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Discussion Starter · #1 ·
I was offered everything to make a NA-T 7M. the questions is, is na-t better than just going with a gte? most gte motors I have seen for sale are trashed and need to be rebuilt. I may end up paying the same price building a nat with a fresh ge than rebuilding a gte. I would like some in put from my supra folks. and what would you recommend
 

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Old 7M-GE's tend to have cleaner/tighter bearings and cranks than GTE's because they lack the stupid bypass oil cooler thing that robs oil pressure and oil flow.

Otherwise they're all tired old engines, and success with any turbocharged 7M regardless of origin is in good maintenance/prep and a good engine management solution for the desired HP level. With a full swap to GTE electronics and fuel a 7M-GE runs pretty well with a basic CT26 or 57 trim CT26.
But the higher compression, mediocre knock sensors, and inconsistent ignition timing drift that's inherent to the GTE's factory CPS & ECU design all make it a low-boost sort of game if you want any sort of reliability.

If one was starting from scratch entirely and shooting for the moon with forged internals, big turbo, modern EMS with a cam and crank sensor and a brand new wiring harness to match, etc - a GE block would be a good basis because it naturally eliminates the oil squirters and the GTE's oil filter housing/bypass garbage and all that stuff. A quality oil cooler is a damn good idea too. The oil squirters trade oil pressure and elevated oil temps for the sake of maybe preventing detonation.
With a modern ECU with good tuning I don't see the point of oil squirters for 99%+ of builds personally.
 

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I would do what Wreckless said. You can swap in a 7MGTE and possibly have a failure in the future, or you can take time to curate the parts you need for a bulletproof NA-T build that can last a lifetime. A lot of owners are really eager to just get it on the road and then wonder why their head gasket is blown. :coffee:
 

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Discussion Starter · #5 ·
Old 7M-GE's tend to have cleaner/tighter bearings and cranks than GTE's because they lack the stupid bypass oil cooler thing that robs oil pressure and oil flow.

Otherwise they're all tired old engines, and success with any turbocharged 7M regardless of origin is in good maintenance/prep and a good engine management solution for the desired HP level. With a full swap to GTE electronics and fuel a 7M-GE runs pretty well with a basic CT26 or 57 trim CT26.
But the higher compression, mediocre knock sensors, and inconsistent ignition timing drift that's inherent to the GTE's factory CPS & ECU design all make it a low-boost sort of game if you want any sort of reliability.

If one was starting from scratch entirely and shooting for the moon with forged internals, big turbo, modern EMS with a cam and crank sensor and a brand new wiring harness to match, etc - a GE block would be a good basis because it naturally eliminates the oil squirters and the GTE's oil filter housing/bypass garbage and all that stuff. A quality oil cooler is a damn good idea too. The oil squirters trade oil pressure and elevated oil temps for the sake of maybe preventing detonation.
With a modern ECU with good tuning I don't see the point of oil squirters for 99%+ of builds personally.
wow I had no idea. i would be using the stock CT26. I always wondered if I needed to tap the block for oil lines and such. since I don't am I just adding a oil cooler, I can just mount that on or behind the intercooler. as for the electronics, I am thinking it would be stock ecu something aftermarket i can afford. EMS get expensive lol. so in other words NA-T would be the way to go if I wanted to go turbo. i am honestly thinking about it .. power goals are 300hp to 350 nothing major and a W58 transmission swap I have already done.
 

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Discussion Starter · #6 ·
I built my engine on a GE block. Only thing I had to do was machine the second knock sensor where it is on the GTE block. Idr any other major changes. If you get a GE and want to go na-t I have an 88' yellow plug ecu and turbo setup. Hell I even have GTE rods and pistons that are good, I went forged.
i will keep that in mind !!
 

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Discussion Starter · #7 ·
I would do what Wreckless said. You can swap in a 7MGTE and possibly have a failure in the future, or you can take time to curate the parts you need for a bulletproof NA-T build that can last a lifetime. A lot of owners are really eager to just get it on the road and then wonder why their head gasket is blown. :coffee:
that's right. I have learned that is why it takes so long for people to build turbo cars... they save the money for the labor and source parts piece by piece, within 5 to 10 years time you will be able to afford to get the job done. I am in no rush to do this.. after the stolen crankshaft issue the build is underway.. so I will have a fresh stock GE built that I can put in storage and just round up all my parts .. in the mean time hopefully I will have one car that I can enjoy in stock form. and save my money. like I said I am not looking for major tire shredding horsepower numbers. I am looking for that back road mountain twisties kinda speed. That early Sunday morning spirit drive.
 

