I have a front and mid plate door car and it was suggested to me to use an engine torque limiter, when I asked why, the reply because other plate cars are using them. Is there a better reason than this? My trans is solidly mounted the the cross member so the motor can't move.

Mine is mounted the same way 60 ftn 1.38 with a 3300 lb car and no need for a limiter after 7-800 passes.So to answer your question I don't know any better reason.

Perhaps the name you are using for what I think you are refering to is misleading.

The front plate and the mid plate are excellent for transfering the torque of the engine to the chasssis.

They are weak in the back and forward motion of the engine in the chassis under rapid acceleration.

This can become a major issue should the car be involved in a crash. Something I'm familiar with.

Under hard acceleration the engine and trans as a package will be forced rearward, which may take up all the free play in the drive shaft spline, which could lead to damage and failure of the thrust washers in the housing.

You should have a device to limit the back and forth movement of the engine in the chassis.

^^^^^^^^^^^^^^^^


That's a perfect explanation.....well stated.


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I run one in my '65 GTO. Bracket bolted into the stock motor mount location and then goes to a bracket welded onto the frame rail.

I do not have one either. I have been thinking of adding one but not sure if needed.

would you need one on both sides of the car or just one

quote:

Originally posted by sprorx7:
would you need one on both sides of the car or just one

I have them on both sides, not hard to do on my chassis

One side...driver side.

One side.....pass side.






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As Stated for above reasons of forward and back movement you need both sides of the engine to have some kind of torque limiter. Also running a solid trans mount is fullish A cracked case waiting to happen. If you are running a mid plate the trans crossmember is there for vibration dampning and safety reasons. In a chassis book I read at one time they found a super stocker that was running in the 9's that had a 1/2" front plate and a 3/8" mid plate and a torque limiter on one side(sorry don't remember wich side) found that that the engine was wrapping arounf the other side like 3/4" at launch. So in my mind one on each side is cheap prevenitive maintnance.

quote:

Originally posted by Beretta 7.90:
As Stated for above reasons of forward and back movement you need both sides of the engine to have some kind of torque limiter.

Agreed. Next time I have the ol' Hot Rod at the chassis shop I will be installing these limiters.

EDB

quote:

Originally posted by Beretta 7.90:
In a chassis book I read at one time they found a super stocker that was running in the 9's that had a 1/2" front plate and a 3/8" mid plate and a torque limiter on one side(sorry don't remember wich side) found that that the engine was wrapping arounf the other side like 3/4" at launch.

You need to find that chassis book and set it on fire........complete bullshyt.


It's triangular support, for the "other" side to move the motor would have to move away from center. Front and midplates will not allow the motor to move off the centerline.

With your chassis book thinking.....a track locator wouldn't work either.


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quote:

Originally posted by used to like ihraprostock:

quote:

Originally posted by Beretta 7.90:
In a chassis book I read at one time they found a super stocker that was running in the 9's that had a 1/2" front plate and a 3/8" mid plate and a torque limiter on one side(sorry don't remember wich side) found that that the engine was wrapping arounf the other side like 3/4" at launch.

You need to find that chassis book and set it on fire........complete bullshyt.


It's triangular support, for the "other" side to move the motor would have to move away from center. Front and midplates will not allow the motor to move off the centerline.

With your chassis book thinking.....a track locator wouldn't work either.


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Easy there big fella!!!

Agree.

Dave

You know how much I love some of those books.






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He was asking for input on torque limiters and I gave him my opinion on what is needed or not needed. The book referance was just that And I believe it was Dave Morgans Doorslammer book But I'm sure he dosn't know what he is talking about nor do I. But I do have a ? for used to like ihra prostock Have you ever had the motor out of a crome moly tube chassis car with no plates mounted up and stand on the front chassis crossmember and just try to bounce the struts up and down ? If you have you would have seen a ton of deflection in the up strut mounts with no plates in. and thats with my 250lbs *** so imagine what 800-1600hp could do. The plates are for rotating strenght not forward and backward. Torque limiters are for just that forward and backwards. And what would the track locator half to do with anything you do have some pinion angle in your car don't you so whos to say when your car launches you may have a little more from one side of your drive shaft or the other. Just stating my opinion and what I would do and what I have done in the several door cars I have built over the years......

Ah yeah.....I might've seen a chassis without a motor in it flex a few times in my career. Just like trying to get the motorplate bolts in with the chassis on the tires vs on stands. Reason being, the chassis was designed to use the motor for strength.....without it there is none.


Track locator reference was to illustrate to you how triangulation works. That's what you have when you add 1 engine limiter to a motor held in by motorplates.

If you believe the "other side" can move 3/4".....I've got some bad news for you (and Dave if he really said that).

For information sake, it should be noted that midplate intalls vary in strength. The design we use was originally designed for clutch apps and requires no engine limiter.....got lots of clutch and auto cars with 1.0's 60' times with no adverse effects or plate bending.

If you're not sure about the strength of your midplate, or if you use the popular CE .090" steel plate, definitely install an engine limiter. One side will be fine.



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This message has been edited. Last edited by: used to like ihraprostock,

I remember seeing a doorcar about ten years ago that had a .250" motorplate and a .090 mid plate that was quite "warped".....no limiters. I have used alot of .090 plates with limiters with no problems. My current setup is a .250" front and back plates with no limiters, 1.14 60's, no trans crossmember, and no problems. This setup bolts the midplate to the sides and top of the chassis members........like "used to like ihraprostock...BEFORE HE FOUND SUPER COMP " stated above.

SUPER COMP........Yeeeeeeouch!!!


OK......so I got nothin' that runs sub 1 second sixty's. Can we put a couple of blue bottles in your car and I can tag along????





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