anyone using top hat mounts for their rb25??

[Turboed240sx]

wondering if anyone here is using top hat mounts and if yes where did u get the drie shaft??

[Tictakman]

im using both driveshaft and mounts from them. they worked out great but havent gotten the car running yet so i cant say about the feel of it.

Zak

[Darius]

If you have an S14, be ready to make some modifications. If you have an S13, you shouldn't have a problem. You can also get a custom driveshaft made for about $220-250 if you bring in the Z32 yolk and your old driveshaft yolk.

[Kansei240sx]

I am using top hat mounts with my RB25 swap and i just had a local driveshaft shop here in town make them.

If you dont have a stock RB25 driveshaft, The yolk is a 300zx z32 yolk and slides right in.

The driveshaft lenght will be about somewhere in the neighboorhood of 43-45 inches long depending on how you MOUNT both transmission and x member mounts.

[Kansei240sx]

Haha, Darius beat me to the punch. One minute Earlier!

[Darius]

I'm quick like that...just ask my girlfriend jk of course.

I ended up measuring out 41.75 inches from the differential flange to the Z32 yolk knuckle installed in the transmission. Back off 1/2" to save room for play and prevent your transmission from failing, left me at 41.25". I have a J30 differential and I believe it's slightly longer than the 240 stocker because I had a tougher time getting the shaft back in when I did that swap.

[Tictakman]

hahaahha, nice.

[anyotherone]

What modifications are needed to use them on an S14? Are you talking about welding them to the crossmember and banging to firewall in?

[andrewmp6]

darius how well does that mckinney down pipe fit with the tophat mounts

[Darius]

It actually fits perfectly except it's a tiny bit too close to the underside of the car. There is a couple of small bolts that run along the centerline of the downpipe and cause some interference so I am going to NAPA today to pick up a flange to place between the downpipe and elbow to space it down about 5mm or so.

[nukeone]

I just installed an RB20 in a 92 'vert using the Top Hat mounts with an AUTO transmission - had used them before, but never with an auto. Driveshaft was 2" too long but everything else fit very well (with a little persuasion). Stock KA driveshaft shortened and rebalanced for $75. What I like about using the THP mounts is that I can easily mount the engine and tilt it to add the transmission from underneath, easier than with the stock RB crossmember. I kept my 5-speed 6-puck clutch, lightened flywheel and 5 speed transmission in case the auto gets too boring.

[Darius]

What I had to do to get my mounts to line up correctly was drill another hole in each side of the crossmember because the mounts lined up too closely together. As a result of me not being perfectly aligned or the car not being exactly square, I had to notch out several of the slots on the transmission mounting bracket. Wasn't what I expected after paying that much money for a couple of simple welded metal brackets. I thought it would be a bolt-in job and it was definitely not. Anyway, I had to bang out the firewall a bit and a little bit around the speed sensor. Other clearances were good. Haven't gotten to try out the hood clearance though.

[fly240]

Kansei240sx...how's the fitment of your engine, does it sitting lower in the bay? Do you have to dent any firewall, and from what I understand, you have to use the stock ka crossmember for these top hat mount right?...

[Kansei240sx]

My engine sits about 3 inches if not 4 inches lower than the KA did becuase of how far below is sits from the strut bar which is an improvement, the shifter sits in the direct center of the hole but i will need to drop the engine back out to dent out the firewall on both sides a little bit becuase i test mounted the transmission by itself and it fit but when the engine was in it pushed it back 2 inches and sits against or about 5 mm's away from the firewall so when i turn the engine off the engine shakes a bit and it knocks just a bit, but ill fix it later.

[anyotherone]

Good to know... I'm glad the motor doesn't sit too high.

[fly240]

so is this done by using the stock ka crossmember or rb crossmember with top hat mounts?.

[Darius]

Top Hat mounts are designed to be used with the stock KA crossmember.