Why does the C4 IRS suck
Thread Starter
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From: Slidell Louisiana
Why does the C4 IRS suck
up a lot of HP?
I have been surfing the F-body boards for a few years. I have notice that mods seem to provide F-BODIES a bigger gain than on the Y-BODIES. On the A4s the only major drivetrain difference is the independent rear suspension. What really causes this difference, is it overly optimistic F-body owners?
I am just looking for the real scoop.
Mike
I have been surfing the F-body boards for a few years. I have notice that mods seem to provide F-BODIES a bigger gain than on the Y-BODIES. On the A4s the only major drivetrain difference is the independent rear suspension. What really causes this difference, is it overly optimistic F-body owners?
I am just looking for the real scoop.
Mike
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From: Athens AL
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Solid axles in the F-body and Mustang crowd puts down power better, its a simple geometry and inertia problem. Less twisting or flexing if your axle is one solid piece.
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Originally Posted by vader86
Solid axles in the F-body and Mustang crowd puts down power better, its a simple geometry and inertia problem. Less twisting or flexing if your axle is one solid piece.
This can be minimized somewhat with the proper tweaking in set-up and geometry though. Check with the folks in the drag race section, they ought to have some good ideas. Beam plates will help, modified camber brackets, shocks, etc.
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St. Jude Donor '04-'05-'06-'07
Very true, no suspension can can do it's job unless the frame is ridgid, even the C4 can benefit from improvements there. When I first put my current engine package together, traction on street tires was a joke. I couldn't even enjoy the car w/o installing the DRs. Since then, DRM camber brackets, R-Ds Cross Frame have helped a bunch. The Cross Bar has to help too but it was already in place. I plan to install beam plates as soon as I get around to fabbing them. Goodyear F1 Supercars are a damn good biting street tire and I'll give them their credit as well.
Drifting
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From: Largo Florida
Originally Posted by Corvette Kid NC
Very true, no suspension can can do it's job unless the frame is ridgid, even the C4 can benefit from improvements there. When I first put my current engine package together, traction on street tires was a joke. I couldn't even enjoy the car w/o installing the DRs. Since then, DRM camber brackets, R-Ds Cross Frame have helped a bunch. The Cross Bar has to help too but it was already in place. I plan to install beam plates as soon as I get around to fabbing them. Goodyear F1 Supercars are a damn good biting street tire and I'll give them their credit as well.
Thread Starter
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From: Slidell Louisiana
Originally Posted by ericcer
I found the beam plates straighten out the 1-2 right side kick. It helped apply the power down.
Last edited by aboatguy; Aug 7, 2005 at 07:06 PM.
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Originally Posted by ericcer
I found the beam plates straighten out the 1-2 right side kick. It helped apply the power down.
Fish-tailing is impressive but does nothing for improving performance results.
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From: SCMR Rat Pack'r Charter Member..Great Bend KS
The IRS may absorb a little power, after all it does have four more U-joints. But, really, how much power does it take to flex a U-joint? 1/10 hp??
The main problem with drag launches is keeping both tires straight up and down, so the tire contact patch is even. The antiquated live axle excels at this (the only thing it does excel at, except maybe cost), whereas the IRS is best for handling and ride.
I'll take the trade-off any ol' day.
Larry
code5coupe
The main problem with drag launches is keeping both tires straight up and down, so the tire contact patch is even. The antiquated live axle excels at this (the only thing it does excel at, except maybe cost), whereas the IRS is best for handling and ride.
I'll take the trade-off any ol' day.
Larry
code5coupe
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From: Slidell Louisiana
Originally Posted by rocco16
The IRS may absorb a little power, after all it does have four more U-joints. But, really, how much power does it take to flex a U-joint? 1/10 hp??
Larry
code5coupe
Larry
code5coupe
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From: Athens AL
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Originally Posted by aboatguy
That is what my question is all about why do C4s seem to take such a big dyno hit?
inertia and geometry
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Originally Posted by vader86
inertia and geometry
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From: SCMR Rat Pack'r Charter Member..Great Bend KS
Originally Posted by aboatguy
That is what my question is all about why do C4s seem to take such a big dyno hit?
Who says that they do??
Larry
code5coupe
Melting Slicks
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From: NS
Now I'm not a drag racer but I'll take an IRS car over a solid axle anyday. There are many advantages to IRS for overall performance. Also, I'm not so sure the F-Body launches better than a C4 from what I've seen.
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From: SCMR Rat Pack'r Charter Member..Great Bend KS
Originally Posted by aboatguy
I have notice that mods seem to provide F-BODIES a bigger gain than on the Y-BODIES.
Sounds like the original question is this: will the same modification (K&N, say) gain more on an LT1 Camaro than on an LT1 Corvette?
Perhaps it will, since the Camaro is usually rated less to begin with.
That said....I can only ask another question: so what?
Larry
code5coupe
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From: Santa Teresa New Mexico
Originally Posted by rocco16
Perhaps thats because the Y-body makes more power to start with from the same engine, so the F-body has more potential...more room, so to speak...before it reaches parity with the Y-body??
Sounds like the original question is this: will the same modification (K&N, say) gain more on an LT1 Camaro than on an LT1 Corvette?
Perhaps it will, since the Camaro is usually rated less to begin with.
That said....I can only ask another question: so what?
Larry
code5coupe
Sounds like the original question is this: will the same modification (K&N, say) gain more on an LT1 Camaro than on an LT1 Corvette?
Perhaps it will, since the Camaro is usually rated less to begin with.
That said....I can only ask another question: so what?
Larry
code5coupe
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My experience has been that the C4 vettes and f-bodies with the same kind of drivetrain always dyno approximately the same in the HP department. The fact that the Vette was rated higher HP is simply marketing. The f-body engines made just as much HP, they are just placed in a heavier body. They're rated less so that the Corvette will still be the king of the hill.
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From: SE NY
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And too look at the entire drive train, that is what were the grears in the two cars that started this discussion??
Indeed my 3rd gen Camaro is about 300lbs heavier than my C4 so, with the same drive line, the C4 will launch harder..it's the physics not the IRS.
Indeed my 3rd gen Camaro is about 300lbs heavier than my C4 so, with the same drive line, the C4 will launch harder..it's the physics not the IRS.
Melting Slicks
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From: alaska
Originally Posted by Nathan Plemons
My experience has been that the C4 vettes and f-bodies with the same kind of drivetrain always dyno approximately the same in the HP department. The fact that the Vette was rated higher HP is simply marketing. The f-body engines made just as much HP, they are just placed in a heavier body. They're rated less so that the Corvette will still be the king of the hill.
marketing ploy? wow thats a new one.
so the f-body lt-1 engines are the same as the corvette lt-1 engine?
i thought the vette motors were better from the oil pan up.4 bolt mains,different crank number,different rods,different pistons,different cam,different heads and so on and so on.
so your saying the actual gm part #s for the above mentioned parts are the same betweem f-bodys and y-bodys?
got me wondering now.seriously.
an arcticle i read on the new mustang gt's stated they considered irs for it but opted for the straight axle for 2 reasons,1 being less parasitic draw from straight line acceleration and 2 (and mainly) being cost.
of all the cars ive owned over the years (im 48)ive never had one that hooks up (stock) like the vette does.the suspension just squats and hooks.
how many basically stock cars do you see picking up the front tire?(check some of mojo's shots)
it may cost a few ponies but i say add some elsewhere and enjoy the bennys of the irs.