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post #1 of 22 Old 12-11-2010, 04:09 PM Thread Starter
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Griggs kmember with MM A-arms

I know that some people have done this combination, and I was wondering how well does it work? Do Griggs, and MM kmembers mount the wheels in the same location if they use the same offsets on the a-arms?

The reason I don't want to run a MM kmember is it requires you to run a oil filter relocation kit if your Modular car comes factory with a oil cooler. I don't like that, and the Griggs kmember doesn't make you do that. By the same token I don't want to pay for Griggs a-arms because they are expensive, and they don't look overly street friendly.

Also if you use MM new negative offset a-arms that mount the wheels in the stock locations does that mean that the frontend will not see an kind of difference in its geometry? I'm curious about this as I was wanting to run a Steeda 5 Link II, but have read that it works better than the torque arm setups from griggs/MM with the stock frontend geometry, but that the torque arm setups work better with the improved geometry of the MM/Griggs front suspensions. I'm doing a Modular swap so the stock kmember isn't an option.(modding a factory Modular kmember to work in a foxbody moves the motor way forward among other things, and I don't like that idea) I'm not so against running a torque arm setup, but I would prefer to go with the Steeda 5 Link II if it would work properly with my front suspension.

Does the Griggs torque arm require exhaust modification like the MM one does? Aren't they mounted differently?

Thanks for any help,

Jesse

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post #2 of 22 Old 12-12-2010, 11:49 AM
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I would be very careful about mixing and matching parts between MM and Griggs. The two systems are designed around different roll centers. I am actually in the process of collecting MM parts so that I can take my Griggs TA/PHB setup off. The exhaust clearance is awful with the Griggs parts. The TA uses a straight crossmember that doesnt' give the X or H-pipe anywhere to go but down...right in the center of the car where the ground clearance is needed the most. Also the way the PHB mounts to the frame makes it a nightmare for tailpipe clearance on the driver's side. I'll have to be sure to take lots of pictures of the before and after when I do my R&R. I am utterly confident that the MM pieces are going to be MUCH more street car friendly.

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post #3 of 22 Old 12-12-2010, 02:22 PM Thread Starter
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^ Good info.

My plan was to use a MM panhard bar even if I went with a Griggs torque arm. I just really don't want to cut up my Prochamber to run a MM torque arm, but there no way I'm going to run a stock 4 link again, or any kind of 4 link for that matter with the uppers in there stock location. The Foxbody Mustangs 4 link is the biggest POS rear suspension in the world. I've also decided not to swap in the IRS from my Cobra either.

I would love to keep the factory roll center with a MM or Griggs kmember, and run a 5 link.
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post #4 of 22 Old 12-15-2010, 03:37 PM
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Quote:
Originally Posted by JROC View Post
I know that some people have done this combination, and I was wondering how well does it work? Do Griggs, and MM kmembers mount the wheels in the same location if they use the same offsets on the a-arms?
Yes.

Quote:
I don't want to pay for Griggs a-arms because they are expensive, and they don't look overly street friendly.
The girggs arms are FINE on the street and for track usage too.

I haven't seen their current design, but I seem to remember griggs adding a cross tube just like the MM design because too many folks were saying the design without the arm didn't look strong enough.

Whether that cross tube adds significant strength or not is academic. The arms are more than up to street use. Thousands of Mustangs have been using them for a long time and personally I know of only two failures and these were on road-raced cars.

Quote:
Also if you use MM new negative offset a-arms that mount the wheels in the stock locations does that mean that the frontend will not see an kind of difference in its geometry?
Depends on what geometry you are talking about. The offset of the A-arm simple determines where in the wheel well the wheel/tire ends up. the forward offset arm moves the wheel/tire forward 0.75", that is all.

Other aspects of the front suspension's geometry (track width, roll center location, Ackerman, etc...) are mostly unaffected buy A-arm offset.

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I'm curious about this as I was wanting to run a Steeda 5 Link II, but have read that it works better than the torque arm setups from griggs/MM with the stock frontend geometry, but that the torque arm setups work better with the improved geometry of the MM/Griggs front suspensions.
What does "works better" mean? I can only assume it means the car is more balanced and doesn't understeer as much compared to a TA/PHB setup. (If that's not the case, ignore the next two paragraphs.)

This is actually a problem. The car is more balanced because the rear doesn't have as much grip as it would with a TA/PHB setup. The solution here is not to reduce rear grip levels (that would be like putting a restrictor on your engine to keep from spinning your tires at the drag strip!)

Instead, the solution is to increase the front grip to match the grip levels of the rear end.


