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Some 5m-gte questions-

4K views 24 replies 8 participants last post by  MKIIBeater 
#1 ·
Hey all, I'm the owner of a mk2 and a mk3 turbo supra- I was thinking of doing a 7mgte swap, I decided against this for cost reason... my mk3 is in very poor condition -engine wise- The head is shot and the rest of it is beat on, however the turbo/manifold and intercooler are still good.

Since I have a complete turbo set up already, all I would need are the oil feed lines and a RRFPR correct? And to fabricate an exhaust set up-

So I did some searching on reliability- does adding the turbo to the 5m make it much less reliable? Does the stock head gasket hold up at stock boost (6-8psi) or should I go with a 7m metal head gasket/arp studs? This would add cost but still be less than a 7m conversion...

Also, I've read about how the oil pan must be tapped into, is there any way to do this without taking the oil pan off? Can the oil pan be removed with the engine still bolted into the car? I searched on this but couldnt find anything...

Im not looking for monstrous power obivously, just want to give the mk2 what it should have come with from the factory- a turbo :D

thanks
Chris
 
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#3 ·
The oil lines you can get from www.rabidchimp.com. Aaron sells a kit. You do have to tap into the pan, but I would not suggest doing it while it's on the car. You can loosen the motor mounts, jack up the engine, and the pan will come out. Then all you need is RRFPR and DP. The reliability of the 5m will go down some. It was not meant to be turbo'd, and the RRFPR way of adding fuel is really just mickey mouse (though it will work fine), as you would need a new computer setup to do it the "right" way. That doesn't mean your 5m will not hold. It should hold no problem. Stock HG will hold stock 5.5psi boost. Or it can explode the 1st time you hit the gas (rare, but possible). Heck, I threw a rod on my 1st 5m from just raising the compression back to stock with a valve job on my worn out head. With the money you'll spend on the custom stuff to support the turbo, you can throw in 500 more and just rebuild that 7m and swap it in there, as it sounds like you're going to be junking your mk3.
It's up to you.

Christian
 
#4 ·
You cant just tap the oil pan. It is WAY too thin. You have to have a fitting bolted or welded (braized) into the pan. You can get the pan out while engine is in the car. Here is my post on it:

http://www.celicasupra.com/phpBB2/viewtopic.php?t=1627

I would not try to run boost on the stock HG. Get a MHG. Check the resources listed above. ARP studs may require a little milling of the head as they are shorter than the 5M bolts but they work great. I recomend them. If you dont use them at least get new head bolts.

Good luck.
Mark
 
#5 ·
ok so I go 7m then

Ok, if I decide to go 7m then- I have a complete mk3 with an engine with a bad cyl. Head, I can get a new head and have it rebuilt if neccessary.

So:

Well first off I make sure the Mk2 being swapped into is swap worthy (all suspension, brakes and stuff)

new head - $??
I will need a Metal Head Gasket - $175
ARP Head studs - $100
Oil Filter Relocation kit - $??

Will the R154 work with the stock drive shaft? I know I may have to bang out the tranny tunnel a bit but eh thats easy enough.

Tranny could use a rebuild - $500??
New good Clutch - $300?

This is getting expensive quick....

So now the wiring: This part scares me, I dont know if I could do it myself... despite being fairly effecient at such things. It just scares me- How hard is it? Any tutorials? And are there any people who make a service out of doing the wiring for people for a decent price? Any people who are minnesota who have done it and are willing to help should I decide to go this route?

I've also read about the oil feed pick up and oil pan needing to be modified... cost? More info-

This looks like a daunting task.........

Thanks for all the help
Chris
 
#6 ·
I am approaching $5000 for my 5mgte. But that includes racing clutch, boost controller, SAFCII, complete rebuild with balance, .020 bore and line bores as well as a few hours of dyno time (which I am going to be doing tomorrow).

It gets exspensive FAST!
 
#7 ·
Here is a great writeup on the wiring: http://andy.supras.org.nz/Wiring_files/WIRING.HTM

For the pump, it's easiest to use a 5m oil pump with a 5m pan. No modding necessary. It's been said, and from my own comparisons I agree, that the 7m pump flows no better than the 5m.

How bad is your head? Is it warped or cracked? If not, a valve job and resurface is all you need to make it fresh again. ~$150-200 (can actually vary a lot depending on the shop). If you do get a rebuilt one, DO NOT use Topline. They're good for other stuff, but I got a "rebuilt" head which supposedly had all new hardware. POS came with used valves, the margin thickness for the valves were under spec, and I could've done a better valve job with a dremel and a stone wheel.

MHG, much cheaper. Contact me if you want a better price on that.

Why use your r154? Unless you're going to put out a whole lotta power right off the bat, the w58 will hold fine.

THe reason I suggest the 7m is that right off the bat you have more power than the 5mgte. Plus, you can get much more power out of the 7m if you want to go that route later. With the 5mgte, it'll take more work and money to start extracting more power out of it. And you're in a good situation since you already have the mk3 as a donor car. If you didn't have that I wouldn't suggest going 7m since finding a mk3 adds substantial cost to the endeavor.

My 2.5 cents.

