Some interesting progress on my 12a turbo!

[rotorhead666]

Hello everyone,the old 12at finally got her new ecu at the weekend,got rid of that nasty egi ecu,and replaced it with a shiny new microtech!also,it had the injectors replaced by turbo ii 550s,lost the distributor cap for a crank angle sensor,and got turbo ii ignition coils.the increase in performance is phenomenal,several times i thought i've been in 3rd,when it's actually been 5th!the increase in torque is extremely noticeable too,and being as the air flow meter has gone,the air filter is right on the turbo unit,so it hisses twice as loud as before,and the dump valve is even louder!the ecu isn't 100% mapped yet,but it's pretty awesome as it is.power output is around 210bhp(estimated),turbo iis beware! to put things in perspective,i had a ride in tim white's 12at,around 350horses worth.turbo comes in at 5000rpm,feels more like a jet!oh well,i'm happy with my output with my limited driving ability(only 3.5 years of driving)

[MikeLMR]

sounds cool, should be rather quick with that sort of power !

[bill shurvinton]

Just be careful at this time of year. Working 1st gens are rare (will get mine going honest) Don't want to hurt it or you.

[sideways_rob]

Yeah man, take it easy, when that turbo kicks in it is likely to spin the wheels in low gears, so don't let your rear end over-take
you! :rollin

Originally posted by bill shurvinton
Working 1st gens are rare (will get mine going honest).

Bill, how much work does yours need?

I bought my first one about a month ago, and I bought a donor one a couple of weeks ago. I hope to get 1 working one out of the 2 of them:3gears-lh

[mattmaclennan]

This is the 12A Turbo I'll be hillclimbing next year with my mate.Santa Pod Pic (http://www.mazdarotaryclub.com/club_events/Santapod_2003/Gen1_Red_1.JPG) It's kicking out somewhere in the region of 300+BHP. Tim White built the engine and me and my mate did the rest. It's down at Tim's now having a Turbo the size of a beachball fitted and a Microtech ECU. Hope to be running a sub 13 second 1/4 mile. We've had it to about 1.7 bar of boost on the original "Tim-spec" turbo, but the back plate gave way and made room for an oil leak.... well, more like an oil river.

Hope to see your 12A Turbo at one of these meets... or maybe at a hillclimb???? If you fancy it?

[bill shurvinton]

Originally posted by sideways_rob


Bill, how much work does yours need?

I bought my first one about a month ago, and I bought a donor one a couple of weeks ago. I hope to get 1 working one out of the 2 of them:3gears-lh

Good question. It had 6 months ticket when I bought it, but the 12A is very tired and needs a rebuild. So options are

1. Rebuild streeport and EFI on the 12A
2. 13B Turbo run as NA
3. As 2 with renesis rotors
4. 12A turbo
5. 13B turbo

Once the Westfield is fettled (currently 6 months behind schedule) I'll get it in the garage and start on it.

[rotorhead666]

Originally posted by mattmaclennan
This is the 12A Turbo I'll be hillclimbing next year with my mate.Santa Pod Pic (http://www.mazdarotaryclub.com/club_events/Santapod_2003/Gen1_Red_1.JPG) It's kicking out somewhere in the region of 300+BHP. Tim White built the engine and me and my mate did the rest. It's down at Tim's now having a Turbo the size of a beachball fitted and a Microtech ECU. Hope to be running a sub 13 second 1/4 mile. We've had it to about 1.7 bar of boost on the original "Tim-spec" turbo, but the back plate gave way and made room for an oil leak.... well, more like an oil river.

Hope to see your 12A Turbo at one of these meets... or maybe at a hillclimb???? If you fancy it?
Any chance of any pictures of the engine bay?i saw this car at Tim's at the weekend,and i'm not ashamed to say the engine bay really makes me feel quite erotic!:eek: My 12at won't be coming out to play until i sort the exterior out.She doesn't look too pretty,but hopefully will be getting a nice sonic blue paint job and shiny new wheels...My Microtech still needs a little fettling,but it's a good piece of kit.Any advice for a turbo upgrade?i'm not looking for huge power,maybe up to 50hp more? The aussies seem to be able to get the turbo ii units onto rhd cars...

