98 Type R with P28
03-23-2003, 12:00 AM
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Actually the P72 is a better ECU to use, it actually has a knock sensor input, which is a pretty nice thing to keep. Either way, with a P28 or a P72, you're gonna be changing the chip in it, you might as well at least use an ECU that is a little more current, and was at least originally made to run in a DOHC Vtec car, rather than anthing else. Either way, realistically, it's what ever you can get cheaper or faster. Otherwise don't worry. They both take an aftermarket OBD1 chip...
Oh yeah, dont use the Mugen program, especially as it's probably not the real mugen pogram, unless you're spending a grand from King Motorsports. See if you can get a Skunk2 knock off program, you'll be better off.
See www.Locashracing.com
Later,
Aj
Oh yeah, dont use the Mugen program, especially as it's probably not the real mugen pogram, unless you're spending a grand from King Motorsports. See if you can get a Skunk2 knock off program, you'll be better off.
See www.Locashracing.com
Later,
Aj
03-24-2003, 07:49 AM
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Will it make extra horsepower by just convert the car from OBD2 to OBD1? My car has DC 421 header, Apexi Dunk catback, AEM CAI. Do you think the power will just be the same as now ... or will increase?
Why people go OBD1 instead of 2 ?
Should I unplug any sensor ...like one of the O2 sensor at Cat-converter ,... or anymore ... ? When I convert OBD2 to OBD1? Or the ecu just automatically ignore those sensor?
Thanks~
Why people go OBD1 instead of 2 ?
Should I unplug any sensor ...like one of the O2 sensor at Cat-converter ,... or anymore ... ? When I convert OBD2 to OBD1? Or the ecu just automatically ignore those sensor?
Thanks~
03-24-2003, 09:25 AM
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I dont know about N/A cars but OBD1 has a less agressive program for boost then the OBD2. Jotech has proven 20whp gains off just a OBD1 ECU in a Turbo TypeR. I have the OBD1 in my car (got it just preping the car for the Turbo) and it by its self didn't feel stronger at all. Matter fact with the TypeR ECU I use to rev to 8777rpm(via VAFC) vs the GSR OBD1 which has never let me touch anything over 8222 rpms. Its been like learning how to drive the car all over again. I hit that dam rev limiter aaaaaaallot since I put the ECU in but I've gotten better....I guess a shift light would come in handy....
03-24-2003, 11:06 AM
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Originally Posted by Erik B
I dont know about N/A cars but OBD1 has a less agressive program for boost then the OBD2. Jotech has proven 20whp gains off just a OBD1 ECU in a Turbo TypeR. I have the OBD1 in my car (got it just preping the car for the Turbo) and it by its self didn't feel stronger at all. Matter fact with the TypeR ECU I use to rev to 8777rpm(via VAFC) vs the GSR OBD1 which has never let me touch anything over 8222 rpms. Its been like learning how to drive the car all over again. I hit that dam rev limiter aaaaaaallot since I put the ECU in but I've gotten better....I guess a shift light would come in handy....
First off, OBD1 is not a program, it's a generation of ECU, in fact the most common OBD1 ECU is not at a P72(GSR) ecu either, it's a P28, which was like a single over head cam civic from back in the day. An ECU is only that of which it is programmed. For example, if you have a P28 or P72, the ECU could have a Skunk2 program, a Mugen program, or a custom boost program, all dependent on what you put in it, almost no one uses the ECU with its stock program, as for the most part, it wouldn't run right, expecially in the case of an ITR using a P72, where the P72 was meant for a motor with a dual stage runner manifold. For cars with boost, there is no such thing as a less aggresive profile in an ECU, and actually if anything, there is more fuel. On a side note, you can also reprogram an ODB2 ecu to spec, it'll just cost you an arm and a leg as well as a nice long delay.
