tie rods, you can modify the track widths to suit common parts.
The Cobra powered rack and pinion steering is based on the 20 and 15:1 power steering unit used since 1968 by Adwest in the United Kigngdon, and its difference between the earlier ones is its rack width, clamping, and its torsion bar diameter.
General info:-
The better Rack and pinion systems have the stiff, 0.210" torsion bar with a ratio similar to the 15:1 ratio used in later 1986 onwards Mustangs. Jaguars, IIRC, are 13.7:1, same as Cam Gears Jensen Interceptor, and FF, and Aston Martin, 2.57 turns to 2.75 turns lock to lock.
The 15:1 Mustangs are 2.25, 2.5, or 2.75 turns lock to lock. The earlier TRW ones 20:1, and 3.1 to 3.25 depnding on ratio, turning circle lock off tanks or rack limiters. Ford basically reworked the steering lock to ensure the later wider 7"to 8" rims didn't hit the suspension parts. Earlier Fox Mustangs had at best, TRX 5.9" rims. Then in 1980, the first 8 or so production McLaren M81's had 15 x 8's and 255/55 HR 15's, but it's width was all done with stock parts because the extension was all on the outside the stock. The wheel offset did it all, and the front and rear tracks were 59.6 and 60", up three inches from the stock 56.6 and 57".
The later Fox 4's and New Edge SN95's went right up to that track width by extending the SRA, IRS and IFS hard pointsoutwards like what was first done in the 1982-1992 Linclons and 1984-1986 SVO's.
The racks themselves were made in the designs infancy by Cam Gears, but were Adwest patents, and even Adwest purchased Burman in 1978, and all that Burman/Cam Gears/StanPart/ Marles/Bendix/ TRW/ Ford brand was just typical white box supplier stuff, so the major French, German and US owned steering companies used the components, and bought the designs or owned the patents. So that's why ZF Germany made Jag, deTomaso and Maserati steering rack with Adwest patents and Cam Gears designs.
Look at any good Pommy Grand Tourer, like the Jag XJ-6, XJ-S, XJ-40, or Aston Martin, Jensen interceptor , or Italian Maserati or power steered Mustang II or Chevrolet Chevette, and you've got the same generic kind of rack and pinion system. They all run Jaguar style torsion bars, 0.190, 0.210, 0.235, 0.250".
As the bar daimeter goes up, the feedback Nemitz diagram relationship changes, and you get more steering "weight". The Feel of the steering is controlled by bump steering curve, the solitidy of the steering box mounting, the steering damper compliance if its rubber or solid. Playing with the rate of power assitancedoesn't add road feel. Some tires tram line, and Ford basically, like the IRS, decided to opt out of 100% solid mounting due to customer complaint regards impact harshness over cement filler joints and Michigan style pot hole "crash through".
Note:-
The best of the last SN95 Mustangs, used 15:1 internal gears, and the same kind of stiff torsion bar the XJR Walkinshaw Jags used, 0.235".
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Help me here Dean, does all that mean, ‘Yes’?
Is there a vast improvement from getting a brand new track like from Flaming River?
Without going absolutely crazy throwing money at Booger, I would like to get the best I can for the money. I want a nice front end that will keep up with the back. If that makes sense to y’all.
I think it was, you know what Noobz? If I just used that little search thing I could probably have figured it out. I’m an r-tard.
The Cobra steering rack is exceptionally good. Worth everything you can throw at to get it.
Fit the Cobra rack, and do the modifications to make it fit.
1.Post 1986 power steering pump, its bigger and won't run out of assistance when your turning hard on an off lock.
2. the steering column to rack link, (SN95's have a differnt steering column with air bag and a longer distance from the K member to the pedals. The Fox needs a specails rag joint,and a solid one is better if its legal in your state.
3. the tie rods, ( the rack dimensions differ, so you gotta find the Tie Rods Jack H recommends)
4. the bump steer kit is what I'd look at. The mounts differ. Jack can help you with that. Jack H is not trying to soley sell stuff...he know exactly what is required to make an 83 handle and point well within a budget.
The K member your using should have the corrections for the Ackerman that Ford goffed on in 1978 with short wheel base Mustangs. Ackerman is the splay angle on turns. It makes radial cars point properly at low and high speed, and is different to the static toe in settings. Any time wheel base changes, Ackermnan should too. Ford snipped 5-1/8" off the Fox frame for the Stang, but just left the K member the same as the long wheel base Foxes, and didn't fix it untill 1982 on the Lincolns, and 1984 on the SVO, and then 1986 on the Mustangs and Capris. It scrapes and shimmies on hard turns because of it,and its very sensitive to tramlining.
