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-   -   Turboing 12A-need advice on things (https://www.rx7club.com/1st-generation-specific-1979-1985-18/turboing-12a-need-advice-things-387255/)

Drifting rex 05-29-05 09:19 PM

If you want more low end torque, I've always heard that a supercharger does better than a turbo on a rotary, but I don't have any experience with it either. Just a guess.

grantmac 05-29-05 10:39 PM

The megasquirt is a really awesome unit. I'd recommend looking at timing control on the www.msefi.com forum. I think that the moderate boost turbo 12A would be the perfect package for you. You could adapt a T2 intake system, or you could run a set of snow-mobile throttlebodies on a webber manifold. The second option is simpler but you would have to install injector bungs in the manifold. I really like your car, I wish my D-Mod RX-7 was that light and fast.
Grant

rkcarguy 07-20-05 01:16 AM

Turbo going in, pics and some ???s
 
Heres a shot of the engine bay, getting more crouded by the minute. I ordered some RB flanges and pipe and made my own turbo manifold. Wondering where would be the best place to pipe in the external wastegate? Do I need to have it on both pipes or only one? I'd guess near the turbo is better for less heat and reversion? I got one of those carb spacers, I'm going to machine it for the fuel inj's and then make a 90 degree upper manifold then bolt the TB to it. I have NO room for a front mount unfortunately. Radiator is already barely holding the temp at bay. Well I will have to take some more photos tomorrow, they were both too big.

rkcarguy 07-21-05 10:09 PM

All my pics are too big and won't post, can anyone help?

Manifold, Turbo, and air cleaner are mounted. I've machined a 1" carb spacer for my injectors to bolt onto my Racing Beat Holly manifold. Next to fab a 90 degree housing to mount the throttle body, install the sensors, and wire the megasquirt. Then I have to take it all apart and pull the engine, because I have to take my pan and baffle plate off to install the turbo's oil drain :(

BTW the megasquirt is very easy to work with, it's only got about 13 wires that have to go to things. Programming is a little sketchy for me, luckily there is another 12A/T in town with the same set-up, so I'm going to borrow his settings and start out with that on mine.

I'm probably going to run water injection just to be safe, our events are pretty tight courses usually 2nd gear runs, and I don't get enough cooling with the lower speeds. If anybody knows what kind of flow is desirable let me know. Likle CC's per minute or something.

rkcarguy 08-13-05 06:21 PM

1 Attachment(s)
Photo's finally.

rkcarguy 08-13-05 06:23 PM

1 Attachment(s)
Another Photo.

kenn_chan 08-13-05 11:30 PM

:bigthumb:

Great to see that you are still working on that project. I was watching and waiting for developments, keep us posted.

Kenn

rkcarguy 08-15-05 04:56 PM

Next I need to get to the machine shop( i used to work there and I can buy them lunch for some mill time) and machine up my fuel rails and rail hold downs. Then I have to fabricate a 90 degree airbox for the top of that RB mani and mount the throttle body and top mount intercooler. Not much money(except for earls fittings for fuel system) left to be spent just alot of time.

680RWHP12A 08-15-05 06:48 PM


Originally Posted by rkcarguy
Another Photo.


so your exhaust is going to the passanger leg area? that is going to heat up the inside quite a bit, dont ya think?

can we get more pics of the engine bay please?

rkcarguy 08-16-05 07:57 PM

I've raced it for a season already without turbo and yeah it gets pretty hot in there when you're not moving. I finish my run and get out and let it idle a bit then shut it off. I've heat wrapped everything and installed shields that keep it tolerable. I thought about boxing in the whole exhaust area and louvering the floorboards, but thought that more airflow would probably keep things cooler all around. The MG's chassis has no space for exhaust underneath I didn't have a choice.