Christian
 
#8 ·
thanks

well thank you, this post has been most informative and I will most likely go 7m mk2 now :D

The head on my mk3 is quite bad, its warped badly and the valves are all out of wack- many of the stud wholes are bad as well. Where can one find 7m heads readily?

Wiring still scares me but eh I think I can manage.

Now I think I will find a really nice/clean mk2 to use as the recipient car... and keep the old less than nice (though reliable) mk2 as a back up/parts car.

Thanks all
Chris
 
#9 ·
not to make your decesion harder but heres a few more things to think about....

Overall a properly swapped 7m should produce a more effiecent and reliable motor as you will basiclly be running stock toyota efi electronics with no mickey mousing (untill you start upgrading at least). Definatly the best setup but alot more work then a 5mgte due to the wiring and the fact your swapping a different engine in. Probably worth it in the long run, but....

One more thing to think of. I'm only mentioning it as you have the perfect parts to do it already in your possesion, for most its not worth considering. As far as turboing a mk2 with the stock efi, the holy grail is a 7mgte\5mge frakenstein hybrid. The 5m head will bolt onto the 7mgte block as a 7mgte block is basiclly just a 6m with oil squirters and differnt pistons. The advantage of this setup over everything else is you get a 3.0l built from the factory for turbo duty block with a head that will outflow a 7m and has bigger stronger valves for when you take it up a few notches. The 4 valve per cylinder thing doesn't really do a turbo motor much good, its more on an NA thing. The other advatage is you can run it with the stock efi and avoid the wiring nightmare. Since your 7m head is toast this obviously would work very well for you. The downside of this is once again you will be using the inferior 5m efi and will need a mickey mouse bandaid solution like a rrfpr or big ass injectors and a SAFC. BUT, it might be worth your time to go this route as the intial cost would be cheap compartively, then later you can switch to a standalone efi system and have the absolute best of everything. You will need to switch out the pistons from the 7m as it will become an interferance engine with a 5m head on it. 82\83 5m pistons would work but what would really be best would be to invest in some custom low comp forged pistons. The money you save not buying a new head and paying for a new wiring harness should cover thrm, and once again, you will have the ulitmate setup in the long run if you go standalone. 5m head, 7mgte bottom with forged low comp pistons, 7m oil cooler, 7m turbo bits + standalone efi would be bloody awesome. You may actually need that r154 eventually if you go that route :D Theres a post about using the r154 in a m2 around right now, it is doable and easier then expected.

Did someone once say 7mgte pistons aren't forged? I thought I heard that, anyways some good custom ones should be stronger the stock 7mgte ones.
 
#10 ·
good idea...

Do the good ideas ever stop flowing :D seriously... I love you people.

So the block is a strait "bolt on" per say? No fancy re-wiring or plumbing? Just different pistons and thats it? This sounds to me like the best/easiest option...

7m pistons are not forged- The 83ish 5m pistons were lower comp. right? But they aren't forged and wouldn't last all that long in a High HP engine... wich it will probably turn into not too far into the future. Any estimates as to how much some of those custom pistons may cost? Stock 7m rods are good to 400-500 I've learned so they should hold.

Then all I need is a rather large hair-dryer and I'm set.

I gotta start saving my pennies...

Thanks
Chris
 
#11 ·
If the motor is in that bad of shape in your Mk3, you might want to consider getting a JDM 7MGTE and fitting it with a MHG. You could probably sell some of the parts off either motor to make up some of the cost (i.e turbo, manifold, etc.). Then use the rest of the electronics and such from the Mk3 to complete it. If you have a donor car to do the swap I would without question do the 7M swap. The wiring itself is fairly simple from what I've seen. I would sit down with a Mk3 wiring manual and circle everything that goes to the engine/ECU and find the equivalent on the Mk2. Most of the wiring is changing the plug for the harness that goes to the gauge cluster.
 
#12 ·
82/83 pistons are 8.8 compared to the 9.2 of the later ones. They're also flat top. I think you can run up to around 10psi safely with them but others here would be able to give you a more accurate figure. As far as I know there should be no mods needed to get your 5m head onto your 7m block, might be a couple 5m sensors you may have to transfer over. Your 7m oilpan will not work as well I belive, theres a few options for that, Junkie on this board would know for sure. Custom pistons run in the 800 to 1000 us price range I belive. If your 7m bottom is half as worn as your head, a I rebuild would be a good idea. But if your just rebuilding the bottom and putting new pistons in anyways, then the cost would be pretty cheap, cheaper then buying a jdm 7mgte that has god knows how many miles on it.
 
#13 ·
7m block

I feel that the 5m/7m-Hybrid is the way to go and least expensive/easiest for me- and will yield the best results.

Why don't the 7m pistons work in the first place? The standard compression ratio is 8.45:1 and the pistons are flat tops or slightly concave as I recal (from a head gasket job... this is how I know the head is trashed)

I dont know how good the bottom end is, I never took it out of the car to be checked. Upon taking it out of the mk3 I would have it looked at and inspected (and have it decked for a MHG while I'm at it) -rebuilt if needed-Same proceedure with the 5m head -resurface and rebuild if needed-

The 5m has a knock sensor on the block correct? The 7m has 2 knock sensors, Im sure that would have to be swapped but would be easy. What other sensors...?

