Elfords big brother

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Th0m4s
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Elfords big brother

Post by Th0m4s »

Some time ago I bought something off Ebay which could be interesting for some of you: A RX7 SA22C turbo racecar.
I found it while I was a bit bored and searching for a FC Turbo II just for fun. The car was advertised as running but with many problems and there was some strange stuff in the pictures which I've never seen on any RX7 before like a rollcage, a strange carburetor and, of course, a turbocharger. The previous owner didn't really know what he had there and wanted to get rid of it because he wasn't able to repair it. So he started an Ebay auction beginning at 1€.
I didn't have to think long. I wanted that car because I wanted to have a RX7 again and because I was totally interested in the strange turbo carburetor thing. I even wanted to bid up to 7000€ to get it but luckily the auction stopped at 4000. Oh by the way the car had only 41000km on the clock! So I rented a car trailer and drove about 400km to pick it up. It was in a better condition than I was hoping for. No rust holes, just minor surface rust. The engine even was running but it was extremely hard to start because the carburetor never was rebuilt before.
Those were the first pictures:
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After some weeks of work, including the rebuild of the carburetor, a new fuel pressure regulator because the rebuilt carb was constantly flooding and fixing a hacked to death middle console, the car was back on the road again. I even got a historic registration for it.

A small list of parts installed in the RX7:

°rear disk brakes from the later model
°special clutch type LSD (locking up much harder than the normal one in the FB)
°spur-toothed gear box
°BAE-Turbo with Carter AFB carburetor, Rajay T04B turbo and water ethanol injection installed by Kahn Turbosysteme KG
°exhaust gas temperature and boost pressure gauge
°boost pressure regulator below the glove box
°Wiechers rollcage
°Corsa ATI 2 steering wheel
°Blaupunkt radio and panasonic equalizer
°map lamp for the passenger
°4-point belts
°Interad bucket seats
°rear seats removed
°Versatec front bumper
°Versatec side skirts
°Küwe rear bumper
°Küwe rear spoiler
°roof antenna
°glas sun roof
°5 x Atiwe 14" rims
°Koni Special D shocks
°stange exhaust starting with 76mm at the turbo and ending with 50mm at the silencer :shock:
°4 additional head lights
°metallic red paint with silver stripes from who knows when :roll:
°battery kill switch
°2 additional hood locks

2 weeks ago a good friend of mine built a new stainless steel 63.5mm exhaust for the car. This is how it looks now:
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Because of that the engine had so much less back pressure that it started running lean under boost. So to know what exactly is going on I installed a wideband AFR gauge from AEM. I know it's not exactly matching the time when the car was built but it helps me seeing if anything is wrong with the car and that's worth it.
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The fuel level gauge shows me how much water ethanol mixture is left.

By the way 2 months ago I found nearly all the documents from the original owner including bills and so on lieing under the seats. A really nice find. :D
Oh and the car has round about 270hp at the flywheel at 0.8bar boost pressure. ;)
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A7RXY
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Re: Elfords big brother

Post by A7RXY »

Great find Thomas and it looks like it's found the right owner to bring it back to health. Looking forward to more on your rebuild.
Good luck
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Th0m4s
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Re: Elfords big brother

Post by Th0m4s »

Thanks. By the way I forgot to mention that the RX7 looks like an FB bit it is a 1980 SA. This is because, at least I was told so, The car first was bought for the IAA 1981 to show the new FB appereance. So this Mazda RX7 SA got the FB body before it was on the market.
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Re: Elfords big brother

Post by TOOL »

Yeah, the interior doesn't match the exterior.
Back in the UK for the summer, maybe longer......
Th0m4s
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Re: Elfords big brother

Post by Th0m4s »

By the way I'm searching for new wheels like the BBS ones from the limited edition or other nice wheels out of the 80s. They have to be old because my car has a historic registration and to keep that I'm only allowed to use parts older than 20 years from today. As if it wouldn't be hard enough to get 4x110 wheels of any date... :cry:
I've seen the offer in Ebay where somebody is selling limited edition wheels but he doesn't want to send them to Germany from the USA. So if anybody knows anything please tell me. (hp)

I hope I didn't violate any rules by asking that question.
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Re: Elfords big brother

Post by TOOL »

It's very hard to find decent 4x110 wheels.

These? They're only 13x6 though.

http://www.ebay.co.uk/itm/Rare-Mazda-RX ... 1452535300?

What size do you want?

Try Japan.
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Th0m4s
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Re: Elfords big brother

Post by Th0m4s »

It's even harder if the wheels must pass the german TÜV. That means the wheels must be listed at the KBA or they must have papers which are approving that they are safe to use. German politicians hate people doing things to their cars... :roll:

Anyways I'd like to have 14-15 inch wheels. I'm not even sure if the 13 inch wheels would fit over the rear disk brakes. The disk brakes are the smaller version, not the GSL-SE size.

Another problem showed up today:
Because of the new much more free flowing exhaust I had issues with detonations at high speed (you wouldn't believe how fast that old car can go :ugeek: ) and I guess I tried to many things at once. I changed the gasoline form 95 to 100 octane, installed bigger secondary jets in the carburetor and changed the plugs from BR8s to 9s. Now I'm able to produce huge fire balls when I floor the pedal in first or second gear. Funny but not really what I wanted. :lol:
I'm going to change the jets back tomorrow and see if the higher octane fuel and colder plugs are enough.
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Re: Elfords big brother

Post by TOOL »

Can you put up a link to the TÜV approvals for the wheels?

Yeah, too much fuel.
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Th0m4s
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Re: Elfords big brother

Post by Th0m4s »

Sorry I can't. Only the TÜV can see them. All I know is original wheels are always allowed and all wheels with KBA numbers are allowed, too. for all other wheels I would need special papers called ABE or Teilegutachten. That's like a report about the wheels telling the TÜV guy for which car the wheel can be used and other things like durability tests of the wheel and so on.

After my work I went to my garage again, today. I changed the jets back to the smaller size. No problems so far but I wasn't able to go on a big test drive. Too late as allways...
I made a picture of my garage with both hobby cars in it. A bit small but it works:
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I also took some other pictures of the RX7 while I was at it. Sorry for the low quality handy cam. :oops:
The most important accessory (because my first RX7 died through an engine fire :roll: ):
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The seats. They are more comfortable than they look like:
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By the way they have a plate on them saying "INTERAD". Did you ever hear of a manufacturer called Interad?

Gauges and the kill switch:
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Part of the water-ethanol system made of parts like a Mercedes /8 window washer pump. The small silver box is hiding a small circuit board inside which opens a valve injecting additional fuel directly into the intake manifold above 7psi and 5500rpm. It's like an early version of an additional fuel injector.
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The angine bay. The big wash water tank on the passenger side is used for the water-ethanol mixture.
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And a picture of my wheels. I thought about what I could do if i don't find better ones for a long time and came up with an idea. I could polish the part of the rim which is silver now and paint the inner part in Mazda blue. That could look good on the car when it's painted black next year I think.
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Rotary Engines: Behold the power of two doritos on a stick!
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Re: Elfords big brother

Post by KiwiDave »

Found this relating to Interad. http://www.interadwheels.com/

US company so they may have been around for a while?
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