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Discussion Starter · #10 ·
Whatever you do, use an MLS head gasket. The composite stock one will fail and tear up your head and deck at the same time.
oh heck yes! i am glad you mentioned that, i was going to ask if the head and block is mechined to stock spec. does it need to be redone for a MHG ?
 

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@Chocolate Cowboy An MLS gasket requires a finish quite a bit smoother than what Toyota did originally. I just ran through that process. I have no information about how flat the deck needs to be for an MLS gasket, but I suspect the TSRM spec of 0.002" over the length is sufficient. Interestingly, the TSRM merely says if the deck is not flat within 0.002", you need replace the whole block, and says nothing about remachining the deck.
Other peeps on this forum have more experience than I have.
 

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If the head and block are decked by a machine shop, and the result is smooth enough that it feels smooth and snag-free if you drag a fingernail over it, chances are very high that it'll be just fine for an MLS headgasket.

The biggest thing is that you need to be mindful of your desired final compression ratio. Decking the block and head will remove some material, and MLS gaskets are available in a variety of thicknesses to suit different machine work/desired compression ratios. For a simple build to run 7M-GTE electronics aiming for a responsive ~300whp on pump gas, I'd aim for around 9.0:1.


Edit: Also, I changed the thread title to make more sense. 🍺
 

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If the head and block are decked by a machine shop, and the result is smooth enough that it feels smooth and snag-free if you drag a fingernail over it, chances are very high that it'll be just fine for an MLS headgasket.

The biggest thing is that you need to be mindful of your desired final compression ratio. Decking the block and head will remove some material, and MLS gaskets are available in a variety of thicknesses to suit different machine work/desired compression ratios. For a simple build to run 7M-GTE electronics aiming for a responsive ~300whp on pump gas, I'd aim for around 9.0:1.


Edit: Also, I changed the thread title to make more sense. 🍺
So its fine to run 9:1 pistons on a streeet car build with stock ecu on a turbo motor?
 

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So its fine to run 9:1 pistons on a streeet car build with stock ecu on a turbo motor?
Yes, just run the best pump premium available, and don't get stupid with your boost levels. Make sure you set your base timing at the CPS correctly at 10* BTDC with T1 and TE1 jumped.

Basic FMIC/Downpipe/Exhaust with a stock CT26 and stock injectors etc at 10-11psi should net you 260-280whp. If you keep the NA's W58 and 4.30:1 rear gearing, it'll be a perfect match for a set of lightweight 17x9's wearing sticky 255's or 275's all around, and a good set of coilovers to make the canyon carver you're looking for :)
 

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Discussion Starter · #17 ·
Yes, just run the best pump premium available, and don't get stupid with your boost levels. Make sure you set your base timing at the CPS correctly at 10* BTDC with T1 and TE1 jumped.

Basic FMIC/Downpipe/Exhaust with a stock CT26 and stock injectors etc at 10-11psi should net you 260-280whp. If you keep the NA's W58 and 4.30:1 rear gearing, it'll be a perfect match for a set of lightweight 17x9's wearing sticky 255's or 275's all around, and a good set of coilovers to make the canyon carver you're looking for :)
That’s exactly what I want !!! That’s it right there!
 

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Discussion Starter · #18 ·
here is a stupid question, to get 9:1 compression do you change out the pistons, or its that compressing created from the space that's made using the metal head gasket? just wondering...
 

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here is a stupid question, to get 9:1 compression do you change out the pistons, or its that compressing created from the space that's made using the metal head gasket? just wondering...
Hardly stupid - informed question, actually 🍺

A factory 7M-GTE is about 8.5:1 in 100% stock configuration
A factory 7M-GE is about 9.1:1 in 100% stock configuration.

Assuming we're starting with a GE motor, pistons and all, just adjust to get about stock compression with a MLS headgasket after you do the rebuild. If you mix up parts with GTE pistons, etc, make sure to include that in your math for selecting a HG thickness based on how much you have the head and block cut to clean them up.
 
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Discussion Starter · #20 ·
Hardly stupid - informed question, actually 🍺

A factory 7M-GTE is about 8.5:1 in 100% stock configuration
A factory 7M-GE is about 9.1:1 in 100% stock configuration.

Assuming we're starting with a GE motor, pistons and all, just adjust to get about stock compression with a MLS headgasket after you do the rebuild. If you mix up parts with GTE pistons, etc, make sure to include that in your math for selecting a HG thickness based on how much you have the head and block cut to clean them up.
ohh i was thinking i can use the ge pistons
 
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