im getting a ls/vtec longblock, no ecu, its a ls block with gsr head. its OBD1, i'm putting it in a 99 si, (so i think its a P30 ecu?? right??) i need to know if i should put the ls/vtec to OBD2, or should i find a p28 ecu, or a different ECU or what i should do. i would like to tune it, if that changes the question at all. Thnk you

 

Actually, the em1 ecu is labeled P2T, and is obd2B
P30 was in the del sol vtec (obd1 and obd2A)

You might be able to get away with running the stock em1 ecu...Im not sure how the gsr intake manifold's 2ndary butterfly would like that, but maybe someone else does...

What you go with, is really up to you. A chipped p28 or a stock p30 would work just fine, but if you want to be tuning it with something other than afc hacks (ie hondata, crome, uberdata) you definately want to be obd1.
(And in that case, good luck finding an obd1 p30)

 

If you're going to mod it and tune it/convert to obd1, I would stick with the obd1 p28. It's easy to tune and can be found easily.

Or like pdiggity said, you should be able to get away with the p30 or even the p72 gsr ecu once you're gone vtec provided you've used a b16 head.

 

hows the car going to like being obd1, like will it throw codes? or what not? can i run a stock p28 ecu, or do i need to run hondata or uberdata or crome, or will a VAFC2 work?

 

The car doesnt give two *****...it doesnt even know...
The only thing that knows that it is obd1, is the ecu itself - which runs the way it does because it was programmed to do so.

(no, there will be no codes)

Because of the demands of the dohc, however, you would need to have a p28 remapped with the correct curves. Stock, it just wouldnt run the right way...

 

^^ the harness is what acts more obd1 going into the computer, it just uses the sensors that an obd1 ecu uses.

obd1 has less and less finicky sensors than obd2 generally among hondas.

 

what should i use to chip it/program it?

 

Since its wisconsin, I'd say just go obd1 with a P28. If you want to get it tuned, call up Extreme motorsports, they're in Racine and ask for Mike ('bearsEK' on HT). He'll hook you up with Hondata s200 and a dyno tune, as well as part-throttle tuning. If you want to save a couple bills, I could do a street tune with CromePro on a p28 & a wideband o2, then you could dyno it at Extreme and they'll be able to tell if it needs a bit more/less timing.