Ford at Detriot got it all right back in 1978 when the Fox car was productionised. The Ackerman was a minror issue. They already had 10 years of development work with Rack and pinion systems from Ford's Escort, Capri, all the deTomaso's, and the 1979-1981 Right Hnad Drive British Mustangs had Jaguar power Rack and Pinion steering systems.
So with all this stuff, Your just improving on your car by adding 26 years of updated parts, which wer already very good from Job One.
It'll point brillaintly with those four mods. The basic steering is okay, but the Cobra steering has a mass produced rack with subtle changes in the way it was machined and its the honey pot of all Ford R&P systems.
IMHO, The biggest cost saving will be hard mounting your IRS, and looking at mini tubbing the rear chassis rails. That alone will ensure you won't suffer the wipeout most 351 W owners suffer.
The right tire combination with a proper IRS, your doing everything Alessandro deTomaso was doing on his big 351 Cleveland powered Deuville drived hybrids from 1969 to 1989.
Same steering, same kind of IRS philosphy, same big inch 4 by 3.5 stroke 351 up front. Same Ghia derived notch styling.
Fit the Cobra rack, and do the modifications to make it fit.
1.Post 1986 power steering pump, its bigger and won't run out of assistance when your turning hard on an off lock.
2. the steering column to rack link, (SN95's have a differnt steering column with air bag and a longer distance from the K member to the pedals. The Fox needs a specails rag joint,and a solid one is better if its legal in your state.
3. the tie rods, ( the rack dimensions differ, so you gotta find the Tie Rods Jack H recommends)
4. the bump steer kit is what I'd look at. The mounts differ. Jack can help you with that. Jack H is not trying to soley sell stuff...he know exactly what is required to make an 83 handle and point well within a budget.
The K member your using should have the corrections for the Ackerman that Ford goffed on in 1978 with short wheel base Mustangs. Ackerman is the splay angle on turns. It makes radial cars point properly at low and high speed, and is different to the static toe in settings. Any time wheel base changes, Ackermnan should too. Ford snipped 5-1/8" off the Fox frame for the Stang, but just left the K member the same as the long wheel base Foxes, and didn't fix it untill 1982 on the Lincolns, and 1984 on the SVO, and then 1986 on the Mustangs and Capris. It scrapes and shimmies on hard turns because of it,and its very sensitive to tramlining.
Ford at Detriot got it all right back in 1978 when the Fox car was productionised. The Ackerman was a minror issue. They already had 10 years of development work with Rack and pinion systems from Ford's Escort, Capri, all the deTomaso's, and the 1979-1981 Right Hnad Drive British Mustangs had Jaguar power Rack and Pinion steering systems.
So with all this stuff, Your just improving on your car by adding 26 years of updated parts, which wer already very good from Job One.
It'll point brillaintly with those four mods. The basic steering is okay, but the Cobra steering has a mass produced rack with subtle changes in the way it was machined and its the honey pot of all Ford R&P systems.
IMHO, The biggest cost saving will be hard mounting your IRS, and looking at mini tubbing the rear chassis rails. That alone will ensure you won't suffer the wipeout most 351 W owners suffer.
The right tire combination with a proper IRS, your doing everything Alessandro deTomaso was doing on his big 351 Cleveland powered Deuville drived hybrids from 1969 to 1989.
Same steering, same kind of IRS philosphy, same big inch 4 by 3.5 stroke 351 up front. Same Ghia derived notch styling.
Yeah. I did it. Was easy....easier that that rear your about to put in.
Rack, hybrid shaft and then I chose to swap the inners to fox inners and run fox outers. You can also just run 1990 Taurus outer tie rod ends. Bumpsteer kit all depends on actual ride height.
But feels much better than the stock rack ever did. Not a night and day difference, but no more over assisted bus type steering. Feels modern
Since Dave spent some bennies getting a ground on rear end, I don't feel too bad about jumping in and hi jacking this beotch for a minute.
I've searched before but have never found any other answer...but is there any 'easier' way of getting rid of the over assisted steering, other than finding an authentic cobra rack? I'm almost 50 so I would like a little assist, but if I think about turning, the car turns.
I've searched before but have never found any other answer...but is there any 'easier' way of getting rid of the over assisted steering, other than finding an authentic cobra rack? I'm almost 50 so I would like a little assist, but if I think about turning, the car turns.
droopie85gt and Davedacarpainter
95% of drivers really wouldn't know or be able to sense any major differences, but Power Steering is probably the most complicated feedback system man kind has devised.
