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86 RX7 with Turbo LM7 and Megasquirt

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I am officially finished with the 700R4. I tried adjusting the pressure with a gauge and made sure the TV system was set up properly, but it still won't shift. I knew the 700R4 would not carry me to my final goals, so its finished.


I dug out my powerglide core and I'm taking it to the builder tomorrow.


I also picked up the ford 8.8 rear axle this weekend. 3:55 posi from t-bird.


For my goals I decided I will go ahead and install the glide, granny's 8.8 kit and 10 point cage this winter. I will also put driveshaft loop and tranny shield in. I can't remember if the granny 8.8 kit has the loop built in?


If I can sell a couple more parts I should have the money to also complete the turbo isntall this winter since it looks like my original goal of running the car a few times non-turbo is going out the door because I'm running out of track time this year.


EDIT: as you can see this car is pretty much becoming a purpose built drag car. I will keep it street legal as long as possible, but I don't see it as being a daily driver car in the end

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The shop tore down my powerflide core and said it looked good, so now they will build it up.


I only need injectors, new fuel rail and an external wastegate to complete my turbo parts.


I also picked up the FB lower links and watts linkage for the 8.8 install. Now I just need to save the money to order the granny's kit and new axles.


I am going to start with 7psi boost and no intercooler. Once that is set up and running good I will decide my next move.


I know I always get lost reading other peoples build threads so here is a quick re-cap.


What I am working towards: (in case anyone lost track)


LM7 engine with LS1 intake/LS6 550 lift cam/LS6 springs (stock internals)

76mm turbo (start with 7psi and no IC)

Built powerglide with brake and high stall converter(haven't picked stall yet)

Megasquirt EFI, LC-1 wideband, Knocksense module

New injectors, New fuel rail

8.8 granny's solid axle



I ran the car at the track with:


Stock LM7 with stock cam (LS1 intake, stock injectors, stock rail)

Megasquirt EFI, LC-1 wideband

No turbo

Stock FC rear end

700R4 tranny (wouldn't shift to 3rd)

Street tires (big mistake)

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Once it runs with 7psi then I will at least crank up to 14psi with intercooler. After that it is just who knows.


I have 150# injectors setting around from a different project. I am thinking of running them if I can get it to idle. I will have to add a second fuel pump when I go above 7psi, that will be at the one pumps limit.


I run 18psi on my Talon. I would love to see that on the LM7 engine.



Ok, got an update. I picked up my built powerglide with transbrake and 4000 stall converter last night from the shop. I got a great deal on the converter because another guy had it built for his drag car and the stall wasn't as high as he wanted. I will have to check it for sure but it is suppose to be between 4000 and 4200. That should be a great starting point for my turbine housing size and camshaft. The shop put the stainless TH350 input shaft in my glide and that is how this converter was set up, so lucky timing. Otherwise I was going to get a converter built locally, but the price of that was much much more.


I am saving money for the granny's 8.8 rear end kit now. Once I have that I will be pretty much set up.

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I've been away for a while gathering parts. Some of these I already had but I thought it might be neat to get a pic with everything together.


76mm turbo

T6 weld flange for the turbo

60mm external wastegate (SS cheapo)

High flow fuel rails

150lb injectors (there is a story behind these because we all know I don't need injectors that big)

550 lift Z06 405hp camshaft

Valve springs, locks and retainers for the Z06 camshaft

truck exhaust manifolds to point forward for hot side turbo piping


Also tossed in a pic of the built powerglide with transbrake and 4200rpm stall converter





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Ok, finally saved up enough money for the ford 8.8 torque arm solid axle kit from Grannies. Just got off the phone with Grant and the conversion kit with caliper brackets is on order. I have the t-bird 8.8 diff already. The only thing left to order is new axles.


Here is the pic from their site:



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Got some work done on the car over the holiday break. Got the powerglide and 4k converter installed. Got the z06 550 lift cam installed, new springs, new timing chain. Installed turbo oil drain fittings on both sides of the oil pan for flexibility. I will only use one of course, but wasn't sure which side I would be mounting the turbo when I installed them.


I am waiting on the 8.8 granny kit to arrive and I will be installing that next.