[rotorhead666]

Originally posted by bill shurvinton
Just be careful at this time of year. Working 1st gens are rare (will get mine going honest) Don't want to hurt it or you.
Thanks for the advice Bill,but i more than know my limitations!The money i've put into this car(a hell of a lot to me)means i treat it with the utmost respect on the twisties-i only trust myself with straight line speed!It would totally break my heart if i stacked her,and it doesn't prove anything going fast round corners.as i say,if we were that good drivers,we'd all be racing drivers!but we're not.well,some of you lot are,but that's not my point! i hope the progress with your 1st gen is quicker than mine!i've had mine since the week after i passed my driving test,as a rolling restoration.It's slow going,but i don't have much money at all.the end result will be something i can be proud of forever!i am already,but she's only half way there.Good luck with your project!

[MikeLMR]

Originally posted by bill shurvinton

3. As 2 with renesis rotors


apparently mazdatrix have been having problems with RX8 rotors and a peripheral exhaust ... the seals were starting to fall into the port and as a seperate issue the rx8 corner seals ate the side housings ! (all of them!) as far as I know they are now repeating the testing with ceramic seals from mazdaspeed and different corner seals.

I did have a working 1st gen ... but now the battery is flat so i have to charge it :D + I am planning on making it even less driveable by starting to fit the front suspension parts I have had kicking about all summer

[bill shurvinton]

Yeah, thats septics for you. The aussies have them working fine with 2mm seals and I'm sure Carl is game for it.

[MikeLMR]

Sceptics ? ... that was posted by Dave Lemon of Mazdatrix after they had failure of one of their SCCA race engines ... I'll see if I can dig it out

[MikeLMR]

So much to answer -- really don't have enough time == WAY behind on my real business.

No Jesse, I don't "lurk" here - read WAY too much of it - and answer if/when I have time and the topic is relevant/interesting. -- SERIOUSLY burnt out on "THE BOOK" AND " Conflict of interest" ETC ETC !!!

No specific order:

RX8 ROTOR housings have NO exhaust port - forget about them.
Also forget about RX8 side housings until the ENGINE is approved somewhere.
RX8 ROTORS are cheaper than any others, and have higher compression. Problem is the apex seal (and groove depth). The 8's are about HALF as tall as earlier 13B's.
Pic of early beam height:
http://www.mazdatrix.com/pictures/b-engprt/apex12a.jpg
Pic of RX8 seal:
http://www.mazdatrix.com/8pics/8engine/apexsml.jpg
I ran an engine w/OEM RX8 steel apex seals at a regional late August. The seals warped about 5 thou IN at the center -- no good. The RX8 corner seals also DESTROYED a FULL set of ported side housings (was supposed to be simple test for Run-Offs back-up engine!).

Did not have time to do full dyno testing of that engine (time, money, and lost a bearing on the dyno). The partial results I did see were SAME HP as my other engine at the top, with ~15hp LOSS at the bottom.
That engine currently has "experimental" ceramic apex seals in it (on loan from Mazda Comp) and I will do more testing of it over the winter when I get it back. --- I loaned it to Tony Rivera at the Run-Offs, and he used it for Thursday? qualifying AND the race on Sunday. It seems to have survived quite fine with the ceramic apex seals and '86-91 style corner seals.

Lightened '89 rotors are lighter than OEM RX-8 rotors. Have not tried lightening the 8 ones yet. Also have not tried cutting the apex seal groove deeper for earlier seals yet -- REALLY not sure there is enough metal there!

Btw - my Comp Board request for 86-91 Turbo ROTOR housings has been approved (FINALLY). For those who don't know, I considered it a "no-brainer". They are the SAME casting with an extra water hole to the intake manifold (need to plug it), CHEAPER to purchase, and EASIER to port.

E/P 12A vs '86 13B -- I saw a little over 25hp over the 12A when we had the 38 chokes. Dyno showed 7hp increase at the top when we changed to the 42's. I'd like to think an '84-85 13B 6-port (water seals in the rotor housings) should equal the hp we had with 38's.

