elballoonrat

hello, my names Tim O'Donnell, i am a Mk1 MR2 guy but need info on solving knock problems in my motor, i am running 8:5:1 81.5mm ceramic coated pistons with 20mm rods, they handle the power fine, but am woundering if upping to 10:5:1 would be to much for my ecu, im running a stock 4agze ecu that handles 15psi, i am lookin gto max out at 20psi

since hondas are know for high comp i am woundering how people have solved the knock problem with out changing their ecu(water injection is the direction i plan to go)

also, if anyones interested in short shifters for cheap i can make a truly custom short shifter from your stock assembly, i sell mr2 short shifter assemblies for $50(on a exchange program only), if anyone is interested please email me, i need some info on how the honda linkages work, are they cable or direct linkage?

inspyral

Most boosted Hondas don't run c/r's higher than about 10:1. There are boosted stock ITRs, but they typically only run about 7-8lbs of boost with their 10.6:1 c/r. There are Hondas that run higher boost levels on 10:1 c/r, but that's with a lot of tuning, and standalone engine management. Pretty much all Hondas that run higher boost levels switch to a standalone ECM like Hondata, AEM EMS, etc. I'm not familiar with the availability of standalone units for the 4AGZE, but I'm sure there must be some available, since it's a popular platform. I'd wager the A'PEXi Power FC probably has an application for you. Standalone units are pretty much a prerequisite if you're trying to run high boost on a Honda, but your ECM was designed with boost tables from the factory, so I don't know if it's necessary for you to swap it out. Water injection is an effective method, but you won't find many Hondas running it. It's usually simpler to just spend some extra time tuning the fuel and timing maps.

elballoonrat

unfortunately their are no after market ecu's for 4agze's in existence(even in japan), this has left mk1 mr2 peeps to become very creative in making rear engined rockets that kick ferrari's ass for under $10,000. all though electromotives tec3 ecu which is distributurless is the gem of my eye right now, i will have to custom instal it and cnc some brackets for the crank trigger but it will be worth it when i get $1200 to take that plung.

i think i will probably go water injection then with water sprayers on my intercooler

does anyone have water injection, if so can i use a alcohol solution to increase the evaporation rate

dose anyone on the board have a 10-15psi car?

inspyral

I'm only maxing out at 10lbs of boost right now on stock internals. Are you looking at one of the Aquamist kits? Those seem to be the most common. I've heard you can inject pure methanol, which will also boost your octane rating in addition to the cooling benefits.