When I was younger, I loved my 1984 Falcons variable ratio Bishops Kirby power steering, and hated the same Mustang steering gear in my V6 1982 Cortina. When I got the 81 Mustang I6, I loved its light steering. The Falcon had 2.6 turns lock to lock, the Cortina and Mustang, 3.2 turns. The Fox was light years ahead
It all ponders the eternal question Dave asked ...is a Flaming River rack better than Fords own? Well the fact that you kind cannot get a brand spanking new Cobra replacement except used or from NOS might mean a Flamming River rack is your only option if you have to get a good replacment one fast.
Aftermarket hard parts generally don't have Fords quality control. Although excellent, any thing made in yearly batches of less than 500 units won't have the Ford Motor Companies Process Control. So for steering, IRS units, tie rod ends, try to use Fords recomended standard parts. Or the Ford approved OEM replacements. The Hybrid parts are unique, and designed to get odd ball combinations from diverse years to work, so you have to trust the Quality Control and Assurance is up to spec by buying from a non Ford supplier you trust.
The big Three (Ford, GM and Mopar) still find that a smooth, Noise Vibration and Harshness free drive train is what 95 % of customers want, so some parts aren't what Ford would have used. The matter of suspension and steering compliance bushing is traded off against how rigid the chasis is. The basic 2003 Cobra steering rack is the culmination of 35 years of Rack and Pinion steering development, but even the 2003 Cobra chasis was only marginal for stiffness, so there was no way Ford was gonna put hard as Hades bushes on a 300 plus horsepower car which might end up being driven HARD.
In Australia, General Motors Holden subsidary even put a Bishops variable ratio pinion gear in the same steering box. Most rack and pinions are based on the US TRW patents which came from Adwest of Great Britain. The variable ratio was great for IRS vehicles, to take the sharpness out of the steering off center , but in the cars that use it (the Holden Commodore) its not as good as any of Fords Mustang steering rack placement. Jack Roush and Dearborn did a crap load of development in the SVT years.
In 1978, Ford USA really went to a lot of trouble making the stock Fox steering gear great. By 2003, the Cobra rack machining gave a constant, communicative feel to the driver. All Foxes have front mounted steering gear which is a lot safer as it accentualtes the understeer. Aussie Fords and Commodores had rear mounted steering boxes, and they make roll oversteer happen. So the Fox frame starts with a free extra base, 25% of the chassis was sorted by Fords steering box placement. Ford copied the best industry practice, and made a great choice in 1978.
droopie85gt
The rack bushing and SPR process the steering was contructed with define most of the steering feel. The SPR process is how the rack is machined, and no one did it better than Fords suppliersunder million dollar contract. Even if you hand built one rack, it probalby wouldn't be as good as Fords Sausage Machine rack. Its to do with the roughness RA value of the valves, the cut of the rack, and how its cutting tools are controlled and and changed over the production run.
Drew, steering weight is not feel, but you can create an artificial fell thats good enough for most of us. You do it by sharpning up the steerring ratio from 20:1 to 15 or 13.7:1, and adding some weight by fitting bigger tires, and dialing in as much castor as you can, and on early Foxes, that might mean notching the front gaurd to fit the forward movement of the racked forwards wheels. Ford did it all by 1991 on the V8 Fox Mustangs.
Compared to the same steering rack on the British and Aussie Cortinas (very light and awfull power steering that was very lifeless),
the Australian Commodores (very heavy, very communicative, but prone to roll over steer due to the steering rack placment)
and some of the Falcons (all rack and pinion Falcons were rear mounted racks, and they are very sensitive, and also roll over steer)
Even the stock early 1979-1983 ish Fox Mustang rack with all its bad Ackerman and its lifeless 20:1 steering ratio and small power steering pump, the whole car requires just a delicate touch, and really works well with better tires. Its stil a direct steering system, and I loved mine. Steeping into a Commodore, or Falcon, or the S197's I used to unload from the container port....the later powered rack ratios are far sharper, and there is real weight, and real steering feel. A "is this realy power steering?" feeling.
Anything that reduced turns lock to lock will add weight
Most of us have torn shoulders and that kind of steering feel would upset a lot of customers in the US if every Mustang had it.
So in summary, your better off with a later fast ratio rack, a later high Volume steering pump, and adding some caster, some extra tire width, and dealing with the Ackerman issue if your doing a lot of parking. Rack limiters are a got idea, so are wheel spacers.
To use the Cobra rack takes a lot of extra work, but its all worth it.
The problem is expense. To change to a factory Ford rack that is in good shape requires a lot of time and expense.
95% of drivers really wouldn't know or be able to sense any major differences, but Power Steering is probably the most complicated feedback system man kind has devised.
