k so im running a gsr head on a b20 block with a gsr tranny, long story short, its running on a p28 ecu, head is marked p72.. would this cause anything? or would i lose out on anything even?

 

get the p28 chipped and run a base map of the parts you have used to build the motor.



http://www.phearable.net/tech/enginebi.html

http://www.phearable.net/tech/efibeginnerguide.html

 

Get the P28 chipped, throw a basemap on it and drive it straight to your local tuning shop and have it dyno tuned. Running on unknown maps is just asking for trouble.

 

alright sounds good. would running the wrong ecu cause vtec to not engage without throwing a cel?

 

u COULD blow up the motor

 

from it running to lean and ****?

 

No.

Yes.

 

chip the P28, get it tuned. Their map will end up being somewhat like a GSR scaled up to 2 liters. The geometry will slightly alter what it needs. Longer stroke means more piston dwell at TDC and tons of other junk that pretty much just means "get it tuned".

 

Your question should be more like, what Tuning Program should I get. Running that motor on a Stock ECU or even a Basemap, and your just waiting for it to pop. Getting a tune can be costly, but so can replacing a motor, and its not a matter of if it will blow, its when.

 

i'm not running the motor with a stock ecu. the car is being torn apart and the engine done up with new parts. i saw that the ecu was a p28 so i asked if it was even the right one

how do i go about chipping the ecu? i just buy a chip? or have it sent in to be programmed or wha?

 

You have to socket the ECU, which involves soldering on a 28 pin socket for the eprom chip as well as a few other misc components. Then you install a chip with a basemap for your setup, then drive to your tuner and have it tuned.

 

the fak, i just cant pick up a p72 and have that tuned?

 

Same thing, you'll have to socket it first.

 

but it'll be cheaper than workin with the p28 wouldnt it?

 

No. you already own a P28 right? The cost of chipping either ECU is going to be the same. So I don't see the point of buying a P72 and then chipping and tuning that.

 

i think im misunderstanding something, why cant i just plug and play a p72?

 

P72 ia for a GS-R engine, you don't have a GS-R engine, what you have is hybrid. If you run a P72 its going to run lean, it will blow up eventually. Since there is no factory ECU for your application your best option is to chip and tune an OBD1 ECU.

 

sure just go run the p72 and see how the car runs and for how long

 

that was so informative, thanks



i think the question i shoulda asked is, what is the difference between chipping and tuning?

 

chipping is basically socketing the ECU and installing the chip. Tuning is the act of tweaking air fuel ratios, timing, vtec crossover etc.