If you have an old P72 (GSR) ecu, and it has a 8200rpm rev limit, then you have some serious issues, and may actually be running the stock program, which isn't wise, as it has pretty much no resemblance to what your car comes with. The only purpose of running an OBD1 ECU is tunability, it allows you to change the chip to something that is more fitting of your setup rather than the stock ECU, it also allows you to only run 1 o2 sensor and no cat if you so choose. Your stock ECU will be best for a virtually stock car, until you get into internals, becuase for the most part, it compensates for little changes such as intake, exhaust, headers, and so on.
So, your comment about it not feeling stronger, is more than likely, becuase it's not, or not substancialy, often times people think that just switching to OBD1 itself will give you horse power, when it fact, it's not the case. Frequently the only thing it does is allow for higher rpm and less restriction with respect to sensors and changes, this is why it is so much easier to tune an OBD1 car, especially with boost as a factor.
Later,
Aj
03-24-2003, 12:30 PM
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Thanks Aj 
I just won a pair of Intake and Exhaust Cam shaft from Skunk2 Stage 3. And will put them in once I found a set on adj Cam gears. My buddy has his 98 GS-R ... (Not Type R
) with Almost the same thing like I had. But he got the CTR cam Shafts + Testpipe + 3 custom Pulleys. His dyno test is 163.7 hp with OBD2 ...after his switched to OBD1 (stock 95 P72), he got 174.5hp.
That's why I plan to do the conversion! You think is OK if I install a P28 ecu in my ITR with all the set-up I told you?
What will be your suggestion? And what do you think about my friend's GS-R? He told me the best GS-R is "1995". You think so?
I just won a pair of Intake and Exhaust Cam shaft from Skunk2 Stage 3. And will put them in once I found a set on adj Cam gears. My buddy has his 98 GS-R ... (Not Type R
) with Almost the same thing like I had. But he got the CTR cam Shafts + Testpipe + 3 custom Pulleys. His dyno test is 163.7 hp with OBD2 ...after his switched to OBD1 (stock 95 P72), he got 174.5hp.That's why I plan to do the conversion! You think is OK if I install a P28 ecu in my ITR with all the set-up I told you?
What will be your suggestion? And what do you think about my friend's GS-R? He told me the best GS-R is "1995". You think so?
03-24-2003, 01:13 PM
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Well, starting, with the cams you "won", which by the way, where did you win them???? Any way, you will need the skunk2 valve springs, retainers, and more than like in addition to cam gears, may also need some injectors. Those cams are very radical, and to work sufficiently wil require substacially higher compression then stock. I'd say something closer to 12:1. They will also require a nice header, test pipe or high flow cat, and free flowing exhaust to breath properly.
As far as switching to OBD1, if he had a 98 GSR, likely to not, he switched to OBD1 and gained 11whp becuase he had the ECU chipped, though he may say it's stock, or even think it, chances are if he got it off line, it was chipped, unless of course he is running a vafc or something like that, and thats where he got the additional hp, is from tunning. Running the the 00-01' ITR cams, or CTR, both the same, requires a little more timing, a little more fuel, and unless he chipped it, the older GSR and the newer all had very similar ECU program wether OBD1 or 2, and not likely to make up an 11whp difference.
Any way, if you want to put a P28 ECU in your car, keep in mind that you need an obd2 -> obd1 jumper harness/conversion, in addition to having it chipped, as it won't work stock. If you decide to do a P72 or P06 or something along those lines you will also need it chipped as it was not meant to run correctly in your car and will have all the wrong fuel and Vtec maps. Also, most places that chip ECUs will allow you to set a custom rev limiter as well as a custom Vtec engaugement point. In the case of rev limiter, I would put in no higher than 9600 for a daily driven car, and as for Vtec, in order not to have a huge dip into vtec, you may want to move it up to about 6300 or so, maybe even a little higher. Realistically, I would invest in a Hondata or something like that as per your budget will allow it, as those cams are a little out of the ordinary, you'll have some issues getting them to run well on a standardized ECU rom program such as the Mugen chip for example.
