Mid plate vs. no midplate
 

I was told a midplate is just as important as a front engine plate on a "high" horsepower engine (above 800) due to movement in a car on a chassis dyno that didn't have one. I say it's a wives tale being they're not allowed in SS yet there are plenty of 900+ hp engines in SS/B - SS/AH with no problems.

Opinions?

Re: Mid plate vs. no midplate
 

Actually, they are allowed in SS. Just put one in mine. Section 11A, page 7 of the current rulebook.

Re: Mid plate vs. no midplate
 

Well, I'm a FFFFord guy an as such, Bob Glidden wouldn't use an engine stand. And thats on engine's not running.

Re: Mid plate vs. no midplate
 

I run a Front plate and solid steel motor mounts in my SS/AS Mustang and it makes over 900HP, I have not seen any problems as of late.

Re: Mid plate vs. no midplate
 

The use of a midplate is a plus and if the rules allows it, use it.

It stiffens the chassis and also limits the torsional twist and stresses on both the engine block and transmission.

In many cars, it improves the 60' numbers,

If you have to use a diaper, it makes the installation and removal easier.
It makes engine removal easier too.

Re: Mid plate vs. no midplate
 

Thanks. I'm falling behind with rules.:o

Re: Mid plate vs. no midplate
 

SSDivn6 mirrors my feelings.

I think it is a good addition and see no down side to doing so.

Re: Mid plate vs. no midplate
 

Re: Mid plate vs. no midplate
 

The mid-plate can only be part or integral to the firewall in Comp Super Modified class.

For Super Stock class, the firewall and mid-plate must be separate pieces.

Re: Mid plate vs. no midplate
 

Does anyone have pictures of a legal firewall in FWD converted modified they wouldn't mind sharing?

Re: Mid plate vs. no midplate
 

Re: Mid plate vs. no midplate
 

S/S Cavalier from Racing Junk ad several years ago.

Re: Mid plate vs. no midplate
 

Another one @ P&K Race Cars.

Re: Mid plate vs. no midplate
 

Here you go.

Re: Mid plate vs. no midplate
 

Would this work?
http://i178.photobucket.com/albums/w...psztfdkfqm.jpg
http://i178.photobucket.com/albums/w...psxppdq5fj.jpg

Re: Mid plate vs. no midplate
 

Anyone?

Re: Mid plate vs. no midplate
 

in my opinion I would e-mail the drawings to the tech department at nhra, or your div. tech director. to get an approval, and save or print the e mails. so if down the road there is a problem, you have some correspondence to show.

Re: Mid plate vs. no midplate
 

The design looks great as regards to stiffness from an engineering standpoint.
Nevertheless, the installation looks quite forward from the firewall.
You don't want to compromise the advantages of engine setback.

Also remember that the rule book specifies that for the Chevy Cobalt, the distance from the radiator core support to the firewall for Super Stock GT and Super Stock Modified is a maximum of 33 inches. For Comp Eliminator Super Modified is a maximum of 34 inches.

Re: Mid plate vs. no midplate
 

Just got word back from NHRA that the design would be acceptable. The spacing the model shown was exaggerated slightly to help show that there was a separation of the firewall and midplate. In reality the front surface of the midplate will only be 1" from the firewall. With the LS style engine they actually have no bellhousing flange like a traditional SBC, so the mass of the engine is already offset to the rear over an inch. The engine really has to be offset from the firewall or the head will basically be touching it.

http://i178.photobucket.com/albums/w...psqcypzpmg.jpg

Re: Mid plate vs. no midplate
 

Wasn't aware you can fab a complete firewall on a FWD GT car. Thought part of the OEM piece needed to be intact.:confused:

Re: Mid plate vs. no midplate
 

Straight from the GT rules, modified is basically the same.


FIREWALL
The lower portion of the OEM firewall may be replaced with steel
of equal or greater thickness than OEM. Chevy Cavaliers, Pontiac
Grand Ams and Sunfires, and Ford Escorts may have firewall
replaced or relocated, provided the measurement from the rear of
the radiator core support to the firewall is 34 inches maximum. For
Chevy Cobalt the radiator core support to the firewall is 33 inches
maximum. For all other vehicles, firewall must be in the original
location. A complete one-piece steel firewall that resembles OEM
must be installed, welded in place, and sealed from the driver
compartment. The firewall must extend to and attach to the floor.
The firewall and mid-plate must be two separate pieces. All motor
plates, mid-plates, etc. must be separate from and may not be
attached to the firewall.

If you look at the stock firewall, there is no way to keep in intact and do an RWD conversion.
http://i178.photobucket.com/albums/w...sqaehwfwv.jpeg