i have a 95 gsr obd1.....i was wondering what would work better....my obd1 ecu or a chipped p28? i have intake,headers,exhaust,clutch....and my vtec pops at 4400 or 4500 with the obd1 ecu....my chipped p28 (thats wut the guy told me) vtec opens at 4800.....and have a rev cut off at 9500....
i was wondering which ecu is better...and if the p28 (if it is it) is better or worst...or can harm my motor...i used the p28....and only went to 8700...got too scared....hehe but the vtec pulled and screamed....and no check engine light..

 

don't forget about your secondary butterflies opening.......if i'm wrong i'll apologize now but from everything i've read, the chipped p28 won't control those. i'm not an ECU guru so it may be possible to re-chip them to control it, but i don't know personally. i would check to find out, unless you have a skunk2 intake manifold or some other intake manifold modified to fit your GSR head, in which case you won't have said butterflies.

 

ur right. is the engine "stock"? ( as in stock cams, stock manifold) if so, ur better off with the p72 ecu. the p28 is only good if combo'd with a single runner manifold, aftermarket cams and gears (valvetrain is the cams are too aggressive). otherwise, u'll lose some hp since the p28 will not open the secondaries.

 

what they said

if u dont plant on running some new camshafts and going for a single runner manifold, stay away from a chipped p28..your 2ndarys will be open all the time, resulting in some major trq loss, and on top of that your vtec will engage late, bad combo.

 

8700??? i hope that wasnt on a stock valvetrain. what mods do you have?

 

i have no idea wut u mean buy butterfiles.....and yes i am on stock motor....just intake,headers,exhuast....when my vtec pops at 4800, its sounds likegsr vtec, but when it hits from 6800 to 8500....it sounds like prelude vtec....if u guys understand wut i mean....it gets deeper....i dunt kno why, and is that bad?....should i seel this p28 and get my p72 back?

 

keep the p72 if u dont have a skunk 2 intake manifold..

 

Or just have a Single stage program tuned on the P72.

 

chip the p28

 

is this p28 going to harm my motor? cause im gonna go rev hard turbo.....when i go rev hard turbo, ill get a p72 back, but for now u think its safe to run the p28 NA...and pretty stock...

 

why do u want to do a p28? it's not going to help w those mods, u chip ECUs cuz u need to change the fuel curves and stuff when u have like head work and stuff. it's a waste of money/time to change ECUs otherwise esp if u know ur gonna keep the p72 for turbo. u dont wanna have a revlimiter at 9500 w stock valvetrain, u'll float a valve...

 

is it pointless to have a v-afc if you have a p28? which is better if so.

 

it's not pointless, but at this point u'll have better use of a vafc for ur car...even when u go turbo u'll still use it

 

damn, thanks for the help guys, but i already sold my p72, and i got the chipped p28....now i dunt kno wut to do, im not going turbo anytime soon tho.....wut u guys think i should do to my car now....to make it go quick....can i still advanced the timing...and just go up to 8500.....

 

should i keep the p28 or sell it and get the p72? can i stilll advance my timing on the p28 to make my car go a lil quicker? would it be safe?

 

ummn..i got a similar question too..ls/vtec in 97 hatch...98 block...95 gsr head...no mods but have skunk 2 harness for obd2 to obd1....have a p72 and a p28 that is getting chipped.....both are obd1 ecu's.would p72 work??i have asked a few ppl and they told me to go witht he chipped p28 because of some sensors or something liek that

 

OK. stick with he stock ECU!!!!! WHat i have heard from other is that they like to keep the stock ecu, and get a vtec controller, of a standalone computer. That way you can control your vtec cross over point, and with the standalone system, you can get rid of the fuel cutoff, and raise the rev limit. It just piggy backs into the ecu. Not that hard. Just like hondata. I think there are a bunch of these computers on ebay. take a look.