7m Na-t vs 7mgte ?

[1986.5supra_kid]

great tread. im on same page as 7matt-ge. i got plans for getting boost controller and fuel controller, and upgrade fuel system, then i just need hard pipes for turbo in intercooler, and i belive seein bolt in side of oil pan (oil return from turbo?) and the oil supply is no sweat, same for gettin water to it(no prob) using electric fans also. and ngk iridiums. hoping to run on 87 octane in a pinch but regularly using high test.

 

[shaeff]

I wouldn't risk running 87 octane in it. 7MGTE's use 93, (though you can get away with less, but I would not) and your motor will have a higher static compression ratio when off boost. I'd run nothing but 93 in it. One of the main things you need to be worried about is detonation with a 9:1 CR turbo 7M. Running 87 will put you right in that danger zone even with moderately low boost. You'll fry that motor quickly.

 

[ValgeKotkas]

Does someone know whether the turbo pistons are built stronger than the N/A ones (they do have to run more power...?) or are they basically the same minus the compression difference?

 

[shaeff]

In this case it's less a matter of physical strength, more a matter of having a good tune. Hell, stock pistons (both N/A and Turbo) can support 500rwhp, which has been done many times. (and often times more than that- like x-man's stock motor pushing 700+rwhp) But if you detonate you can kiss your motor goodbye. A proper, SAFE tune is the key here. Neglect that and no matter how well you built that motor, it'll end up in the scrap pile.

 

[1986.5supra_kid]

still with correct tuning and low boost i do run risk, but a low risk. anyways not the question i was quite after. I have seached the threads for a successful ge turbo with ge electronics. but i would do away with the ignition system and get msd ignition system. be honest i have only boosted a small block with carb. im just taking same route. (more fuel, more air,better cooling)(ignitiion,fuel delivery,timing inconsideration and low boost levels) in the small block i strictly use high test.

this was a lil off topic but it was just for a backround.
"Thanks for input Shaeff"

 

[shaeff]

In all honesty, I wouldn't waste your time trying to use the GE electronics. The GTE setup will make it much, much easier to pull off, and with a larger safety margin to boot. Running a 9:1 CR 7MGTE even on low boost you're going to want to run 93 octane.

Running the GTE electronics puts a fuel cut in there to prevent you from melting pistons, meters air much more thoroughly, and the ignition system will work perfectly all the while being damn near plug and play. I've already done one of these, and it was simple using GTE electronics. I wouldn't even consider doing it any other way, even if someone offered to pay me. Too much of a headache.

Edit: Putting a better fuel pump in is also a MUST. Even at low boost your chances of running lean are increased drastically when adding positive pressure to the motor. An adjustable fuel pressure regulator isn't a bad idea either.

 

[ValgeKotkas]

Well, which pistons are "more" forgiving then?
Just that we built a 7mge-t that didn't blow(Ajusa HG) with the first 0,6 bar of boost it had but the turbocharger did... and while the turbo was renewed I got another car, turbo one, that has a stock rebuilt engine with 1.2mm mhg.
Both running MAFT-pro.
I was just thinking whether the latter one is the better choice to go, or maybe not... ( I can't keep both)

 

[7Matt-GE]

either are fine. just make sure you know the compression of both types of pistons before hand so you can use the right application

 

[ValgeKotkas]

I ain't taking the engines apart anymore.
Though probably the turbo engine will stay, I'm just thinking, theoretically.

 

[shaeff]

Well, which pistons are "more" forgiving then?
Just that we built a 7mge-t that didn't blow(Ajusa HG) with the first 0,6 bar of boost it had but the turbocharger did... and while the turbo was renewed I got another car, turbo one, that has a stock rebuilt engine with 1.2mm mhg.
Both running MAFT-pro.
I was just thinking whether the latter one is the better choice to go, or maybe not... ( I can't keep both)

Again, that all depends on power goals, though, the turbo pistons will be more forgiving simply because of the lower compression they provide. Less compression= less heat= less of a chance of detonation. If you plan to make big power, the stock GTE block will allow you to run more boost. If you're just looking for something to scoot around town in, the GE->T would be better because it has more off boost throttle response. If higher power is your goal, I'd stick with the GTE block simply because you can run more boost and make more power safely out of it.

either are fine. just make sure you know the compression of both types of pistons before hand so you can use the right application

Application is key. And I will keep saying as well, that a good tune goes a LONG way.