In the meantime I spent about 4 hours working out the trubo install plan and here is what I came up with(I am really happy with the way it is going to work out):


Put the turbo on the drivers side where the battery use to be(move battery inside passenger compartment). The turbine inlet flange is then out where the alternator use to be(move alternator to passenger side). There is a lot of room in this area to merge the hot pipes and mount the wastegate. The charge outlet points straight down and goes through the sheet metal below where the battery use to be. The charge pipe runs in front of the radiator and comes back through by the passenger headlight(great for adding FMIC). This keeps the charge pipe out of the engine compartment to help congestion. Passenger hot pipe goes below the water pump inlet and across below/between the lower pulley and electric fan. Driver hot pipe leaves enough room for the 3-3.5" down pipe from the turbo to exit the drivers side of the engine compartment. Heat shielding for wiring harness and brake booster/MC. New fuel line down passenger side of car to stay away from exhaust. Remove driver headlight and cut sheet metal for cone filter on inlet of turbo. Turbo oil feed from tapped spot above oil filter(OEM oil cooler location). Turbo drain to ½†fitting installed in oil pan 1 3/8†below top of oil pan. Flex coupling between hot pipes. Mount for turbo. This leaves room for radiator hoses, electric fan, alternator mount on pssgr side, downpipe on driver side, etc. Start by using 2.25†dia hot pipe for each side (this is still as large as the truck manifolds).


Losing the driver headlight is not a big deal for me since I don't need it at the drag strip, only need one headlight.

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Pics from the weekend.


First, the 8.8 install so far:


Got the 8.8 prepped by cutting off all those factory brackets and grinding the welds




Then welded the granny's mounts for the lower links/shocks and watts link.




Stock rear removed.




That was the hard parts as far as I'm concerned with the 8.8 install. I did remove the seats and carpet for the next step which is isntalling the hockey pucks and front lower link mounts. I'll get more pics when the torque arm and caliper brackets are installed.


Second, the turbo install so far:


Driver side front with wiring removed.




Driver front after cutting the sheet metal to allow for the charge pipe and inlet air filter. I know some people won't be willing to do this for a turbo install.




Top view, the radiator will move towards the pssgr side a inch for clearance of the upper radiator hose. I will rewire the front of the car so the harness no longer goes below the turbine along the driver frame rail.




This picture is weird with the angle. The turbo really sets down even with the radiator support. There is plenty of room for the air filter.




One last view through the front.



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A couple new pics for you guys. Got the turbo mounted on the drivers side. Got my new fuel rails and injectors installed. Switched to truck round coils becuase they mount higher on the valve covers for clearance with manifolds flipped upside down. Also used two driver side valve covers, easier crank vent that way. Still have to finish putting the wire harness in loom, but its getting there. Notice that I moved the relay box back behind the strut tower.


4 inch downpipe is in there. Started the FMIC piping. I removed the stock fuel lines and vent line. I'll run new ones now on the pssgr side of the car now.


woo hoo, starting to get excited. All of the sudden I feel like I'm on the downhill slope. :yay:





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Passenger side mounting of the alternator. I used a timing belt idler pulley from my bucket of parts. I think it cam off my Camry. It is wider than I needed, but it works good as the proof of concept.



Another view of the alt mounting.



Upper IC pipe.



FMIC, I have some concerns with this, but I'll see how it works.


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The 8.8 install is completed.



More pics from the weekend:


Went back through the wiring and combined the harnesses



Interior, still stock



Transmission cooler electric fan, since I have the trans brake



8.8 installed, watts link, rear is hanging all the way down in these pictures



245/50R16 Drag Radials for testing purposes



300zx NA wheels


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cut a hole in the airdam to fix cooling with the big FMIC blocking the original flow.





Mocking up location for the odyssey battery.



Couple pics of the 8.8 sitting on the ground.





I got my oil drain line installed on the turbo. I finished all the hot pipes last week and went to install them last night but realized didn't have a T6 turbine inlet gasket. I put that on order.


Last things to fire up:


1. Install plug wires

2. Connect fuel lines to rail/FPR

3. Install battery tray

4. wire dropping resistors for injectors

5. connect wideband to megasquirt


I have not installed the wastegate on my hot piping yet, but I am going to fire it up and test a few things first. Then I'll get the WG installed. There is no danger of accidentally building too much boost with this setup during testing.