Glenn Jung (13B 1st gen) and I ran really equal lap times most of the Run-Offs. However, I keep coming back to Bob Neals 12A we built for him when we raced together @ Buttonwillow National -- HE set the new track record (BOTH days). The new car he is building here (at Performance Solutions in the rear building) will be better than the one he wrote off at the June Sprints. I keep trying to get him to promise to let me win now and then out here!!

13B IS more expensive to build than a 12A. Not tons though - it's all incremental. The rotors are more, + need lightening (why we are looking at the 8's), the e-shaft is more, the gears are more, the housings are more, it takes longer to port, etc. I have not priced a FULL 12A build in my computer, so I don't have exact $$ -- I'd guess $1500-2000? more.

My 13B makes the peak? hp at 10,000+rpm!! -- don't really know cause my dyno tach only goes to 10k. -- SCARES the living crap out of me!! I have never run a 13B that high!!! and had SERIOUS doubts about it when I started the season. Turns out it had over 150 dyno pulls on it + 8 races before we took it apart (after Sprints, before Run-Offs). A rotor gear retaining snap ring had shattered and pieces had damaged the rotor gear (so rotor was no good) and front stationary gear, AND we had a BIG crack in the rear stationary gear!! Makes the win at the June Sprints even more special knowing the engine was ready to hand-grenade in a few more laps!!
I'd say this adds to the increase of 13B expense over 12A -- will see more damage from the higher rpm and heavier rotating mass.
We also (as have Tony, Glen, Gary Gist, etc) had problems getting the side seals to live. We've tried porting that did not even make a full dyno run before we saw damage to them.

I do not have a firm opinion on which engine/weight to use in E/P 1st gen car where you have a choice.
I do know that after screwing around for the whole year trying to make the rear end stick on my car (that + rear Goodyear 475's that NEVER worked/came up to temp in the Run-Offs and cost me the championship!!) I re-affirmed my love of a solid axle over independent rears -- just SOOOO much more simple.
_________________
Dave Lemon
http://www.mazdatrix.com
E/P RX7 Convertible
'85 12A Pro7
20B Bridgeport Supercharged Drag Car (soon to be a drifting car??)
(Drag racing is boring)



from here http://www.coloradoscca.org/prodcar/viewtopic.php?t=2096

[bill shurvinton]

septic = septic tank = ....

Go search ausrotary. Interesting stuff to be found

[MikeLMR]

ahhh I understand now :D had me :confused:

[scooby_si]

http://www.stopstart.fsnet.co.uk/flags/usa.gif

[MikeLMR]

had a quick look over at Ausrotary (always a good read) ... looks like the aussie engine builders are machining the renesis apex seal slots to use different seals.

back to the orginal theme of the thread ... I had no idea there were quite so many quick 1st gens in the UK !

[bill shurvinton]

Originally posted by MikeLMR


back to the orginal theme of the thread ... I had no idea there were quite so many quick 1st gens in the UK !

There was a theme? Oh yes. And many more will there be in the future if I ever start my home for distressed 1st gens (well I have an acre and its easier than mowing)

[Carl]

Hi All,
Some info that might be of use is that the side housing material is not the same in the RX8 engine as it is in the earlier roaries.This means that the corner seal material is not the same either.
The compatibility of these materials needs to be carefuly selected and can only be done by testing as it is an area of science that is proven only by physical testing.
The second point is that the grooves in the apex seal slots in RX8 rotors can be machined to accept the deeper RX7 2mm ones or others types of seal.
Francesco Iannetti who is the supplier of the ceramic apex seals for Mazda competition dept has been using racers to test the RX8 seals in racing and says that they should be ready in January.
They are aware that the modified peripheral exhaust port is vulnerable to seal breakage using OEM seals on race engines.
The stationary gears and rotor gears are not the same as previous engines,and they are not interchangeble in the sense that an RX8 gear will not fit an RX7 rotor,or vice versa.
Hope this clears alittle up.
Kind regards
Carl

[bill shurvinton]

Tribology is the word you needed there Carl.

Bill

[Carl]

Hi Bill,

Thanks

Carl