As far as your friends GSR, I wouldn't waste the money on CTR cams again, I tried them out prior to finding out they were the same as my 01' ITR cams, soon after dynoing the exact same numbers, give or take a couple tenths due to the valve adjustment, I was kinda teed off, but I guess, live and learn. Any way, the 95 was not the best year, in fact from 94-96 they were identical, in 97 they switched it up a little as far as computer goes, but other wise nothing, then in 98 they changed the front and rear facia. Other than that, until 00' everything stayed the same from top to bottom, then until they discontinued it on 01' it was exactly the same. On the whole, 94-97 they made very few changes if any, and then 98-01' they also didn't change a lot. I was more body styling than anything. Any way, good luck with your car, and seriously consider selling those cams for some less aggresive ones, that will require less modification to what sounds like an almost stock R. I'd look into some skunk2 stage 1 or something like that, that wont require a huge investment or a lot of peripheral parts.
Later,
Aj
As far as switching to OBD1, if he had a 98 GSR, likely to not, he switched to OBD1 and gained 11whp becuase he had the ECU chipped, though he may say it's stock, or even think it, chances are if he got it off line, it was chipped, unless of course he is running a vafc or something like that, and thats where he got the additional hp, is from tunning. Running the the 00-01' ITR cams, or CTR, both the same, requires a little more timing, a little more fuel, and unless he chipped it, the older GSR and the newer all had very similar ECU program wether OBD1 or 2, and not likely to make up an 11whp difference.
Any way, if you want to put a P28 ECU in your car, keep in mind that you need an obd2 -> obd1 jumper harness/conversion, in addition to having it chipped, as it won't work stock. If you decide to do a P72 or P06 or something along those lines you will also need it chipped as it was not meant to run correctly in your car and will have all the wrong fuel and Vtec maps. Also, most places that chip ECUs will allow you to set a custom rev limiter as well as a custom Vtec engaugement point. In the case of rev limiter, I would put in no higher than 9600 for a daily driven car, and as for Vtec, in order not to have a huge dip into vtec, you may want to move it up to about 6300 or so, maybe even a little higher. Realistically, I would invest in a Hondata or something like that as per your budget will allow it, as those cams are a little out of the ordinary, you'll have some issues getting them to run well on a standardized ECU rom program such as the Mugen chip for example.
As far as your friends GSR, I wouldn't waste the money on CTR cams again, I tried them out prior to finding out they were the same as my 01' ITR cams, soon after dynoing the exact same numbers, give or take a couple tenths due to the valve adjustment, I was kinda teed off, but I guess, live and learn. Any way, the 95 was not the best year, in fact from 94-96 they were identical, in 97 they switched it up a little as far as computer goes, but other wise nothing, then in 98 they changed the front and rear facia. Other than that, until 00' everything stayed the same from top to bottom, then until they discontinued it on 01' it was exactly the same. On the whole, 94-97 they made very few changes if any, and then 98-01' they also didn't change a lot. I was more body styling than anything. Any way, good luck with your car, and seriously consider selling those cams for some less aggresive ones, that will require less modification to what sounds like an almost stock R. I'd look into some skunk2 stage 1 or something like that, that wont require a huge investment or a lot of peripheral parts.
Later,
Aj
03-24-2003, 04:33 PM
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[/quote]If you have an old P72 (GSR) ecu, and it has a 8200rpm rev limit, then you have some serious issues, and may actually be running the stock program, which isn't wise, as it has pretty much no resemblance to what your car comes with.
Later,
Aj[/quote]
I said its not stronger because I know that changing just the ECU doesn't do shit. What's a stock GSR's rev limiter kick in at? I have a bone stock ECU and it doesn't go over 8200rpms. Also I was told by Tony at Jotech it has less agressive fuel curves......is that worng too?
Later,
Aj[/quote]
I said its not stronger because I know that changing just the ECU doesn't do shit. What's a stock GSR's rev limiter kick in at? I have a bone stock ECU and it doesn't go over 8200rpms. Also I was told by Tony at Jotech it has less agressive fuel curves......is that worng too?