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Sounds like an interesting project.

From a pragmatic standpoint for the $$ you're going to put into that you could probably drop in a 7M-GTE and make more power reliably.

Just my $0.02.
 

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Even a bone-stock 7M-GE can manage 200hp at the crank... seems like a much cheapier and easier way to acheive that particular goal! Or if you're a little more adventurous, a 2JZ-GE is rated at 230hp and can be picked up fairly cheaply.

Still, it's fun to experiment with stuff. :)
 

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If you calculate fuel savings $$, you are going to have to drive a LOT to come out even. I considered the 5M upgrade at length. It sounds interesting, but for max power and factory reliability, it is hard to beat the 7MGTE. Mine should be done in two weeks, so I am a bit biased. I wanted 300HP and could care less about mileage, even though it should deliver 25+mpg on the road. The car is a Toy for me, doubt I will burn more than 300 gals per year. Even at todays prices, it is less than $600 total. I can't see spending a lot of money on the 5M to save fuel, it will never have the power and upgradability of the 7MGTE.

Different strokes and pressures for different folks.
 

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DriftMe said:
To Improve Cooling Efficiency
* An increased efficiency/surface area, aftermarket, radiator
* A coolant mixture with decreased surface tension
** As an experiment, I want to test the effects of a solution that decreases surface tension by up to %70. This solution can be easily made in one days time, but has an effective life of 24 hours.
Does that mean you have to change the coolant every day?
 

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Interesting science project, but kind of like building milk without using the cow. It could be done, but why? :greatpos:
 

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I think it could be done. A lot of modern cars are very close to those goals already. The Quad 4 GM's for instance. My new Highlander, 160 HP 4 cyl that is getting 23 mpg in town in a heavy vehicle.

Now if you take emission control restrictions and durability out of the design criteria, it's very easy. I just don't think you are plowing any new ground using well established efficiency tricks.

A lighter car would be a huge advantage. The MKII is a slug.
 

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I think your goals could easily be attained without doing half of that stuff and for a fraction of the cost. I'm part of the way there myself infact and I have similar goals for the motor in my 85. First off, just go 6m. The extra displacment is great for gas milage as well as power and will put you very close to your power goals. As for gas milage, 30 will be very easy. I've managed 28.5 in a bone stock 85 in excellent mechancial condition. Most mk2s don't manage those numbers because they have lower compression, dirty intake ports and manifold, clogged injectors, etc etc. A freshly rebuilt head and some clean injectors should be all any 84+ mk2 needs to get 28s. Add a 3.72 diff and you've got your 30mpg easy. As for your twin intake system modeled on mazda's technology, you should look a little closer to home. The 4age engine in 85 to 87 Corrolla GTS's come with that exact same setup, Toyota calls it TVIS. I'm betting it predates teh mazda tech too. Its a neat system that is good for gas milage, and should be good for a bit more low end grunt. Practilcaly though, it has its disadvantages which is why toyota ditched it on the 4age in the 88+ GTS's. It was replaced with AVIS (Acustic Variable Intake System) which works to attain the same end product but does it with vacume canisters instead. AVIS is use on the NA &M & 2J engines, as well a couple 3sges and such. The problem with TVIS, besides that fact that the mechanism just stops working on most high milage 4ages, is that for about 1000rpm before the switch over (occurs at 4500rpm), the engine is actually starved of air as the little intake has run out of steam by that RPM. Once it opens all is good, except that the TVIS butterfly valves in the 2nd runner blocks the airflow somewhat and limits peak power. Its a common mod to remove the TVIS system on race 4ages, or to switch to the later style intake manifolds. You may also want to look into stand alone engine managment. Theres a guy with mk2 with the SDS system, otherwise bone stock, and he does something like 32mpg on the highway.
 

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30 MPG in town is the goal. Hell, a full size GM car with a 200HP 3.8 will get 30+ on the highway.
 

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I vote for swapping in a 7MGTE. Major NA mods are a waste of time IMHO. BTW you can easily run 10:1 compression on premium fuel. I run higher than that on CAs wonderful (<---- sarcasm) 91 octane with no pinging. The 200 crank hp isn't a hard goal on a NA 5M but the 30 city mpg is. For a 200 fwhp 5M check out Don Lews mod list. You're going to have to drive like a grandma to get that kind of mileage. Generally increasing performance and your mileage goes down. Your best bet for this is to use a standalone and run the engine crazy lean. And use those 2.90 rear gears like GM uses in their cars for crazy mileage. My dad's Camaro has those and I think the thing turns like 1500 RPM at 80 MPHs. BTW if you want the ultimate in intakes run an infinetly variable runner design. There are all kinds of SAE papers written on them and the optimum runner length is a fairly easy calc. Most cars these days have some sort of a multistage intake.
 

