My 1974 REPU Project

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speedjunkie
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Re: My 1974 REPU Project

Postby speedjunkie » Mon Nov 14, 2016 9:14

I always thought they were a pretty solid company. I hope it works out without more hassle. Maybe they're doing some research on it before they get back to you again? Not sure.

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VRx8
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Re: My 1974 REPU Project

Postby VRx8 » Mon Nov 14, 2016 9:14

Glad you are going with a Haltech. If you have any questions hit me up.

As far as the FD FFE Trigger wheel, make sure that the sensor mount lines up with the trigger wheel first.

The FFE Hall effect mount is made for the trigger wheel that mount in front of the pulley like the one you have. I thinking since the FD trigger wheel mount behind the pulley it will not line up with the hall effect sensor ??

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chickenwafer
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Re: My 1974 REPU Project

Postby chickenwafer » Mon Nov 14, 2016 9:14

Alright, finally got stuff solved.

Eduardo- you're right, the wheel I have lines up on top of the main pulley, whereas the FD pulley is behind. Besides, there is no way to bolt the trigger wheel to the FD main pulley. The sensor bracket wouldn't line up for an FD trigger wheel.

So I use the REPU pulley, and it lines up. But obviously it doesn't line up with the water pump or alt pulley. So now I'm switching to the REPU water pump housing. I ordered a new GSL-SE water pump as mine was old and hardly spinning. It lines up fine on the REW front plate but the REW front iron does have an extra mounting hole that the REPU housing lacks. Hopefully it doesn't leak...

Main reason I wanted to use the FD water pump/tstat housing was for the water ports/barbs for the twin turbos. I still have the throttle body coolant port on the rear iron I can send into the twins, but need a return. So I may have to drill and tap a fitting into the tstat housing or the radiator. I'd rather send it into the radiator because if it returns into the tstat housing then it completely bypasses the radiator.

The GOOD news with the REPU housings is the radiator hoses should line up much easier so I can run a REPU style radiator. It will be moved back slightly to accommodate the FMIC core but overall shouldn't be bad. Also means I can sell my FD housing and the FFE idler pulley (anyone want either? LOL)

So I'm now running the REPU front cover, water pump/tstat housing, pulleys, and oil pan with pickup with GSL-SE water pump, REW S7 engine with twins and JDM FD 5-spd trans. Becoming quite the Frankenstein but hopefully it all works out!

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RX-7 Chris
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Re: My 1974 REPU Project

Postby RX-7 Chris » Tue Nov 15, 2016 9:14

I might have a good water pump and housing sitting in the garage.

On my old RX-7 I converted to an FC water pump and housing because it is lighter. It is a direct bolt in.
1984 RX-7 GSL-SE [size=84]My restomod project[/SIZE]


1964 Ford Galaxie 500XL flat black w/ white interior, 2 dr fastback, 390 thunderbird, C6 auto, 2500 rpm high stall converter, shift kit, AC, Holley 750 cfm

[size=100]RIP 1983 RX-7[/SIZE]

My Car Blog

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chickenwafer
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Re: My 1974 REPU Project

Postby chickenwafer » Mon Dec 05, 2016 9:14

Alright,

Haven't updated in a while, been busy with other things lately and got REALLY discouraged with numerous setbacks with the REPU. It basically all revolves around the engine and timing/crank trigger setup.

So, to recap, I'm running a 13B-REW engine from an FD, which has it's motor mounts on the rear of the engine. The stock REPU 13B engine has it's mounts on the front of the engine bolted to the front cover. To make the engine as plug n play as possible, I swapped the REPU front cover, which bolts up fine, to the REW engine replacing it's front cover. I also swapped the REPU oil pan and pickup tube since they are different than the REW engines. No problem.

The issue all stems from the timing pickup. On the REW, this is on the front cover, which is now swapped. So I need a way to pickup engine timing. The REPU front cover has a distributor hole so I could installed the FC RX7's CAS which goes in there, but it is notoriously inaccurate and allows for a lot of "float" which can add or subtract as much as 7-8* of timing at high RPM, which can cost you a motor. No thanks.

So I find that Full Function Engineering makes a CAS trigger kit for the FC and it bolts up with a trigger wheel and bracket for a hall sensor which is great. So I order it and think nothing of it. Time comes to stack the front assembly and I notice there's no way to fit the stock FD pulleys and the crank trigger wheel FFE supplies. I can't swap to a different trigger wheel or the sensor doesn't line up. OK...I can get it to work with the stock REPU pulleys, which fit differently and now don't allow the belts to line up with the water pump or alternator from the REW setup. GAWWW

Now I swap on the REPU water pump and alt bracket assembly so the belts line up. Success! I finally have this figured out! Not. The REPU water pump housings sits further back towards the block and now hits the secondary fuel rail! God damn! And of course I already bought upgraded 1300cc drop in secondary injectors. I could get an aftermarket secondary rail and injectors which would sit taller and clear the housing, but the REPU housing doesn't have the sensor ports or coolant feeds for the turbos. One thing after another.