Here you can see how the flex joints are installed for each side of the engine. The pssgr pipe goes low under the pulley, the driver side goes up and then down the front of the engine. Both sides use the same type of stock stainless manifold, I bought two sets to get two matching pieces. I don't remember mandrel pipe loosing much flow at all on a 180 bend like you see in the pictures. I am waiting on the T6 gasket and then I'll snap a couple pictures of how the pipes route inside the engine bay.





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I started and drove the car on June 7th, then went on vacation for a week.


Got back and drove the car again on June 14th. Then basically let the car sit for a couple weeks while I caught up on other house projects. Went out to start it for my dad so he could check it out, rev'd it twice and it just died. I am not getting a crank signal to MS. I borrowed a scope from my friend today and will try to get it running again this weekend. I have not installed the wastegate yet. It is building boost around 3500-3800 rpm. The car sounds awesome with the Z06 cam. It surges at idle like a blown monster truck engine because the injectors are too big. So a little more work, but it is darn close now. I need a BOV. I alsoneed a second fuel pump so I can move to E85. Hoping to see it make around 700hp at 14psi on E85.

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Unfortunately I have some bad news from this weekend. My turbo had not been spooling the last couple drives. Keep in mind I have only driven this car in the driveway about 10 times total. I pulled the air filter off to make sure the turbo spins freely, turns out the compressor shaft got bent somehow. When you spin the compressor by hand it wobbles around and touches the housing. The turbo was a rebuilt T6 (rebuilt by detroit diesel). I have never really read of anyone having this happen before. It had an air filter on it the hole time and the blades are perfect so nothing hit them. I guess it was heat that did it?? I had primed the oil line and it built boost the first couple drives. Pretty weird, I am going to talk to Dave at majestic turbo to try and understand what could cause this before I get another turbo or get this one rebuilt. I will probably have this one rebuilt with an 88mm wheel, that was my plan for further down the road. The turbine wheel does not seem to wobble, so the bend is only on the compressor wheel end. I checked the trubo repeatedly during the install whenever I would re-clock the housings to make sure the shaft spun freely and I never saw a problem with it. hmmmm.....

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OK, 18 months later I decided to put closure to the turbo failure. Mainly the car has been setting because I have been catching up other things. My son is now old enough to be interested in the car so I had him help me pull the turbo last night and inspect everything. This is what I believe and what I found:


-- Oil supply fittings, lines, all looks good and clear to the turbo(AN -4 no restriction). Feed is from recommended location on LSx oil pan above oil filter. This is filtered oil that it headed to the mains. Pressure measures good.


-- Drain is 3/4 inch to oil pan location specified by banks install manual. Angle is not great, room for improvement here. I can blow into the drain tube and air comes out crank vents, but pressure builds in crankcase and when I let off some air comes back out drain tube. That doesn't seem right, the engine is going to have more blow by than I can blow into the crankcase, I would think??. I do not have a crank vent to intake so vacuum under light throttle will help evacuate, maybe I better do this.


-- Took apart turbo and see that brass bushings and main shaft at location of bushings look OK. No scrapes, no heat marks, shaft still spins freely in bushings. Thrust surface is scuffed and has heat marks. Front seal is shot and scraped. Compressor wheel wobbles and hits housing. No signs of damage to fins from foreign object.


-- Some Facts: Car never had a blow off valve. Car was driven about 10 times down driveway, less than 5 miles. Few hits of boost, about 8psi. Compressor always chopped/surged when throttle plate closed since no BOV.


What I get from all of this:

I am no turbo expert, but I don't see signs of oil starvation. I believe the first thing that happened was the compressor hit the housing and the shock bent the shaft. Once this happened and the compressor wheel started wobbling, then the thrust bearing made contact and heated up, the front seal wore out and that is how the turbo sets now. I think only two things would have caused the wheel to hit the housing at boost rpms, short loss of oiling (not sure how this would happen, even with crankcase pressure I should only see the seals fail and burn some oil) or compressor surge on letting off the throttle after boost run caused the wheel to shake and hit the housing. I believe the second occurred, but have no way to prove it. Remember, this is a T6 frame turbo with a 76mm compressor wheel. It was pushing some serious volume when I would let off the throttle and cause surge, I know a lot of people don't believe surge can hurt a turbo but I am convinced that compressor hit the housing because of it. I could be wrong, but I have to go with something and I don't see lack of oiling by looking at the bushings.


