Summer 2010 Updates On My Bridgeported Turbo-NA Project
 

It has been a busy April and May for me. With the good weather coming early, I was kind of caught with my car sitting in my shop. And there was a local meet at the end of May that has become somewhat of a tradition, so I needed to work my butt off to get the car back on the road. The last update, posted at the end of April, was already out of date as much of the work presented in this update was well on the way to being completed. So here is that work, and probably the last update on this project in a long time save for some dyno graphs. For you see, aside from a few minor issues, I can stick a fork in it because it's done. Well, as done as something like this can ever be. I'm contemplating some body mods but that won't be for a while (I have a '76 Cosmo to restore).

Without further rambling, let's get to it. We finished off the last update with new end tanks fabricated for the intercooler. The old tank modifications I performed years ago were just nasty, so I cut them off and made new tanks from scratch. My butt dyno might just be due for calibration, but it sure feels like the car has picked up some power on the new tanks.

http://www.aaroncake.net/rx-7/projec...d Finished.jpg

In the last thread, I had painted the rear suspension stuff in POR-15 after it was all sand blasted. Here is the drivers swing arm all painted up with the poly pivot bushing and Delrin upper hub bushings installed. The stock lower pillow ball was pressed back into place. Note that for anyone replacing the rear trailing arm bushings, there is one minor trick. The stock rubber bushing has an outer metal sleeve, and this sleeve can become one with the trailing arm after many years. If your trailing arm bushing bore still has flared ends after removing the bushings, the sleeves are still in place! Cut/press them out and the new bushing will fall into place. I did not notice these sleeves were from the old bushing, which caused me two days frustration in trying to install the new bushings...

http://www.aaroncake.net/rx-7/projec...n Bushings.jpg

It was then time to reassemble the rear suspension. I purchased new dog bone links from Mazda, as well as new trailing arm cam bolts and plates. Really, much of the hardware is brand new save for a few washers and bolts that were in fine shape. The link arms seemed fine when removed from the car, so I just painted them and reinstalled.

http://www.aaroncake.net/rx-7/projec...eassembled.jpg

The hubs went on easily. All the hardware was near perfect (looks like it is Dacral coated) with the exception of the toe bushing bolts, but they were just cleaned up on the wire wheel. Actually, one of these bolts was stuck inside the original DTSS bushing sleeve. The sleeve tore from the bushing as I removed the bolt. I needed to cut the sleeve in half with a Dremel and then pry it off the bolt. The subframe bushings are also new.

http://www.aaroncake.net/rx-7/projec...iling Arms.jpg

Here's a closeup showing the Delrin bushings. The lower bushing is the toe steer eliminator. Kind of wish I had painted the bushing flanges, now that I see how the hub fits. Meh, live and learn I guess. The hubs went out to the machine shop where new bearings were installed and then I just shot them with black paint.

http://www.aaroncake.net/rx-7/projec...liminators.jpg

The new Mazda Comp diff mount was installed before the differential was bolted to the subframe. This is a GXL LSD (remember, my drivetrain is NA save for the transmission) that was fully rebuilt by a local shop. I wish I had sent the snout out for sand blasting and then POR-15'd it, because I think the black rocker-guard paint won't last very long. If it was not such a pain in the ass to remove the diff I would blast it myself (I recently purchased a sand blasting pot after adding up all the money I have spent on blasting lately).

http://www.aaroncake.net/rx-7/projec... Installed.jpg

The diff was then bolted to the subframe. The rear diff mounts are also Mazda Comp. This rear end assembly, that started as light individual components, is now pretty heavy.

http://www.aaroncake.net/rx-7/projec...r Subframe.jpg

Don't let dropping the subframe and diff intimidate you, it is actually pretty easy. Just make sure to keep all hardware soaked in PB Blaster for a few days prior and clean up all the threads before you try to remove bolts. Getting it back into place is equally as easy if you have three jacks and a helper. It probably took all of 10 minutes to raise the rear subframe assembly back into place and bolt it down (bolt it up?). After that I set about reconnecting the struts and then reinstalling the stabilizer bar. The stabilizer bar got poly bushings as well, from the Energy Suspension set.