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I'm doing a Modular swap so the stock kmember isn't an option.(modding a factory Modular kmember to work in a foxbody moves the motor way forward among other things, and I don't like that idea) I'm not so against running a torque arm setup, but I would prefer to go with the Steeda 5 Link II if it would work properly with my front suspension.
OK -- I'm confused

First you say that the Steeda rear setup works better with the factory front K-member.

Then you say that you don't want to run a factory K-member because of the modular swap.

Then you say you WANT to run the Steeda setup.

WTF?!?

Quote:
Does the Griggs torque arm require exhaust modification like the MM one does? Aren't they mounted differently?
Depends on the exhaust setup, I would think. My griggs K-member works fine with both shorty and most common longtube headers, though I'm sure there's an oddball setup out there some where that might not fit.

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post #5 of 22 Old 12-15-2010, 03:41 PM
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Quote:
Originally Posted by JROC View Post
My plan was to use a MM panhard bar even if I went with a Griggs torque arm.
Nothing wrong with that.

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I would love to keep the factory roll center with a MM or Griggs k-member, and run a 5 link.
Good Lord WHY?!? you'd have to do a LOT of re-engineering to restore the factory's crappy roll center.

I just don't understand why you're so enamored with the Steeda rear setup. It's a 4-link with parallel upper arms and a Panhard Bar. It doesn't buy you anything that you don't get with a TA or 3-link setup.

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post #6 of 22 Old 12-15-2010, 05:49 PM Thread Starter
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^ Thanks for the reply's.

The reason I don't what to run a factory Modular kmember in a 5.0 car is because it has to be modded to fit, and when you do get it to work it moves the motor several inch forward to where its suppose to be located. Aftermarket kmembers built for this swap move the motor back to it ideal location.

Reasons I'm liking the 5 link II is because its simpler. No modding my midpipe, no real ground clearance issues, less weight is nice, no brake hop. Rear C/O's are not an option for me as I don't think they are going to fit with the 315's on 10.5" wheels that are on the back of my car.

From what I've been studying on here, and elsewhere is that the 5 link is designed to work best with the factory geometry, and that a torque arm will cause it to push. Also my roller has a D&D kmember/a-arms on it know with 17x8's wearing 255's now, and its rubbing the front of the fenders really bad when you turn the wheels so getting some decent sized tire to fit is already going to be tough.

Right now I'm thinking I'm going to run a torque arm setup as I don't want to compromise performance because I like this rear end as oppose to that rear end, but I was just wondering if there was a way to make the 5 Link work ideally with a Griggs/MM frontend.
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post #7 of 22 Old 12-16-2010, 02:04 PM
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Originally Posted by JROC View Post
Reasons I'm liking the 5 link II is because its simpler.
Not really. You can't get much simpler than a torque-arm (7 articulated joints), followed closely by a 3-link (8 articulated joints.) The 5-link is arguably the most complex with 10 articulated joints.

Quote:
No modding my midpipe,
Is your mid-pipe significantly different from the stock setup? Both the Griggs and MM torque arms work with factory exhaust setups with no modifications.

Quote:
no real ground clearance issues,
That's an old myth. The lowest portion of the torque arm is below and an inch or two in front of the axle's centerline. When driving over speedbumps, or dirving up driveways or trailers, the tires to a fine job of keeping the torque arm above any obstacles. The only time the TA might cause a groudn clearance issue is if you're taking the car offroad, OR if the road you're driving os so rutted it ends up with a 4" high crown between the tire ruts (and then, that's pretty much into off-roading category.)

In the years I drove my TA-equipped '88, I never scraped the TA on the ground, even at road-racing ride height (4" from the road surface to the rocker panels.)

Quote:
no brake hop
TA's have been known to contribute to brake hop (my setup does not.) If you end up with rear brake hop, you tune it our the same as with any other rear setup. (And 5-links can brake hop too.)

Quote:
From what I've been studying on here, and elsewhere is that the 5 link is designed to work best with the factory geometry, and that a torque arm will cause it to push.
Of course. That's because the 5-link doesn't give you as much rear grip as a TA setup does , everything else being equal.

Push/loose is a matter of BALANCE. You can have a car that's well balanced, where both ends lose grip at the same time, but will still have a fairly level of grip. And you can have a car that's horribly out of balance and pushes like there's no tomorrow and the te car that pushes can still be much faster because while its out of balance, it;s levels of grip are still much higher than the well-balanced car.

Quote:
Also my roller has a D&D kmember/a-arms on it know with 17x8's wearing 255's now, and its rubbing the front of the fenders really bad when you turn the wheels so getting some decent sized tire to fit is already going to be tough.
That wheel/tire combo is pretty popular and not known to cause rubbing issues, regardless of the front suspension setup. (I ran that combo for a LONG time with the factory setup. If yours rubs I'd look at the K-member and A-arms to make sure the spindle is located in more or less the same place as with the factory setup. I'd also make sure I'm running the right SN95 spindle (see the MM web site's tech articles,) and that the wheel offset is correct.

