SO I guess im out of time. Iv stalled, Iv lally gaged, Iv faked sickness and famine, I have to rebuild the girlfriends Montero or she may litterally kill me.

Little does she know, its a christmass gift she has no idea about. I put the parts list together Im going to rebuild and upgrade the suspension, Brakes, Cooling, Engine internals, and umm, cough, hmm, himf, pft, Performance?

Im a long time shade tree mechanic that loves to put motors where they dont belong but trying to figure out how to get extra power out of a monty is mind boggling.

The 3.5L is pumping out 200hp/230tq the car weighs 4600lbs thats a power to weight ratio of 23/1 1hp for every 23lbs of metal your moving, not exactly exciting. So.... I decided I would look around and see if I can get some extra hp out of the car for her while I was rebuilding the engine.

My search turned up exactly squat. Maybe less then squat compared to what the following is on my normal projects. Short of plumbing a universal nitrous kit in or a custom turbo or supercharger kit there is no way to possibly see numbers in the 300hp range. So...

I figure Ill use every cheat in the engine building book.

Ill try this.....

Over size the pistons by .020
Port match everything on the intake and exhoust side
De bur and polish the runner on the head and intake
Balance the rotating assemblie
Switch her to synthetic oil after the break in period
Use a piggy back fuel computer to compensate for the added displacment and flow
Injen intake
Magnaflow catalytic converts

This may actually increase her gas milage since she wont have to be as rough on teh accelerator. Im hoping this will pick up HP and TQ atleast 20-30 hp/tq each at the wheels.

This is all I can literally do. I cant seem to find anything else in the range of performance for her car.

She is also going to get some ceramics in the brakes and some tokico treckmaster shocks. As well as new tie rods and bushings. I cant wait to get this SUV back into action. I hope the added performance will make it a better tow vehicle for next summer.

If any of this is a bad idea becouse the cylinder walls are thin or im going to have a pain over riding the factory fuel maps etc please warn me. Thats why I posted this was to get input from you guys.

Thanks
Alex R.

Operation Dakar Dreams!

 

I have no way to know this specifically for a 6G74 in a Montero but based on my general experience tuning Japanese vehicles I doubt if you'll need any fuel curve remapping just for a port/polish and the intake/exhaust mods you listed. The increase in air flow through the engine probably won't be enough to lean out the O.E. fuel map.

 

Does anyone know if I can opunch the sylinders bigger then .020 over? How big can I go before im going to ahve to alter the fuel maps?

Thanks
Alex R.
Ramirez Racing

 

i have a new head gasket set for your motor

 

Forged crank from the 3.8 drops right in, bores can safely go 2mm over (!!!), stock non-Mivec 3.8 heads flow 18% more air than ported and polished stock 3.5s, use your original rods because they are forged. You will need custom pistons and to select cams, but this leaves you with a 4.1L, simple, naturally aspirated motor with numbers in the 300 range. This is something some of the Aussie racers are doing, check their forums.

 

100% correct

 

O wouldn't e an bother with .020" oversize. That is barely within wear anyway range. I had my engine 4enuolt after pidton failure. Machinist oversized the bored to 0.050. You will need custom pistons to maintain compression ratio for increased bore size. They do make a matched set of rows/pistons for 0.050, but I doubt they'll have it for larger oversize. You'll have to put together your own set if you can find it.
Mitsubishi internals are very strong. I wonder if going in a direction of small turbo is a better option? You can do an electric super charger. That should ease up exhaust plumbing.
For thst matter, you can start here: https://www.racetep.com/automaker/starion/montero/monturbo-html.html