http://www.aaroncake.net/rx-7/projec... Assembled.jpg

With my snout fully lubricated, I eased the driveshaft into the tail end of the transmission, then joined the rear of the shaft to the mating surface on the differential. Note the grease fittings on the shaft assures it will be well lubed into the future no matter how much of a pounding it takes.

http://www.aaroncake.net/rx-7/projec... Installed.jpg

From the local driveline shop, I picked up some brand new CV axles. Not bad for $85 each. The only thing that annoyed me is that the hub-side nut was different on the new part. Coarser threads and no crimp area. I used plenty of red Loctite in the absence of a punch.

http://www.aaroncake.net/rx-7/projec...l CV Axles.jpg

Everyone who knows me, also knows that I have literally spent 10 years trying to get the perfect rotary exhaust note. I was so close with the latest setup on my car, but there was a "concussion" at idle and a resonance (felt as a pressure in the cabin) at certain engine speeds. The 3" Vibrant Ultra-Quiet resonator I originally installed was doing a great job but I wanted to shift the frequency a little to fix these issues. There was space in my midpipe for another resonator so I picked up a Vibrant 3" x 12" bottle style resonator.

http://www.aaroncake.net/rx-7/projec...On Midpipe.jpg

Measured, cut, welded and done. I then heat wrapped it. At the same time I also double heat-wrapped my downpipe.

This resonator has made a huge difference. The car is nice and loud when I'm on the throttle above 3500 RPM, but below that around town it is nice and quiet. Not stock quiet, of course, more like RB Rev II quiet. The idle still has the bridgeport pulsing but the concussion of it is gone. And no more resonance on the highway.

http://www.aaroncake.net/rx-7/projec...to Midpipe.jpg

Now, it is time to move to the neglected front end. With 270K on the chassis, every bit of the front end suspension/steering was well past worn out. Bearings have been worn for 100K or so, bushings were a disaster, tie rods were loose, etc. The first step was do disassemble it all. Then, as I enjoy pushing out bushings, I removed the bushings from the front control arm. This is in most cases fairly easy to do with a large vice and a selection of sockets and tubing. The rear pivot bushing was just cut off with a Sawzall.

http://www.aaroncake.net/rx-7/projec...ntrol Arms.jpg

All the front end stuff was prepared for blasting. Everything in this image was blasted (as well as the sway bar end link mounts, not shown) except the control arms. They just got a quick cleanup on the wire wheel.

http://www.aaroncake.net/rx-7/projec...r Blasting.jpg

Removing bearing races from 2nd gen front hubs is very easy, if you know the trick. There is no need to risk damaging the hub by grinding out an area to use a punch, like many of the vendors suggest. If you have access to a MIG welder (and almost everyone does in some way or another), then you can have the races out in a few minutes. Clean up the hub and remove all the grease. Then, weld a few "ears" inside the bearing race. Then run a full bead along the inside of the race to get it nice and hot. Once the hub is fully cool, just bang it on the bench a few times and the race will drop out. If you need to use a punch, then punch against the little ears you have welded in (this picture shows three). If you are careful with the welder, there is no risk in damaging the hub.

http://www.aaroncake.net/rx-7/projec...Front Hubs.jpg

How does this trick work, you ask? Well, molten metal (from welds) shrinks as it cools. So the bead heats up the bearing race and as the weld cools, the race shrinks inward ever so slightly. The heat also breaks any bond the race has with the hub so it is free to fall out once cooled. But make sure to let the hub cool fully, because aluminum expands much more then steel and will actually jam the race in place if you try to remove it when still hot.

http://www.aaroncake.net/rx-7/projec...Front Hubs.jpg

While the hubs were cooling down I installed the new poly bushings in the front control arms. I actually felt kind of dirty plunging my lubricated fingers again and again into the tapered rear bushing hole. The control arm slipped into the well lubricated hole with very little encouragement needed.