How about thigns like the 7m water pump and ac compressor- would they work fine or would there be some customization involved? I can just take the oil pan and pump off the 5m and use that on the 7m block as someone told me I could do.

I will need a RRFPR- How about injectors? Im assuming I will need something bigger- 295's?? Or could I use the stock mk3 turbo 440's? I would have to mess with the afm then wouldn't I? How about one of these MAF conversions people are talking about? Would that solve the EFI problems? Just use some 440's and a MAF conversion? Or standalone- I read about the MegaSquirt ECU in the engine forum, this would work to solve the EFI dilema right? And its cheap-

Gotta go over all the angles before I decide to actually go through with this...

Thanks all
 
#14 ·
7m pistons will technically not work because it has 4 valve reliefs instead of two. But, the pistons are non interference, which means even though it doesn't have the reliefs, it will still clear. MikeL put a 5-7m together while using the 7m pistons. It works but I would go with the 5m pistons anyways. Forged ones will run you about 100 or less each. IIRC, the 7m pistons have the wristpin set higher, so you may actually need to make a hybrid of the two (any piston manufacturer could do this). I'm not sure on this so get more info before you take my work for it.

The only way you'll get 440's to work properly is with a stand alone. If you're in a hurry to get this done without the funds, I'd start off with the stock injectors and an rrfpr and stock boost. have fun with that till youcan get a standalone to take care of some larger injectors. I havent been following the MAF thread, but I don't think that will run 440's either.

Christian
 
#15 ·
so

Well, I could use the stock bottom end for now and then when it dies- rebuild it nice and strong.

So what about:

The 5m has a knock sensor on the block correct? The 7m has 2 knock sensors, Im sure that would have to be swapped but would be easy. What other sensors...?

How about thigns like the 7m water pump and ac compressor- would they work fine or would there be some customization involved? I can just take the oil pan and pump off the 5m and use that on the 7m block as someone told me I could do.

Thanks
 
#16 ·
You can use the 7m water pump. In fact, I think you have to, as their different part #'s from 5m pumps. The AC is a little tricker. If you use the 7m ac compressor, you'll need to custom make some ac lines (just the ends) because they use a different line fitting than the mk2. The 5m compressor will fit, but the pulley is not quite right for the 7m crank pulley.
Read the 7m conversion links in the FAQ. It should answer most of your q's. I don't know about he KS. I would imagine the 5m KS screws into the 7m block no prob. You'll just have to use one instead of two like on the 7m's.

Christian
 
#17 ·
great

Excellent- Looks like I got all the angles covered now and now I just have to find the perfect mk2 for the base car :)

[Edit] One last thing- The alternator- its mounted in a different place on the 5m block, Will it bolt up to the 7m block in the same location? Does the 7m block have the mounts for the alternator?

Thanks for all the help answering my questions-

Chris
 
#18 ·
anyone?

Anyone? Will the alternator bolt up? Or how will I hook it up?

And for fuel (on stock boost for the time being) a RRFPR and Walbro pump will be enough on stock injectors until I get an AFC and 295's right? how much boost will the 295's support? I know that the stock 440's on mk3's will only support up to 12-13psi on the stock turbo, wouldnt the 295's support less than that? I see that many 5m-gte's run 295's and 10-11-12psi boost though... baffeling

Thanks
Chris
 
#19 ·
The 7M is a 3L so it will require a little more fuel.

My AFC is correcting a MAX of +25% with my AFM tightened 12 teeth running 11psi. I would think that the 295's would support more but that is just a feeling. I have no idea how to monitor my injector duty cycle or I would. That would shed allot of light on this issue.
 
#20 ·
the plan

Ok so here is my plan- (will it all work is the question...)

5m-GE Head : Rebuild + Port + Polish (while I'm at it) + Resurface for MHG - $500 give or take

7m-GTE Block : Rebuild w/custom 7m Low compression pistons with 5m valve reliefs (will piston manufacturers do this?) ~8.5:1 compression. - $1k or so

2mm MHG + ARP Studs - $??

7m-GTE Turbo + Manifold

7m Intercooler (Spearco IC later on) + Custom Hard-Pipes

Cartech RRFPR - $260

Walbro Pump - $105

7m-GE SPEC Stage 3 Clutch - $360

W58 Rebuild (anyway to make it stronger?) - $??

Custom Downpipe and Exhaust Set-Up - $cheap

-----After Initial Build Up-----

Megasquirt ECU

440-550cc Injectors

Turbo Rebuild 60-1 CT-26


Chris
 
#22 ·
To answer 1 question that did not get answered.

Knock sensors on 5M's. It will VARY between the different year motors, so you will need to verify the year of your motor.

82 + 83 motors. NO knock sensor.

84 motor. NO knock sensor, but there is a mounting location on the side of the block when you can install a knock sensor.

85 + 86 motors. 1 knock sensor.
 
#24 ·
Get a 85+ ECU. 84 ECU will not recognize a knock sensor.
 
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