Quote:
Right now I'm thinking I'm going to run a torque arm setup as I don't want to compromise performance because I like this rear end as oppose to that rear end, but I was just wondering if there was a way to make the 5 Link work ideally with a Griggs/MM frontend.
Two things to duplicate: the roll center and the anti-squat percentage, with the roll center being the most important. I'd also look into the 5-link's roll-steer characteristics, if any.

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post #8 of 22 Old 12-16-2010, 05:52 PM Thread Starter
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^ Thanks for all your help.

I'm thinking I'm probably going to opt for a torque setup, as it probably is just the best way to go with the Griggs/MM frontend.

How well does the Griggs kmember/MM A-arm combo work?
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post #9 of 22 Old 12-17-2010, 10:19 AM
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Originally Posted by JROC View Post
How well does the Griggs kmember/MM A-arm combo work?
Pretty well. I've been running it for a few years now. I went that route because I wanted SN95-length arms (I initially had the shorter Fox arms,) for the extra track width, plus I wanted what I thought was the stronger MM arm. After talking to folks who are better mechanical engineers than I am (I was working for Lockheed Martin at the time,) I found out the Griggs tubular arms are pretty much as strong as the MM arms without the extra tubing. (Griggs has since re-designed their tubular arms with that extra tubing to make them look stronger to the uneducated.)

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post #10 of 22 Old 12-17-2010, 09:07 PM
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The Pro Chamber will definitely need some clearancing to work with the Griggs TA.

Anybody have any aftermarket cat backs they know fit with the Griggs TA/PHB? Haven't called Griggs about it yet, but IIRC when I bought that stuff they liked the Flowmaster tailpipes for LXs.

In the market...

Quote:
Originally Posted by gt40mkII View Post
That's an old myth. The lowest portion of the torque arm is below and an inch or two in front of the axle's centerline. When driving over speedbumps, or dirving up driveways or trailers, the tires to a fine job of keeping the torque arm above any obstacles. The only time the TA might cause a groudn clearance issue is if you're taking the car offroad, OR if the road you're driving os so rutted it ends up with a 4" high crown between the tire ruts (and then, that's pretty much into off-roading category.)
My Griggs SD TA has scrapes in that spot. Never been offroading with it either.

Appreciate your MM SN95 control arm comments, I have a set laying around I pulled off my SVO to sell it and have been wondering if I should put them on my coupe. Are yours the offset ones?


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Last edited by luvtolean; 12-17-2010 at 09:12 PM.
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post #11 of 22 Old 12-20-2010, 05:47 PM
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Originally Posted by luvtolean View Post
My Griggs SD TA has scrapes in that spot. Never been offroading with it either.
Under the diff? You should have about 4"-6" inches of clearance there, depending on tire diameter, which should be plenty to keep that off the ground.


Quote:
Appreciate your MM SN95 control arm comments, I have a set laying around I pulled off my SVO to sell it and have been wondering if I should put them on my coupe. Are yours the offset ones?
You mean forward-offset? No. Mine are factory offset. They're dimensionally identical to factory SN95 arms.

(The Griggs K-member pulls the a-arms forward 0.75", which effectively pulls the wheel/tire forward 0.75", which is more than enough to seriously screw with fender clearance running 255 17" tires.)

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post #12 of 22 Old 12-20-2010, 06:22 PM
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I doubt it would be hard to run rear exit tail pipes with the PHB. Granted it may take a little cutting and welding, but we were able to do so with my watts link years ago.

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post #13 of 22 Old 12-20-2010, 09:22 PM
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Originally Posted by gt40mkII View Post
Under the diff? You should have about 4"-6" inches of clearance there, depending on tire diameter, which should be plenty to keep that off the ground.
Yep. Car is on jackstands now so I can't measure it but I can tell you for sure it has hit the ground several times, surprised me too. Not much you can do on installation to screw that up and obviously ride height doesn't really matter. It's not getting aggressive with it on track or anything either, still only been driven on the street.

I'm not really arguing against them or anything, but IME they can rub. Still wouldn't give it up though!

Quote:
You mean forward-offset? No. Mine are factory offset. They're dimensionally identical to factory SN95 arms.

(The Griggs K-member pulls the a-arms forward 0.75", which effectively pulls the wheel/tire forward 0.75", which is more than enough to seriously screw with fender clearance running 255 17" tires.)
Right, OK. I still have the stock K-member, was just wondering with the wheel pushed out how bad it might get. Sounds like there's no reason not to try it though.