Speaking of lubrication, is anyone else totally annoyed by the weird lube included with the Energy Suspension poly bushings? At the same time it manages to be both slippery and sticky while possessing some kind of unholy staying power. Get one drop of it on something, and it will be slippery/sticky forever. The only thing that seems to take it off is thinner.

http://www.aaroncake.net/rx-7/projec...y Bushings.jpg

The front end stuff was painted in POR-15. I much prefer the coverage of black POR-15 to that of silver but since I had an open can of silver (once a can is opened, its shelf life is limited) I figured I would paint the front stabilizer bar to match the rear.

http://www.aaroncake.net/rx-7/projec... in POR-15.jpg

I then reassembled the front end. The ball joints and tie rod ends (inner and outer) are brand new. If you are doing this job, do not damage the rubber tie rod to steering rack boot. They don't seem to be available anywhere. Luckily I had a spare FC front subframe in the basement I was able to pull one from.

http://www.aaroncake.net/rx-7/projec... Assembled.jpg

Once the new bearings were packed and installed on the front hubs, they were reinstalled onto the car. I packed them with loads of Castrol high-temp bearing grease. Remind me to look at another set of hubs to see if there is an easy way to install a grease nipple. At the same time, I bolted up the stabilizer bar. All new hardware, of course. Note that I cut away the brake rotor dust shield. It was in terrible shape and since it had to be trimmed to fit the larger 4 piston rotors anyway, I figured I would just make it go away. I can handle a little more dust on my brakes. :) The center part was kept because it provides shielding to the grease seal at the back of the hub.

http://www.aaroncake.net/rx-7/projec... Installed.jpg

When I originally installed the GT40R, I covered the turbine housing with a DEI turbo blanket. It looked awesome...for about a week. After that, the aluminum coating began flaking off. After a few more months, it was just a naked piece of heat wrap surrounding the turbo. It continued to deteriorate to the point where it was starting to just fall apart. Additionally, it really was not a good insulator. Everything in the area was still being baked by heat and with the proximity to the secondary injector and fuel hoses, I have never been happy about the situation. A lot of people have been very happy with the PTP turbo blankets and from what I have seen of them, the quality is very high. So I ordered one from PTP's eBay store and it arrived about a week later. I'm quite impressed with the materials used and the quality of the item.

http://www.aaroncake.net/rx-7/projec...To Install.jpg

I thought it was going to be a real pain in the ass to install this thing, but actually, it was rather easy. After I removed my oil feed hose the blanket rolled right onto the turbine housing. The only slightly annoying part was using the supplied stainless steel safety wire to secure the blanket. Trying to twist that stuff in an area of limited access was not fun, and the wire is quite sharp at the ends.

http://www.aaroncake.net/rx-7/projec... Installed.jpg

Because the entire suspension was disassembled, the car needed to be totally realigned. Actually, the car has needed an alignment since I've owned it but I have not bothered knowing that the effort would have been pointless with the worn out suspension. I did the best I could to line up the front wheels with a tape measure and then drove to my friendly neighborhood garage where the car as put up on the rack and properly set up.

http://www.aaroncake.net/rx-7/projec...nment Rack.jpg

After all this work, the car drives better then new. And it should, considering that there is a better then new drivetrain underneath it. No more clunks, rattles, grinding, floppy steering or pulling. I'd love to give an accurate evaluation of the DTSS elimination, but I don't think I can. Since I changed everything else at the same time, the car feels nothing like before. However I think I can say that without the DTSS, the rear feels far more conventional. I hesitate to say "predictable" because I always liked how the DTSS would make the car turn in, and I learned to drive with it instead of against it. Now, the rear end feels kind of "limp" and some throttle is necessary to bring it into line. I think this is what most drivers would want, but I'm still on the fence about it.

What's next? Well, not too much. Sometime this summer I will need to book some dyno time to fine tune at 16 PSI. I did some crude street tuning at that boost last year but there is little that can be done on the street at these power levels while remaining legal and safe. And ultimately, I want to have a dyno sheet showing 501 RWHP.