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DriftMe,

I applaud you for your enthusiasm, dedication and creativity! (I'm an engineer too!)

Here is some info I've put together over the last few years, regarding building up a 6M-GE NA allmotor setup. This has all been inspired by the great discussions that we had on the Yahoo list. Maybe it will give you a few more ideas on increasing HP (or in some cases increasing available HP by decreasing losses)... Mileage will be unknown, but most of these mods help to increase engine efficiency so they should not hurt mileage.

Building up a non-turbocharged Mk2 Supra. [numbers in square brackets are approximate gains expected from the mod as compared to the stock setup being replaced]

Rebuilt 6M [approx 190 HP stock] or 5M [approx 160 HP stock].
Port and polish the head (improves flow but also reduces compression a tiny bit). [+5 HP]
Shave head to get compression a bit higher, but not to the point of making it an interference engine if the timing belt breaks. Use 84-86 domed pistons. Try for a comp ratio of about 10:1. [+10 HP]
Headers, modified to collect into a 2.5 or 3 inch pipe, all wrapped to keep heat in. [+5 HP]
High flow 2.5 or 3 inch cat (match size to header collector). [+3 HP]
2.5 or 3 inch mandrel bent stainless steel exhaust (insulated for at least the first few feet) to a straight through muffler. [+5 HP]
Custom intake with ramair coldair intake and high flow air filter. [+10 HP]
Loosen AFM spring to richen mixture. [+2 HP]
Ported/polished AFM for now (gain a few HP) replace it with MAF sensor if possible. MAF should be good for 10-30 more HP [+2 HP]
Phenolic spacer between head and intake plenum to keep intake air cool. Should gain a few ft-lbs of torque due to longer intake air path and several HP and ft-lbs from colder air. [+5 HP]
Water bypass on throttle body to reduce intake air temps. [+2 HP]
Advance timing to 15 deg BTDC. [+5 HP]
Electric water pump (frees up 15-25 HP according to some people). [+15 HP]
Electric fan (frees up a few HP). May need upgraded alternator. [+3 HP]
Maybe some mild cams, nothing too rough. Adjustable cam gears are required with new cams. Big $$ for small gains. [+5 HP]
Coatings on chambers and piston domes to keep them cooler (if you can afford it).
Vacuum pump on the crankcase? [+5 HP]
And of course, the standard body lightening mods. I plan to get a couple hundred pounds out of the car without removing any (visible) interior parts. Lots of parts on the car that I never use or don't need.... Rear wiper washer fluid bag, broken power antenna, headlight washers, broken A/C, spare tire, rear carpet underpads, cruise, charcoal canister, etc, etc, etc. So far I've found about 200 lbs of stuff that can be removed that no one should even notice, until they race against me! 200 lbs lighter should shave 0.3 seconds from quarter mile times.

All of these mods add up to approx 80 extra HP.

Modded 5m should be putting out about 240 HP at the flywheel, 200 RWHP. 13.7 sec quarter mile.
Modded 6M should be putting out about 270 HP at the flywheel, 225 RWHP. 13.1 sec quarter mile.

Everyone, feel free to agree or disagree with anything listed here, mods or the suggested HP increases!
 

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Dean, the later style pistons come coated from the factory. At least the ones from 5ms in 88 Cressidas did for sure.
 

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Dean said:
DriftMe,



All of these mods add up to approx 80 extra HP.

Modded 5m should be putting out about 240 HP at the flywheel, 200 RWHP. 13.7 sec quarter mile.
Modded 6M should be putting out about 270 HP at the flywheel, 225 RWHP. 13.1 sec quarter mile.

Everyone, feel free to agree or disagree with anything listed here, mods or the suggested HP increases!

Okay, I'll disagree. :) Gotta say those #s are HIGHLY optimistic at best. A N/A 5m with with 240hp? High and low 13s with N/A motors?? It will never happen unless you have massive weight reduction in mind.

To the original thread starter: Sounds like a fun project if properly funded and engineered. But, at the end of thee day you would still have a 170rwhp and wanting more power, power that you will never get from a N/A motor.
 

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Ok, about all this. Wow. I just realized, that I know nothing about cars compared to you guys. When my buddy Ken (MK2Racer) referred me here, he said you guys knew your stuff. Now, I find out for myself that you guys REALLY know your stuff. As for suggestions, I don't know the half of what you all talked about, but more hp is good, and I know that much. Good luck whatever you decide to do, hope it all comes out ok. Hey, wanna rebuild my motor? :drink: Just kidding... Unless you really want to do it for free.....
 
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