After much contemplation I decided to just to with an electric water pump setup for multiple reasons. First, it's superior to a belt driven pump setup as water pump impeller speed is no longer fixed to engine RPM, meaning at idle I can have full coolant flow. It can also continue to pump after the engine has been shut off to prevent hot spots and localized boiling. Lastly, it looks MUCH cleaner and means I can run a small adaptor instead of a giant water pump housing and route the hoses easier. Not sure how much but it also cuts some parasitic drag off the rotational assembly as the engine is no longer physically driving a water pump now. The only thing driven off the belt now is the alternator.

It's a little more expensive but I should be able to sell off some stuff to recoup most of the additional cost. It's not that much more coin and I think the performance trade off it worth it. The Haltech ECU will also be able to variably control the pump with it's PWM output like how it would function the stock OMP.

There are some challenges, mainly all hoses will need to be custom made, but shouldn't be that expensive. I will need to an adaptor fitting to "T" into the hoses for a coolant temp sensor and I'll still need to plumb into the coolant feed/return for the turbos. There's still the throttle body coolant hose barb on the rear iron I can send into the turbos, I just need a return. I'm thinking of having a hose barb welded straight on the radiator end tank so the turbos just dump back into the rad.

Lastly, without a giant water pump housing, I need somewhere to mount the alternator now. I happened to see this New Zealand company called Franklin Engineering make a Facebook post about some of their custom rotary projects right at the same time i was planning this setup. They make a sweet side mount alternator setup. I've ALWAYS wanted to do a side mount alternator because I think it really showcases the look and small size of the rotary without a giant alternator being the front and center focal point. So I jumped on it. They shipped it real quick and I just got it yesterday. I can't install it without dropping the engine in so that should hopefully be happening soon.

Sorry for the long rant but hopefully this will be getting back on track soon now!

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speedjunkie
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Re: My 1974 REPU Project

Postby speedjunkie » Sun Dec 11, 2016 9:14

Good grief man, I didn't know you were running into so many problems. Is there a specific place you have to put the coolant temp sensor? Would it be possible to put it where the stock one is on the rear iron? I'm assuming you're using a sensor there for some reason already, but Chris tapped into my aftermarket oil sensor (can't remember if it was temp or pressure) to send to the ECU. Maybe you could do something like that.

If you could set up some other kind of charging system you could ditch the crank pulley altogether, NO PARASITIC DRAG! lol

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chickenwafer
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Re: My 1974 REPU Project

Postby chickenwafer » Mon Dec 12, 2016 9:14

Is there a coolant sensor port on the rear iron? I thought it was just oil press/temp? I think the stock temp gauge has a sensor there perhaps...I could use that and that would be perfect.

No updates as of yet...waiting for parts and time. Weather is cold and snow is preventing me from getting the engine dropped in, but it's ready to go. Biggest pain will be the transmission since it won't line up with the chassis. That will require custom mounts and cutting the floorpan for the shifter. Otherwise the engine should just drop in.

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speedjunkie
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Re: My 1974 REPU Project

Postby speedjunkie » Mon Dec 12, 2016 9:14

Yep, it's right next to the oil pressure sensor. It's very small so it's easy to miss. The threads are 1/8 BPT, which is really close to NPT but not quite. LMS-EFI has an adapter on their site. I also found one on eBay for about $6. Unless you just use the stock sensor, I'm not sure what kind of connector you have. The stock sensor is basically just a spade connector on the back.

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RX-7 Chris
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Re: My 1974 REPU Project

Postby RX-7 Chris » Thu Dec 15, 2016 9:14

I used an FC water pump housing and pump. There is a place for a coolant sensor on the back of the housing. The stock truck thermostat housing will bolt to it and you are able to use the stock radiator hoses.
1984 RX-7 GSL-SE [size=84]My restomod project[/SIZE]


1964 Ford Galaxie 500XL flat black w/ white interior, 2 dr fastback, 390 thunderbird, C6 auto, 2500 rpm high stall converter, shift kit, AC, Holley 750 cfm

[size=100]RIP 1983 RX-7[/SIZE]

My Car Blog

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chickenwafer
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Re: My 1974 REPU Project

Postby chickenwafer » Thu Dec 15, 2016 9:14

speedjunkie wrote:Yep, it's right next to the oil pressure sensor. It's very small so it's easy to miss. The threads are 1/8 BPT, which is really close to NPT but not quite. LMS-EFI has an adapter on their site. I also found one on eBay for about $6. Unless you just use the stock sensor, I'm not sure what kind of connector you have. The stock sensor is basically just a spade connector on the back.


