Mikes 7MGE-T engine build

[mecevans]

Changing compression does not alter A/F ratio. Even if it changed the ECM can compensate through closed loop fuel control. These cars run rich stock which is safe. Leaning it out will yield more power but you loose that safety net.

I'm around 9-1 compression, 7 psi with 91 octane. 87 made it knock part throttle up hill. I could use 89 if i was just cruising on the freeway.

 

[Backlash2032]

I was just wondering if the A/F ratio was safe for higher compression without a need for a tune.

So would you say 91 octane + 10 psi on N/A compression would be safe?

 

[Devin LeBlanc]

11.5 ish, I started to knk right around 10 lbs on 91 with high compression

 

[Backlash2032]

What can be done to counter detonation?

 

[mecevans]

Lower intake temps........methanol injection.

 

[Devin LeBlanc]

Meth injection IE (Higher octane) I chose to run E85 as it has a octane rating of 108. Im planning on running 25-30 lbs on E85 with high compression. Never had any knk and advanced the ignition timing a whole hell of a lot!

 

[Backlash2032]

Would retarding the timing help with detonation?

 

[tomsupra8683]

Im running 15lbs of boost on my high compression 7mgte no problems at all,im runnig 92 octane arco gas.Under full boost the afr's is around 10.50 -11.00

 

[mecevans]

Listen to this weird noise after my engine cooled down from a long drive. I think its the timing belt tensioner . Need to do the valves anyways.

The clutch is broken in and i can highly recommend it. Its time to install an mbc an moar booooost!

[video=youtube;cbwpjOWfAn0]http://www.youtube.com/watch?feature=player_profilepage&v=cbwpjOWfAn0[/video]

 

[Devin LeBlanc]

Pull the alt belt off and see if it still does it. If so, timing belt tensioner for sure. Could be water pump as well.

 

[mecevans]

The dyno at school is fixed so ill be doing a hp/tq pull on friday!

 

[mecevans]

And there it is. WHP and torque in 4th gear.

Rebuild engine ~9.0-1 comp
GE cams
Stock ct at ~6 psi
DM DP
DM cone filter
Stock NA cat and exhaust

**Fixed the scaling.

 

[mecevans]

Corrected scale

 

[Backlash2032]

Thats impressive for stock boost, and thats a massive amount of torque..

Do you think a turbo intake cam would yield even more horsepower and torque?

 

[mecevans]

I bought some adjustable cam gears to see what i can do with the GE cam. Devin showed me a before and after dyno with the cams degreed. It was pretty impressive. I'm just waiting to hear back from him his specs.

IIRC, the turbo cam has ~1mm more lift but less duration. I dont have acess to the dyno for 2 months as the school is on break. I have a turbo cam ready if im not happy with the results. What i really need next is a 3in cat and catback, but thats out of my budget.

 

[mecevans]

The GTE vs GE cam debate has never been accurately tested. Its all been butt dyno hearsay. Proper way to do it is to degree each cam on a dyno.

 

[SURUKO]

Nice numbers, Keep it going

 

[timtiminy]

would love to hear an update of the cam comparison. I'm also looking to build my 7mgte at 9:1, what did you do to achieve this/ verify compression ratio? I'm planning on 83.5mm bore, NPR gte pistons, appropriate mhg thickness based on how much was machined off block and head.