rkcarguy 05-05-06 11:29 PM

Ok well I'm back on the path of getting this thing finsihed up. Last year we had no autocross season so the car just sat with all it's guts hanging out. After talking to a few people I decided to fit everything up for the turbo and then remove it, re-install my header and go EFI n/a to begin with until I figure out the tuning for the Megasquirt. This winter I will pull the engine and drop the pan, and drill/tap the front housing for the turbo's oil drain. I got a massive side mount intercooler from a Japan spec 2JZ Twin Turbo Toyota Soarer and it's hose routing is perfect for me for a top mount.
I started working at another machine shop so I got my fuel rails, upper plenum, basically my entire intake tract/efi stuff completed and it's on the car and running with the MS as of last monday. I have to say I'm really dissapointed with our parts stores around here, NO ONE stocks plugs for the 12A anymore and I fouled mine clearing out all the oil I sprayed into the engine while it sat. My starter also threw a winding(it made all this nasty noise and chunks of copper wire fell out) and no one had one in stock. Schucks would order it but it costs $129 +$40 core charge!!!! Thanks to a friend who gave me used one I avoided that. All of this happened while I was trying to tune the MS and it's made things a major pita. I have to get a longer throttle cable, when I get that in I will go zip around in the lot and see how it is, and I'll also try to post some more photo's if I can keep them under the size limit.

wecycle 05-29-06 04:18 PM

injector pulse width
 
Check the Megasquirt pages for the method that allows the two banks of injectors to overlap.
That will most likely allow you to use the 450 cc injectors.
The DSMS were about 200 hp stock, so a bump in fuel pressure, overlapped injectors, or rising rate fuel pressure regulator could get you to 250 safely.
Watch the A/F and EGT at WOT when you are setting it up.

rkcarguy 07-17-06 12:16 AM

Well something bad....well we'll call it different..happened. As an engine importer I've been staring at a number of Nissan SR20DET front clips, well one got the better of me and now it's been shoehorned into the midget. I hate to leave the rotary world but the parts availaibility is killing me on the 12A. Gaskets, Spark Plugs, Starters, ALternators are all special order and way overpriced, and nobody stocks them anymore. Greenies shut down all our good junkyards up here and now all that's left is the big insurance scamming wrecking yards that never have anything and charge 80% of new list price!

I stripped the SR20 of all it's A/C and P/S stuff, and swapped out the turbo mani for a tubular one and managed to get the whole swap down to 418lbs, about 20lbs heavier than my 12A with the turbo stuff mounted. it's blocked up where I want it to sit this week it should be mounted and wired up, I'm waiting on a flange kit so I can do my exhaust. If you are interested in my pics I will continue to post progress even though I have rebelled..........

blwfly 07-17-06 12:36 AM

there is allready another member with the same kinda motor i say show us more pictures of how you have the nissan motor in there

nad sell all ya rotary related stuff to uss:)

No_Rotor_RX7 07-17-06 06:00 PM

pics mang... PICS!!!! not all of us are haters ;)

rkcarguy 07-17-06 08:31 PM

I will work on getting some pics posted. Looking forward to feeling that 202ft/lbs of torque at 4000rpm.....

wecycle 07-18-06 02:21 AM

Killer combination
 
Your car reminds me of Bob and Marylin King's rotary powered Emod car.
Very impressive to watch.
I think he went SCCA national champion 7 years in E mod and she nailed 8 years in E mod L.
Very frequently went FTD!
Now that they allow tube frame "mod" cars the true modifieds are harder to make competitive. Sounds like turbo power and the chassis mods you have could just do it!
Looks like great craftsmanship as well.

rkcarguy 07-27-06 10:17 PM

3 Attachment(s)
Heres some pics of the swap in progress. I have the motor mount supports tack welded in place. Wiring will be easy the nissan harness is one piece, just need to hook up the proper powers, ground, and start signal. The exhaust is going to have to go across behind the head and out the pass side like it was on the rotary, no choice for it to go anywhere else.

rkcarguy 07-27-06 10:31 PM

as you can see the manifold is very close to the top of the footwell, I'm going to be cutting this edge back and welding in a piece of sheet metal with a 45 at the top. The brake proportioners will have to be relocated along with angling the brake booster support down at a 45 to clear the turbo. The radiator I was using on the 12A will work fine, it's a little smaller than the SR one but twice as thick, I just had to have the top fitting relocated to the other side. It's opened up alot of room up front despite the engine being alot taller because of no oil cooler. I would have liked to go back more with the engine but I have a 2nd gen rx7 rearend in this and there is only going to be a 12" driveline as is sits now.


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