Sweet! Thanks for the tip. That should work perfectly.

Soooo when you coming back up here to help me drop the engine in?? LOL

RX-7 Chris wrote:I used an FC water pump housing and pump. There is a place for a coolant sensor on the back of the housing. The stock truck thermostat housing will bolt to it and you are able to use the stock radiator hoses.


The REPU thermostat housing/water pump assembly bolts up too, but just as with the FC housing, it will still hit/interfere with the stock FD fuel rails. The FD w/p housing is "spaced" or gapped about 2.5 inches further, which is what offsets the pulleys further out, and allows for clearance for the fuel rails.

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speedjunkie
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Re: My 1974 REPU Project

Postby speedjunkie » Thu Dec 15, 2016 9:14

Not until after new years at least. My mom will be here from this Satruday until the 6th. Other than that, it depends on when I'm working.

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chickenwafer
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Re: My 1974 REPU Project

Postby chickenwafer » Tue Jan 17, 2017 9:14

Not many updates as the REPU stalled out during the holidays due to lack of funds and just plain being too busy to find any time to wrench.

Planning on getting back on track by getting the engine dropped in either this weekend or the next.

I was also planning on running stock twin turbos, but I'm still kicking the idea of going to a response style single turbo setup, like an EFR 7670 with internal gate. Those turbos are just so damn expensive LOL.

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speedjunkie
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Re: My 1974 REPU Project

Postby speedjunkie » Thu Jan 19, 2017 9:14

I might be able to make it up there this weekend to help.

Have you talked to Andy about an EFR? He has really good deals on them. Text me if you want his number or if you want to talk about it first.

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chickenwafer
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Re: My 1974 REPU Project

Postby chickenwafer » Mon Jan 30, 2017 9:14

Finally some worth updates!

First off, BIG THANKS for Eric and Matt who helped me get the engine and trans dropped in the REPU! Thanks a million guys!

Overall, the process was pretty straightforward and no one lost a finger. Matt and I lowered the engine in while Eric lined up the transmission from underneath. One benefit to working on a REPU vs a car is you don't need to jack it up to get under it LOL! We actually got a lot more accomplished than I had anticipated.

Engine and trans are in (trans isn't bolted in or connected to driveshaft) but engine is bolted and trans bellhousing is bolted up, Eric did the RX-8 starter mod for me so he swapped the nose cone from the FD starter and put in the RX_8 starter guts and solenoid so that's in, clutch is installed and engaged with shift fork attached and slave cylinder bolted in.

Image

And no, the alternator isn't attached in this photo. And only the primary turbo is attached and a lot of other things are missing, but the bare pieces are there!

Cool pic with the turbo lurking behind the old school Mazda grill:

Image

So, problems, because there always are some:

First, the Franklin alternator bracket doesn't work. It sits the alt too low and it hits the frame. Not really any easy way to combat the issue other than get a different bracket. So the Franklin bracket is for sale if anyone wants it and I'm going with a Kyle Mohan Racing (KMR)/Built2Apex (B2A)/Mazdatrix bracket (seriously how many different companies can be attached to a single piece??) that looks like it raises the alt about 3 inches from the Franklin pieces which should clear everything. Once again the front cover/front driver accessories proving to be the most difficult part of this swap LOL. If this doesn't work I'll just do what I should have done originally with using a stock FC CAS in the front cover distributor hole, they are much less accurate but it would solve all of this.

The stock downpipe doesn't look like it will clear between the frame and the turbos. I anticipated this so wasn't too bummed when I would out. I have one more trick to see if I can get it to work, otherwise it will be hood or fender exit for me!

In the first pic I have the black throttle body elbow piece installed. It JUST clears the stock brake hardlines. I want to use the GReddy aluminum elbow which is bigger and also makes the pipe about half as long, which is beneficial because as the pipe sits now, it curves the wrong direction and will make charge piping difficult and longer than necessary. There's no way the GReddy elbow will clear the hardlines though. So I'll need a tubing bender and move/bend the lines out of the way, and even then hope the elbow doesn't contact the brake master.

Overall, however, I'm very happy and now with the trans in I can work on getting the shifter hole cut and driveshaft modified.

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chickenwafer
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Re: My 1974 REPU Project

Postby chickenwafer » Wed Feb 01, 2017 9:14

Tonights progress

Image

Image

Twin turbos assembled, installed, rear intake pipe, y-pipe, oil filler neck. Feeling pretty good.

Also, I ripped out the stock REPU bench that was trashed and see if the spare RX-8 bucket seat I have would fit.

Image

Image

It does! And looks great, super comfy, and I already have one so it's free! I will buy another one (obviously) so I have two matching RX-8 seats. The one I have is actually a passenger seat so I need a drivers seat. It will take some customization of the RX-8 seal rails but overall I don't think it will be that difficult (famous last words)


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