When I was younger, I loved my 1984 Falcons variable ratio Bishops Kirby power steering, and hated the same Mustang steering gear in my V6 1982 Cortina. When I got the 81 Mustang I6, I loved its light steering. The Falcon had 2.6 turns lock to lock, the Cortina and Mustang, 3.2 turns. The Fox was light years ahead
It all ponders the eternal question Dave asked ...is a Flaming River rack better than Fords own? Well the fact that you kind cannot get a brand spanking new Cobra replacement except used or from NOS might mean a Flamming River rack is your only option if you have to get a good replacment one fast.
Aftermarket hard parts generally don't have Fords quality control. Although excellent, any thing made in yearly batches of less than 500 units won't have the Ford Motor Companies Process Control. So for steering, IRS units, tie rod ends, try to use Fords recomended standard parts. Or the Ford approved OEM replacements. The Hybrid parts are unique, and designed to get odd ball combinations from diverse years to work, so you have to trust the Quality Control and Assurance is up to spec by buying from a non Ford supplier you trust.
The big Three (Ford, GM and Mopar) still find that a smooth, Noise Vibration and Harshness free drive train is what 95 % of customers want, so some parts aren't what Ford would have used. The matter of suspension and steering compliance bushing is traded off against how rigid the chasis is. The basic 2003 Cobra steering rack is the culmination of 35 years of Rack and Pinion steering development, but even the 2003 Cobra chasis was only marginal for stiffness, so there was no way Ford was gonna put hard as Hades bushes on a 300 plus horsepower car which might end up being driven HARD.
In Australia, General Motors Holden subsidary even put a Bishops variable ratio pinion gear in the same steering box. Most rack and pinions are based on the US TRW patents which came from Adwest of Great Britain. The variable ratio was great for IRS vehicles, to take the sharpness out of the steering off center , but in the cars that use it (the Holden Commodore) its not as good as any of Fords Mustang steering rack placement. Jack Roush and Dearborn did a crap load of development in the SVT years.
In 1978, Ford USA really went to a lot of trouble making the stock Fox steering gear great. By 2003, the Cobra rack machining gave a constant, communicative feel to the driver. All Foxes have front mounted steering gear which is a lot safer as it accentualtes the understeer. Aussie Fords and Commodores had rear mounted steering boxes, and they make roll oversteer happen. So the Fox frame starts with a free extra base, 25% of the chassis was sorted by Fords steering box placement. Ford copied the best industry practice, and made a great choice in 1978.
droopie85gt
The rack bushing and SPR process the steering was contructed with define most of the steering feel. The SPR process is how the rack is machined, and no one did it better than Fords suppliersunder million dollar contract. Even if you hand built one rack, it probalby wouldn't be as good as Fords Sausage Machine rack. Its to do with the roughness RA value of the valves, the cut of the rack, and how its cutting tools are controlled and and changed over the production run.
Drew, steering weight is not feel, but you can create an artificial fell thats good enough for most of us. You do it by sharpning up the steerring ratio from 20:1 to 15 or 13.7:1, and adding some weight by fitting bigger tires, and dialing in as much castor as you can, and on early Foxes, that might mean notching the front gaurd to fit the forward movement of the racked forwards wheels. Ford did it all by 1991 on the V8 Fox Mustangs.
Compared to the same steering rack on the British and Aussie Cortinas (very light and awfull power steering that was very lifeless),
the Australian Commodores (very heavy, very communicative, but prone to roll over steer due to the steering rack placment)
and some of the Falcons (all rack and pinion Falcons were rear mounted racks, and they are very sensitive, and also roll over steer)
Even the stock early 1979-1983 ish Fox Mustang rack with all its bad Ackerman and its lifeless 20:1 steering ratio and small power steering pump, the whole car requires just a delicate touch, and really works well with better tires. Its stil a direct steering system, and I loved mine. Steeping into a Commodore, or Falcon, or the S197's I used to unload from the container port....the later powered rack ratios are far sharper, and there is real weight, and real steering feel. A "is this realy power steering?" feeling.
Anything that reduced turns lock to lock will add weight
Most of us have torn shoulders and that kind of steering feel would upset a lot of customers in the US if every Mustang had it.
So in summary, your better off with a later fast ratio rack, a later high Volume steering pump, and adding some caster, some extra tire width, and dealing with the Ackerman issue if your doing a lot of parking. Rack limiters are a got idea, so are wheel spacers.
To use the Cobra rack takes a lot of extra work, but its all worth it.
The problem is expense. To change to a factory Ford rack that is in good shape requires a lot of time and expense.
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