n/a ka dyno run

[RideNslidE]

yesterday i ran my car at the dyno for some insight and fun. the mods i have is basically just a custom catback exhaust on 91 oct. and its a 93 manual car heres a link 2 the graph.

hp-red tq-blue afr-black

it looks like it gets rich around 3k rpms then it looks like at 5k or so it falls on its face with too much fuel.it came up with 138 tq and 137 hp to the wheels at 6500 ft altitude.

my main question is how can i clean up my afr to pick up some lost torque. i looked into the e manage or maybe a cai with a 248/232 cam swap any help would be appreciated.

looking at other dynographs for 240s it looks like my torque band is suffering. any ideas maybe just a tuneup, also i have altima injectors is there any difference to the 240s injectors? if my link dosent work for you guys let me know.
Modified by RideNslidE at 5:01 PM 3/17/2009

[B00STFED]

i/h/e/ cam swap and apexi FC

[RustspecS13]

Looks like the knock sensor is bad, as it goes into a safe timing map untill around 3000rpm and then goes to normal timing.

However you REALLY need to get it tuned, as it goes way too rich at high rpms. Alot of guys don't get their NA KAs tuned and leave alot of HP on the table. 10WHP+ easily and a good amount of response and MPG can be picked up with something like nistune.

~Alex

[del82]

First off, I'm assuming the engine isn't brand new (:

Most cars from the factory are built to run a little rich (well, OBDI cars in particular). This is supposed to be a safety feature to prolong the life of the engine, better to have all the fires lit heavy or not at all than running light and too hot. Problem is, with OBDI the fuel map won't automatically adjust over time, so when the engine gets old and starts losing compression due to blow-by and whatnot, the heavier fuel vapors and particles stay in the cylinder where the air manages to escape, along with that you're getting excess crankcase gases back into the engine, also from wear.

All of that turns into a rich graph on the dyno, I'd agree with RustspecS13 on chip tuning it first, then if it's a dual cam there's an exhaust cam trick elsewhere on this forum that looks pretty handy. Course, if the motor is all worn out, the biggest benefit you might see is probably just tearing it down, tank it, hone it and put some new rings in it, or just bore it and get new pistons/rings, but that's going to be bigger budget.

[RideNslidE]

thanks for the responses! ive looked into the daughter boards those guys who do that stuff are either really smart or have ALOT of extra time. I will look into the nistune stuff too. the reason i said e-manage over apex-i afc is i can find the greddy cheaper and i dont need v-tec adjustability... enough rambling a good tune alone is the way to make up for that lost MPG's and torques down low, right?

[RustspecS13]

Try ruling out the knock sensor before you tune around it. IDK if theres a writeup on a KADE knock sensor bypass (there should be one some where), but all it entails is finding the harness for the sensor and putting in a resistor in the connector and driving to test it. I think its a 470K resistor, or at least is for my maxima.

Search for the right way to do the by pass. That way when its installed if it feels better, its a knock sensor problem. Then get a new sensor and sub harness for it.

~Alex

[RideNslidE]

sweet ill look around and check back in the next coupe days.

[dc1984]

nistune looks like a verry good product for tuning ecus, but if you do choose to go that route, just make sure u dont plan on doing any motor swaps in the future as nistune is a stadalone. it wont be able to be swapped over to a different ecu if u do a motor swap.

but if u plan on keeping the KA, itll be perfect if u ever end up going KA-T cause youll already have a good standalone setup ready to tune.

as far as i know, probably wanna the best bang for ur buck standalone systems out there. less then 600 bucks and u got control of ur ecu and data logging capabilities of all its stock sensors, and additional ones if u so choose to add them at a later time.

good luck