I have a B20B w/P8R intake exhaust, I am using my stock 93 5spd B18A ECU. Will the ECU be able to compensate for the added displacement (.14L) and larger (33mm vs 31mm) valves? I was thinking it should, based off of the ability of the O2 sensor to read that the mixture is more lean than it was before. SO my question is are there maps in the ECU tables that can compensate for small changes of that scale? Would they be consistent thru out the RPM range? Thanks.
Need Knowledge please.
no your fine just use the block and head.
and rip everything off you old eng.
did that 3 weeks ago, motor runs fine. I am just wondering if it is running lean due to larger displacement larger valves etc… Know what I mean?
I thout the same thing but I have been told a few times that the
computer/electrical. dont efect the mechanical.
I guess to break down the question to simple form. Will the A/F be lean because of the larger displacement and larger breathability of the valves? IE. Does the ECU have maps to compensate?
Yes it is probably running lean and definitely not to its full potential. It would be the same as sleeving a B18, boring it to 2.0L (much larger than a standard rebuild), installing different pistons, installing vtec sized valves (P8R), installing a high flow intake and exhaust, and then not tuning it. I actually had to have my ECU chipped and my car dyno tuned just to get it to run right with my B20Z in my 92. Mine was definitely running lean, and although I believe the ECU was compensating to a certain extent, it is not designed to constantly compensate for such a major change.
By the way, here are my results after tuning, and yes I could tell a major improvement after tuning (engine runs way smoother and has a lot more power):
http://www.g2ic.com/forums/showthread.php?t=151829
hey i have a question how do u tell if your car has a p72 ecu with hondata s100 . .is there a physical way to check?? cause im purchasing a teg soon and wanted to know:cool:
Thank you Phatty, finally an answer to my question. Ay idea what you were running before your tune whp wise? How far out of stoich were you? Sorry fierro I find your question completely irrelevent to my question so I will not even bother to entertain it. You could always post your own question.
sorry dude:auto: i got lazy
No problems.
I don’t know exactly how far out it was or what it was before, as he didn’t want to rev it high and tear something up with it being out of tune. He basically did it where he would start with only reving it to 2k, look at the results and tune, and then rev to 2.5k, etc. I don’t remember exactly where he started or the intervals that he used, but he wasn’t reving it very high until the low end was all tuned. My idle was so bad that I had to have the ecu chipped with about 5% more fuel just to get it to idle right so that I could set the timing and be able to drive it to the shop for tuning, and I was told to “drive it like a grandma” on my way over there. Considering this corrected my idle problems and made it run well enough to drive, I would assume that this was close to the amount off it was from what it should be, however, running on the richened b18 fuel map was still not all that great. By the time he was done adjusting it a little leaner and a little richer at various points all the way up the rpm range, I now have a completely different fuel curve. Basically I don’t have a baseline other than I know that my engine is rated at 146hp/133tq at the flywheel in a crv, and some other dyno sheets on the internet where I have seen it only make about 138whp (if I remember correctly) on a stock ecu with i/h/e and a test pipe in place of the cat (I was making 146whp/137tq with i/h/e and a stock cat). A stock tach is generally about 500rpms off by the time you get to the top, and my redline is 6800 on my current setup, so my tach reads over 7k when I redline it and is smooth all the way. My driving style recently has been an average speed of around 80-100mph on the highway and intentionally flooring it as often as possible and generally running it hard in order to clean out the cat and injectors really good (injector cleaner was also used in this tank of gas) due to it having been sitting for several months before the swap was completed. Well, that is my excuse, but really it is just so fun to drive and doing this mine got 32mpg when I filled it up this last time.
Oh, and if you haven’t seen this already, here is a little more info on your engine (considering the numbers Honda was quoting on your engine, I would expect very similar results to mine after tuning):
http://www.tuneruniversity.com/forums/showthread.php?t=1900
Anything else you wanted to know about the B20? Due to the general lack of info and misinformation about the engine, swap, and tuning, I am willing to help anyone as much as possible.
Mods please archivethis since everyone doing this swap needs to read it. Chipping my ecu and tuning was my last resort after my car wouldn’t run right no matter what I tried, when it should have been in the plans from the beginning with this swap.
Thanks again Phatty, a couple more Qs. From your personal experiance would you judge the cams to be the same as a OBD1 teg cams? Do you know if B20B P8Rs really have a 9.2 CR? I already have it in my 93 RS, so no need for help with the swap. Also what ancillaries do you still have in the car like P.S., A.C. etc…?
I would say that the b18a, b18b, and the b20b cams are all the same from what I have seen and read. I have the B20Z and according to what was posted in that link in my previous post, they have a slightly higher lift on the intake cam, and I would say that my cams are definitely not any worse than the previous b18a (I’ll take their word for it). If you want to upgrade your cams, basically there is not really a stock upgrade unless you feel that the B20Z cams are worth upgrading to for that tiny bit of extra lift on the intake cam. I haven’t done any research on aftermarket ones yet.
Yeah the B20B with the P8R head has the 9.2:1 compression - I have seen this from many sources.
I removed my power steering and put in a 88-91 Civic manual rack during my engine swap (wish I had the quick-steer kit in it). I will be running A/C when I get it fixed, but the belt is currently not on it since the A/C is not working. So basically, right now I am running nothing off of the crank pully other than the alternator.