I have a 91 STD hatchback that only had 70hp and I did the MPFI swap, got a cold air intake that I'm using as a short ram, and put on a 2.5" stainless steel thermal cat-back exhaust. I'm not sure what the horsepower or torque is now, so if anyone has an idea what it should be, please tell me. I also have 17x7.5" rims and subs, which probably don't help with speed.

Anyway, I've been told that the car is getting more air now when I go full throttle, but there isn't enough fuel being supplied to make it accelerate as quick as it should. Not because of any problems with the swap, just because of the setup with the larger intake and exhaust I guess. Is this true, and is there anything I should do now to make it any quicker?

 

Most honda ecus run slightly rich up top stock. Adding intake/exhaust usually isnt enough to cause a lean condition. Which isnt to say its making max power, but i wouldnt worry about it.

 

Adding an intake doesnt allow more air to enter, it simply makes it easier. Unless you increase displacement its still the same ammount of air per cylinder.

 

It definatly does allow more air to enter. But, not much like i said.

Imagine putting an intake tube on your honda that was the size of a straw.
You can see how the engine wont be sucking in as much air.

 

Air to Fuel ratio...
Two options:
1. Buy a A/F gauge....Summit, Jegs etc. A $40 gauge will give you a ballpark and help you with your tuning. You don't even need to leave it hooked up once your done tuning if you don't like it

2. Dyno time with a wideband o2 sniffer. This can run from $40 for a single run to $200/hr depending on where you are.


$32 Gauge here: http://www.jegs.com/cgi-bin/nc...r=361

 

intakes are suppose to be able to allow you to draw more air because an air box is restrictive because of those grooves and those grooves are suppose to make your car quiter, that was the purpose of the airbox being made in that way. and a intake is louder because its less restrictive and the filter is not in a box, its open. hence that sucking sound when you blip the filter. no restriction.
so yeah an aftermarket intake does actually give you more air.

 

As mentioned, there's no need to change up ur AFR. CAI or SRI is not enough to affect. I have a CAI on my CRX w/ a B16A and I'm still running at -3% (VAFC setting) for both WOT and narrow band.

As for power wise a realistic increase with CAI is probably about 5whp and SRI possibly 2 or 3 (reason being CAI = colder air = more oxygen), BUT u gain more tq with a SRI then a CAI. Also FYI, 2.5" exhaust IMO is a bit too big for ur car. Ur losing a lot of back pressure and thus tq; I'm guessing w/ 17 " wheels pending on weight along with the lower tq ur acceleration is pretty not as great as u want it to be. Just my 0.02

 

just make sure you reset the ecu after the install... this allows the ecu to deliver the right amount of fuel needed for the amount of air you are taking in

 

hey i'm just wodering, people always say to reset the ecu when installing a new mod? i also heard that it doens't do anythign because everytime you start the car, the ecu re-caliberates itself? is this not true? only benefit of resetting an ecu is to erase any errors that was there.

 

hmmm... never heard anything like the ecu recalibrating every time you start the car... could be true though cause ive had check engine lights come on and you can turn the car off and back on and the light will go off... anyone know anything about this

 

from what i've heard the ecu doesn't have any internal memory for stuff like fuel maps and timing. Everything is based on varibles given to the ecu by the sensors, because if the ecu did store fuel maps and and timing you could thoeroricaly(sp?) run without some sensors until a variable changed.
Only memory in the ECU is ROM Read Only Memory.. When they came out with OBD-1 that when it stores Fault Codes, again i still don't think it has memory for anything else