Jtr Spacers For Crossmember

[BrandonsZ]

I used the 1/2" (actually 3/8" spacers + 1/8" spacers) between the crossmember and the frame for a year now frokm the JTR kit. I used them because I thought they were necessary to clear my air cleaner. Turns out I had 3/4" at the closest points between my air cleaner and the hood using plumber's puddy as a gage (like modeling clay). (Could have sworn it was almost touching, it was an illusion) so I checked the bell housing for clearance and removed these spacers. I never really drove the car much with the 6, (only about 100 miles) and after driving ~8k with the v8 I was pondering these spacers and the kickback issue. After removing them I have the following observations.

 

1. Less bumpy when turning, feels a little more stable (may have changed the camber slightly though)

2. Much less (50% less) kickback when hitting speed bumps or gutters.

3. Easier steering (slightly less resistance, maybe 25%.)

4. Less jerky on the freeway (I have the wandering problem, I'll be replacing the bushigs soon and will tow in 1/2 deg.)

 

Just my observations. If you don't need them for clearance, I say don't use them.

[ZSPEED77]

What intake manifold are you using?

[jbk240z]

I put together a 75' Z with a SBC with an Eldebrock Torker II intake and Edebrock 14" drop base air cleaner, it fit just fine. Oh, I did not use the JTR crossmember spacers.

[Forces]

I am going to be having a similar clearance problem because of my intake manifold (Edelbrock Air Gap). I think what what I am goind to do is eith get a scoop, or just go with a cowl hood. I couldn't even get clearance when I had the motor in an 82 camaro...so I am positive I will have problems in a 240Z.

 

While we're discussing JTR parts....I have heard that the reinforcement plates for the transmission cross member recomended by JTR (3"x6") is insuficient, and can cause the floor boards to warp and twist. Something that covers more surface area is a better choice. Anyone else notice this problem?

[BrandonsZ]

I am going to be having a similar clearance problem because of my intake manifold (Edelbrock Air Gap). I think what what I am goind to do is eith get a scoop' date=' or just go with a cowl hood. I couldn't even get clearance when I had the motor in an 82 camaro...so I am positive I will have problems in a 240Z.

 

While we're discussing JTR parts....I have [i']heard[/i] that the reinforcement plates for the transmission cross member recomended by JTR (3"x6") is insuficient, and can cause the floor boards to warp and twist. Something that covers more surface area is a better choice. Anyone else notice this problem?

 

 

I am using "Performer EPS" Manifold.

 

I used 12" X 3" X 1/4" thick. Had no issues or signs of warping. But most of the torque is taken up by the engine mounts, the tranny is basically on a stock rubber mount and since there is no moment arm to transmit the torque thru the trany mount, it has to be taken up by the engine mounts or the mount would rip off. I get no movement of the stick shift when under load. The whole car twists though. The plastic creeks behind the rear windows when I dip into the secondaries in 1st. I have no other frame stiffeners anywhere, but with stock tires, I am not too worried. When I upgrade to 235's I am adding a subframe from 1/4" thick 1.5X1.5" angle that will span from the front frame crossmember all the way to the diff mount. (also seconds as a skid plate.)

 

Definately would recommend against those spacers.

[Dave]

I used 12" X 3" X 1/4" thick. Had no issues or signs of warping. But most of the torque is taken up by the engine mounts' date=' the tranny is basically on a stock rubber mount and since there is no moment arm to transmit the torque thru the trany mount, it has to be taken up by the engine mounts or the mount would rip off. I get no movement of the stick shift when under load. The whole car twists though. The plastic creeks behind the rear windows when I dip into the secondaries in 1st. I have no other frame stiffeners anywhere, but with stock tires, I am not too worried.[/quote']

The front crossmember takes care of the torque, but the total weight of the engine and tranny are split between the front crossmember and the tranny crossmember. The tranny crossmember is just hanging off the thin tin floor boards. I also used plates that were about 12" long after I found my floorboards ripped on both sides.

 

I have the Auto Power 4 point roll bar in my 71 and when I slip my fingers between the top loop and the dome light finisher I can feel quite a bit of side to side movement. Someone in a thread a while ago mentioned they secured the top loop to a roof stiffiner in that area.