My rear quarter panels are a bit rough (a consequence of the car spending 12 years in Canadian winters before I bought it) so I need to put some thought into what will be done. On the one hand, a set of new Mazda quarters can be welded in and then the car repainted. On the other hand, a complete wide body is looking more and more appealing. The wide body, however, is a fairly large commitment. Whatever the solution, it won't be for a while because I have some other projects that need attending to.

ever thought about just posting it all in one thread? haha i just found out about your project now and its like 10 new tabs and i havent gotten back to the very start of the project.. lol

You can read the whole thing, start to finish, here:

http://www.aaroncake.net/rx-7/projecttina

How about an exhaust video??

I'll see what I can do. :) I have not posted any videos on my car to my YouTube in a while so I guess I should do an exhaust video and maybe a launch if my clutch is broken in by this weekend.

Aaron where did you get the Driveshaft done? I need mine rebalanced, and might as well get new U-joints at the same time.

As per Usual Aaron Cake, NICE WORK!!!
Can't wait to see the newest and most improved version of Tina.

Maybe on Sat in Haggersville.

Cheers
Ace IIB

This FC business is really nice and all... but I'm waiting to see progress on the Cosmo:rolleyes:

Just kidding.
My next project is the rear suspension as well so this addition to your previous build threads helps.

Oh and I like the old school torque wrench:icon_tup: I picked one of those up last month.

i read everything in like 24 hours. haha, gotta start learning how to weld. seems so very useful.

about the tie rod to rack boot, you can supposedly get it from beck arnley.
Beck Arnley (makes most of Mazda Genuine Parts):
Drivers Side: 103-2689
Passenger Side: 103-2691

i just copy and pasted that info from:
(the other forum??) /rotary_forum/showpost.php?p=103227&postcount=24

hope it helps! the work done has been awesome! also, was this car at sevenstock north? maybe why i think it looks familiar...

Aaron, I'm in need of a new front passenger side wheel bearing, and you can only order the entire hub from Mazda. Did you just use aftermarket bearings of the same size as the ones you removed? My hubs are five bolt too, so I don't know if the insides are the same dimensions but I doubt it.

Looking good, let me know how you like the 2 wheel peel when the clutch is broken in

you should get a set of those cross drilled rotors from the guy that sells them on ebay to go with all your other fancy new parts..... i paid $140 for all 4 he met me at a gas station lol. mine have held up good since last year, lots of high speed stops at the drags

I had the shaft made at London Drive Systems. I've been dealing with Matt for years and they do good work at a fair price. I think it cost $250 to havce the shaft made. That included a new front snout, new u-joints (obviously), re-use of my original rear flange (already upgraded by them years ago) and balancing.

I'll be getting to the Cosmo a little later this summer. First, the Insight needs to spend some time in my shop, then the shop needs a good cleaning, then time for the Cosmo.

I hate the click style torque wrench.

Mazda has the boots but that isn't much good on a Saturday afternoon. :)

Yes, the car was at Sevenstock North.

I just walked into APC and ordered them. I'm fairly sure that all the 2nd gens used the same bearing. What I ended up with were standard NTK bearings so I'm sure you could get them from any bearing supplier. I don't know the part number off hand and have discarded the boxes.

I'm not really interested in reducing rotor mass. ;)

Great work. Doing all the bushings is a pain. ( or was for me at least ) , but the car feels so much more solid after wards.

Good call, since pad outgassing, the problem cross-drilling solved, hasn't been an issue for 30 years.

Again Mr. Cake, great that you document your builds - love that you share your reasoning on the many choices you make on the way, not just the final product.

On Sunday, I posted a little video I made on YouTube that has some pretty good footage of the new exhaust sound:
http://www.youtube.com/watch?v=cEDp20F0R-c

Looks like a daily cruise around the neighborhood. I think some wider tires are in order soon though don't you?

sounds like your granny shifting when you should be double clutching hahahaha

love them sexy legssss.

On side note, car is looking great.

Then I'd have to widen my wheels. That's something I'd wait to do until the wide body...

Whenever my engine goes into positive pressure, the face of my boost gauge turns red. It's like "OMG! Danger to manifold!!".

And I got new shoes.

Your exhaust is sounding pretty nice for a BP. I might have missed it, but are you using the same universal type presilencer as a year or two ago? If so, it sounds like it's holding up fairly well.

Real nice job on your redone intercooler BTW!