 

[7Matt-GE]

GODLY TUNEZ make sure you have one. Lots o gas lots o air.


http://cgi.ebay.com/ebaymotors/86-8...r_Truck_Parts_Accessories&hash=item5889c65d7b <----------- mmmm i might get this turbo kit.

 

[fitmk3]

Shaeff, If I have an 87 N/A that mean mine doesn't have oil squirters or return feed line holes, But would an 87 Turbo motor lack the same things? Could I just get the driftmotion Turbo and intercooler kit, a long with new GTE electronics and a new MHG and Pistons, Rods, Valve train, Boost controller, AFRP, Fidanza adjustable Cams, get it tuned and put down some pretty decent power? or Should i Just redo the fuel system with larger injectors and SS lines and what not? Also, would a AEM EMS take place of all the neccesary GTE electronics? Sorry for the newb questions, i'm quite new to cars and such.

 

[7Matt-GE]

Shaeff, If I have an 87 N/A that mean mine doesn't have oil squirters or return feed line holes, But would an 87 Turbo motor lack the same things? Could I just get the driftmotion Turbo and intercooler kit, a long with new GTE electronics and a new MHG and Pistons, Rods, Valve train, Boost controller, AFRP, Fidanza adjustable Cams, get it tuned and put down some pretty decent power? or Should i Just redo the fuel system with larger injectors and SS lines and what not? Also, would a AEM EMS take place of all the neccesary GTE electronics? Sorry for the newb questions, i'm quite new to cars and such.

not sure about the feed lines BUT if you look up the thread a bit. he said that the 87s never had squirters to begin with

 

[1986.5supra_kid]

Shaeff,
Reason i wanted to keep ge electronics is because i had butchering other supras(turbo), not many left. at least in my area. if i found a local with rod knock or just wrecked then yeah i'd do the swap.

 

[shaeff]

Shaeff, If I have an 87 N/A that mean mine doesn't have oil squirters or return feed line holes, But would an 87 Turbo motor lack the same things? Could I just get the driftmotion Turbo and intercooler kit, a long with new GTE electronics and a new MHG and Pistons, Rods, Valve train, Boost controller, AFRP, Fidanza adjustable Cams, get it tuned and put down some pretty decent power? or Should i Just redo the fuel system with larger injectors and SS lines and what not? Also, would a AEM EMS take place of all the neccesary GTE electronics? Sorry for the newb questions, i'm quite new to cars and such.

No oil squirters ever on the N/A blocks, oil squirters should be in every North American GTE block. Early JDM blocks didn't have them, but they were added in late '89 or '90 I believe.

What are your power goals, those are two radically different options, and regarding the AEM, that's a full standalone computer that completely eliminates stock ECU. You'd still use the GTE electronics unless you wanted to convert to other stuff.

Shaeff,
Reason i wanted to keep ge electronics is because i had butchering other supras(turbo), not many left. at least in my area. if i found a local with rod knock or just wrecked then yeah i'd do the swap.

Gotcha. Even so, you can find wiring harnesses and ECUs, and most of the other stuff easily here in the FS section. But hey, work with what you've got, just be careful!

 

[fitmk3]

My power goals are 350~450 I know that's a huge difference. But anywhere in there i'll be plenty happy! haha. If I were to just turbo my current GE how would I run or set up the oil feed and return line's for the turbo? Will all the CPS and stuff like that bolt up to a non turbo engine? Should I just get A gte and do the swap?

 

[mecevans]

Im looking into water/meth injection pre turbo. I've seen a couple boost pressure controled ones that are really simple.

 

[themadhatter]

Everyone does relize that its not that much trouble to get a machine shop to add oil squirters to your 7m right ,its just an added expense and like all motors the tune is the key to a long and happy life thats why i suggest megasquirt becuase the factory ecu is so limiting on your safty margins.

 

[shaeff]

Not everyone wants a standalone though. For a modest 400hp the stock ECU will do fine. And most of these guys aren't rebuilding their motors which means no machine work for the most part (save for lapping the head) If they were rebuilding and wanted a higher CR they should just grab a GTE block and build it with N/A pistons. More benefits to that are oil squirters, two knock sensor locations pre-drilled, drilled for turbo oil feed etc...

 

[mecevans]

I started. My na-t last week. Have not run into any issues yet.