What I apply to the next turbo setup from this experience:

Try to angle the drain line better. Try to evacuate crank pressure better. Install a BOV from the beginning. Maybe run with the 1 quart overfill for the well known LSx sump issues.

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Hey guys, just came across another thing that could have made the turbo fail. Saw this guy on another forum talking about a turbo failure he saw when teflon tape was used on the oil feed line fittings. Some of the tape ended up clogging the turbo oil passages. Guess what, I used teflon tape on the fittings. That probably makes the most sense.


Only other thing I saw was if the car sits for long periods to re-prime the turbo oil line before starting the car. I also see that it is recomended by several folks for this turbo size to use a AN -6 feed line and AN -12 drain. I'll look into that.


Anyway, I am going to replace the turbo with a Borg Warner s400. That is a T6 frame bolt in replacement and supports ~900hp. Should spool earlier with 1.10 AR Turbine housing.

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Since I am still low on funds I am thinking of putting a stock converter on the powerglide and driving the car non-turbo this summer. Its a 5.3 with an LS6 cam so it gets around ok without boost. Guess I better put a muffler on it too :wink:

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I got some inspiration and sold a bunch of parts out of the garage so I can get this car going.


So today I put an S475 turbo and JGS 50mm WG on order. :cheers:


This time I will be using AN-6 oil feed for the large T6 turbo.


The List of things to do to get this car running:

Install new wastegate

new turbo should be drop in replacement for the old, we shall see

Start tuning


That is it...I already had everything working on the car with the old turbo. I think I'm getting excited and if you know me that is rare :D

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I worked on the car a bit over the weekend and I think I came up with a plan for this winter.


Right now the car only needs a muffler installed to be driven with MS1 running the engine and no turbo. I had already put a downpipe on the car so I could keep it running without the turbo, but no muffler. Sitting on the bench I have the S475 turbo, JGS wasteagate, new BOV, second fuel pump with dual fittings and MS3 computer, but none of these are installed.


So I think my plan will set up in three stages:


1. Put a muffler on it and drive it a couple days to work to see how everything works on the open road. The car has never been driven more than a couple miles at a time.


2. Then, put MS3 on the car and drive it some more to get tune working and colds start, IAC, etc.


3. Take the car down to install the new turbo and wastegate. At this time I need to re-build my hot piping with stainless and good flex joints that won't come apart. I also need to change my BOV and add the dual fuel pump setup. One other thing is that I need to put adjustable rear links on my 8.8 setup. I have no idea at this time what to do for exhaust with the turbo, that is one unknown. My current downpipe is 4".


Over the weekend I worked on two leaks. One was leaking from the bypass plate above the oil filter where I had tapped for turbo oil feed. The other leak is the speedo bullet on the powerglide. Looks like I have the old style bullet with only an o-ring seal and nothing on the speedo gear. So I ordered a new style with a seal on the gear as well.


Just another data point, this whole time I have kept my PC680 battery on a float charger and it still seems to work great.

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I got back to work on the car in August and got it driving in the end of November this year without a turbo.  The car is running very good on MS3.  I re-did all of the power and gnds in the car and made my own relay center.  Tucked all the wiring.  I used a copper bus bar to allow everything to be grounded together and grounded to the engine block.  The LS truck coils have their high power ground connected to the heads.  No more electrical noise issues and MS3 is awesome.  Car starts immediately and idles fantastic with 80lb siemen deka injectors on pump gas.  BTW, the PC680 battery is still working great.  I did add a disconnect switch so I can be sure I'm not drawing power while on the float charger.  I did a host of other small things that are detailed in my build thread on norotors.com, connected trans brake, did a temporary v-band single exhaust that I can swap on to run non-turbo, etc, etc


All parts are ordered to get the S475 turbo and JGS 50mm wastegate installed over the Christmas break.  This time I am using C6 L3 exhaust manifolds pointing forward.  All stainless 304 v-bands, 2.5" piping, lined flex joints, and a single divided pipe to wastegate to maintain the divided housing.


Relay and Fuse center with MS3



PC680 battery, new fuel system, tucked wires



MS3 and Tuner Studio on JimStim



New Power Distribution Schematic



Main 80 amp fuse for entire car power


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