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Originally Posted by Stevecooper View Post
I doubt it would be hard to run rear exit tail pipes with the PHB. Granted it may take a little cutting and welding, but we were able to do so with my watts link years ago.
You should talk to your tire vendor, they forgot the tread.

I have a Fox so it might not translate, but which brand are those?

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post #14 of 22 Old 12-21-2010, 12:51 PM
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Quote:
Originally Posted by luvtolean View Post
The Pro Chamber will definitely need some clearancing to work with the Griggs TA.

Anybody have any aftermarket cat backs they know fit with the Griggs TA/PHB? Haven't called Griggs about it yet, but IIRC when I bought that stuff they liked the Flowmaster tailpipes for LXs.

In the market...



My Griggs SD TA has scrapes in that spot. Never been offroading with it either.

Appreciate your MM SN95 control arm comments, I have a set laying around I pulled off my SVO to sell it and have been wondering if I should put them on my coupe. Are yours the offset ones?
I have MAC longtubes and MAC prochamber with Griggs SD TA and had no issues at all with them interferring with each other. My exhaust is dumped under the car so I didn't have to deal with PHB/tailpipe issues if there would have been any, but the TA/prochamber worked fine together for me.

As far as the TA scraping on things, there are a couple of little scratches on it so I know at one time or another it has come in contact with the ground, but I've driven this car all over the place with this set up, for years, and it looks like it's only made contact with something a couple of times. The prochamber and/or my mufflers scrape things quite often but it's only a couple of inches off the ground with as low as my car sits.







As you can see it's pretty low to the ground.






The only issue I had with Griggs stuff was the upper arm of the SLA making contact with the bleeded bolt thing on my Cobra brakes, which I was told would happen. Shaved the bolt down some and eliminated the problem. Everthing else installed with no problems at all.


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post #15 of 22 Old 12-21-2010, 02:45 PM
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Is that the Dragon?

My Pro Chamber had those scratches too.

I guess I should've said a Fox with a Pro Chamber and shorties will interfere. I had to get the torch out and clearance it.

It all bolts up, but it will rattle driving down the road due to contact.

Just sold mine to go back to running cats so I can't take a pic unfortunately.

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post #16 of 22 Old 12-21-2010, 05:03 PM Thread Starter
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Thanks for all the info guys. It is good stuff.
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post #17 of 22 Old 12-21-2010, 11:43 PM
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Quote:
Originally Posted by JROC View Post
^ Good info.

My plan was to use a MM panhard bar even if I went with a Griggs torque arm. I just really don't want to cut up my Prochamber to run a MM torque arm, but there no way I'm going to run a stock 4 link again, or any kind of 4 link for that matter with the uppers in there stock location. The Foxbody Mustangs 4 link is the biggest POS rear suspension in the world. I've also decided not to swap in the IRS from my Cobra either.

I would love to keep the factory roll center with a MM or Griggs kmember, and run a 5 link.
Yeah that's really a good info. I am definitely agree.
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post #18 of 22 Old 12-22-2010, 02:24 AM
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Wow your driveshaft is super close to the bolt for the chassis mount of the TA!
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post #19 of 22 Old 12-22-2010, 07:06 PM
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Originally Posted by Apocolipse View Post
Wow your driveshaft is super close to the bolt for the chassis mount of the TA!
I guess you're talking about my picks above. Yes you are right, but it is only like that when the car is on jack stands and the rear wheels are at full droop. When at normal ride height they aren't close at all.

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post #20 of 22 Old 12-22-2010, 07:07 PM
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Is that the Dragon?
Yep

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post #21 of 22 Old 12-22-2010, 08:32 PM
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Nice.

No state income tax and great roads. One of these days we're going to get smart and move out there.

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post #22 of 22 Old 01-13-2011, 10:58 AM
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Originally Posted by Ken03KBGTvert View Post
I guess you're talking about my picks above. Yes you are right, but it is only like that when the car is on jack stands and the rear wheels are at full droop. When at normal ride height they aren't close at all.
If that's too close for comfort, you can cut the upper bushing .25" (make sure to cut the center sleeve the same amount) to allow for alittle more room at full droop.


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Originally Posted by Stevecooper View Post
I doubt it would be hard to run rear exit tail pipes with the PHB. Granted it may take a little cutting and welding, but we were able to do so with my watts link years ago.[/IMG]

That is one of the few Watts setup's that I've seen with tail pipes. Doing this might not allow you full adjustment on the watts, but for a street/OT car I don't see an issue.

Most of the major X-pipes (BBK) work without modification. Almost all of the H-pipes need the cross over moved.

Most long tube headers work, but as is inherint to all the long tubes they hang kinda low so you have to tuck them up as high as possible when installing to get the most ground clearance.

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