7mge inefficiencies
 

after doing some research i still remain puzzled. what about the 7mge makes it so hard to get power out of? (except for that it doesnt have a turbo;)
Is it the intake manifold or head design? would a front facing intake manifold help? The reason i ask is because im in the beginning stages of a rebuild and i would like to gain around 50 hp if possible... i"ve read that it is harder that it looks.

Any help or mod suggestions will be greatly appreciated:)

as they say, no replacement for displacement. being a 3 liter engine only so much you can gain from non turbo mods. increasing your compression is about the only way you can go if your not adding a turbo. this can be done by using a stroker kit, shaving your head, using a thinner headgasket, boring the block or by shaving the top of the block, or a combo of all the above, but there not cheap. headers and cold air helps aswell. cam upgrades, bigger injectors, bigger throttle body openning or going to ITB, whatever gets more air and fuel in the cylender.

yeah i had those mods in mind... im wondering which is the most cost effective.. i already have a higher flowing exhaust and CAI

I think with that stroker kit and cams and header and exhaust u should be close to 300hp or pass it that's how the muscle cars did it my dad has a 69 Chevelle with 700hp and it's all motor now with a supercharger pushing over 1000hp

should be but remember that hp gains in n/a motors is greater the larger the motor.

I know but still the Lexus si350 has a 3.5 motor with 350hp

the lexus motor is alot newer, and as such uses the new twin injection system, and vvt-i. its also 11.8:1 compression vs the 7m at 9.6:1

7mge is 9.1:1
7mgte is 8.6:1

opps!:frown::frown::frown::frown::frown:

A chevy 350 is 5.7L almost double that of the 7m and a 454 is 7.4L. Plus there are tons of aftermarket mods for chevys while a 7mge has far far fewer. And by the time you put in a stroker kit and cams to build a high strung 7mge you could of bought a JDM 2jzge and left it stock with far better reliability and more hp and torque.

i thought about doing something like that but what are the mods do you have to do to get the 2jz in the MK3?

its the same as swapping the 1jz in. the 1jz and 2jz are the same block (more or less) do a search details are on here

thank you will definitely do that. just was trying to take easy way out and hoping someone would post a link lol.

so will raising the CR to about 10:1 or 10.5 really give me much of a hp gain? or will a ported head result in a larger power increase?

The only replacement for cu.in. is technology really. That's the main reason the turbo has an advantage. The 7M is a pretty old engine (remarkable how well they stand up though). I look at headache + cost + end gains when I research this area. To my knowledge, the least headache and most cost effective way is to get a 1JZ swap (providing you have everything needed before you begin). So many people talk so much about it on the forums that I sometimes get complacent and assume its easy just becuase it is such a common topic. But mapping it out you find there is a ton of "little things" to know before going in.. and I always find one more little thing.

I have never owned a more expensive car to fix properly.. lol. but.. then again.. im being fussy and usually end up buying "near perfect" or new parts only.

bumping up compression will give you id say about 15-20 hp if lucky, and not at the wheels. u have to get into the 12-12.5 range to see some real gains, and then you stress your entire motor. rings, bearings, valve train. ud wanna look at upgrading rods (not a bad mod neway) and have custom pistons made.

PnP the cylinder head is a fairly easy venture, its just time consuming. i spent 12 hours just on the bowls and short side radiuses. i didnt get crazy on the ports much but cleaned up alot of casting flash and tapered the guides. if you look at flow charts a full "street port" give you a bump in flow from 179cfm@ .30 lift to 201@ .30 lift. mine flowed 198 (+/- 1 cfm on all ports) at .30 and 28". overall i spent about 24-26 hours of straight work on mine, not including valve polishing and lapping. plus i have the stage 2 cams to put in now so those numbers could change.

im hoping to crack the 200 mark with this setup on my GE, b4 i get my sc on there.

bored/honed/decked block (50mm over, .010 removed)
PnP head, resurfaced (.008 removed)
BC stage 2 cams, 268's
adj. cam gears
comp valve springs
NPR pistons, rings (50mm over) balanced (+/- .5 grams)
king main bearings, std size
micro polished crank, std size, balanced (zero balance)
eagle H beam rods, balanced (+/- 1 gram)
ATI super damper
SDS EFI engine management system

mind you this will be in an 87 4x4 pickup with 32" tires.

after the supercharger, depending on pulley, i should be able to hit anywhere from 240-low 300s.

ill post dyno #'s for both n/a and SC form, but it will be a few more months still its done.

BTW, those stroker kits are garbage IMO, i have looked and looked, talked to lots of supra guys, and so far i havent found one thats ran or still running. the 7m motors are stroked 5ms and its pretty well maxed out. lots of custom machining needed. all for maybe 40 hp over stock, so on a proper rebuild, a scant 220-240 if very lucky. thro in the parts that ive invested in, and you might get 260-270, and about 10k spent (stroker is over 3k alone) for something that has the likely hood to fail due to stressed components.