Dontoh

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?

blue94delsol

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

94EG8

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.

Dontoh

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

blue94delsol

u COULD blow up the motor

Dontoh

from it running to lean and ****?

94EG8

No.

Yes.

thumper64

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".

EdSales

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.

Dontoh

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?

94EG8

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.

Dontoh

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

94EG8

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

Dontoh

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

94EG8

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.

Dontoh

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

94EG8

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.

blue94delsol

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

Dontoh

that was so informative, thanks



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

94EG8

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