In the interests of pumping up the tech here, this gets a new thread.

I just bought a 94-95 OBDI GS-R ECU tuned for the H22a (mugen spec apparently), with a 9500 rpm redline

Question #1: Should I believe it was tuned for the H22a? I say yes. Why? He was running this ECU in a turbo integra (bought it like it is now)...so I ask him if he was running rich, and he said at first he was fouling up his plugs and black carbon ish was blowing out the exhaust pipe...why would a tuned GSR ECU run so rich? Because the fuel maps are for a 2.2l H22a and not a 1.8l B18c1! Agree?

Anyways let's cover what I need to make this work. The first step is valve springs an retainers for sure (redline is so high)! Comment on this setup, assume I have all bolt-ons and a V-AFC but stock cams and pistons.

Basically, I just want to ensure I don't float my valves until I bump the compression and get better cams. BUT I probably won't have much more power above 7500 for the time being?

Pistons (Type-S, depends on $$$), agressive cams and all the other internal polishing blah blah.

How does this sound? Should be doing anything in a different order? Thanks

 

I wouldn't go above 9k rpms with the lude motor. Even with seriously agressive cams, you won't make power above that anyway. Besides, the other internals of the head aren't designed to take that kind of abuse.

Oh, and keep one thing in mind, the GSR injectors are smaller, so it will be running more fuel to compensate. Don't judge how rich his car was running to mean that it was designed for a Prelude. Who did the reprogramming and did he get any documentation for it?

 

No documentation unfortunately, but I got it for the same price as a stock p72 so I said what the hey, take a chance. Basically it's got some writing on the side "Teste H22 Smooth" in like nail polish, and on the inside on the chip is a sticker with a hand written "mugen spec", like they were swapping chips and tuning. It's exactly as they bought it. I'm suspicious but interested. Either way it is programmed if it will go that high for the redline.

Aren't injectors irrelevant because the seller had this GS-R ECU on a GS-R? it would be the same injectors, so running rich leads me to believe something is funky with the programming. I will test it on a GS-R first before it goes on the prelude.

Is there a way to just get a readout of the ECU settings, then I could compare...



[Modified by satan_srv, 2:03 AM 6/21/2002]

 

well. . . this may be irrelevant becuase your ecu isnt a true p72 anyway, but just for giggles. . . .
9000 is ridiculous, even with valves and retainers. until you have the cams and pistons to get the power up there, why be there at all?
as you can see, the power in an h22 starts dropping before 7000 rpms.


also, for people that want to use a gsr ecu, it works, but it's a lean little bugger.




[Modified by sloaccord, 8:38 AM 6/21/2002]

 

Yup! I only bought it under the impression it was tuned to H22A Mugen fuel specs, if not I'll propbably sell it, unless I can tune the A/F just right. But thanks for confriming the power just wouldn't be there over 7000. Actually it's worse on a 4th gen then 5th. So I might as well wait and do the ECU valves springs, retainers, cams, and pistions, rings at the same time?

My only thought is that if I had the stuff why not put it in if the fuel maps are better and give better performance over the P13 from 0-7400? I could just not take it over 7,400 cause I would know that would be a waste. Later on I could always get the redline lowered...

 

Just get an MSD ignition. MSD 6AL and use the rev limiter chips that come with it.

 

Ahh good idea, thanks Todd. Why does the MSD come with rev limiter chips anyway? You can also rais the rev limiter with them?

I will not be putting this on until my dyno time next month. I plan to do a back-to-back run against my p13 ecu. I will defintely post the results so we can see whether this H22A spec or not. We will have a Wide Band 02 as well so we can see if I am running lean. If everything seems good we'll tune the V-AFC and we're good to go.

Let's talk about injectors. I was reading an old topic about B18C1 injectors vs. H22A injectors. It's an OBDII 96 (doing the swap with the 94 OBDI). So these cars have the same injectors or different? How will this impact performance?

 

same style injectors I believe, but someone will have to back me up on this cause I'm not 100% sure. You have OBDII, but you have the H22A1 block. I think they stuck with the 310's until 97 when they went to 270, or was it 290? No, 270... that's is. Damnit, too early.

The only thing to be concerned about is peak and hold vs saturated... and honestly, someone else on here with a little more personal experience should probably answer this, cause I'm just gonna **** things up. lol

Hrm, another option is calling RC Engineering try asking. They might know. *shrug*

I DO know that the GSR injector is smaller than the lude injector.

 

I think you're right, OBDII and the old injectors. So Todd are you the only guy who answers questions around here?

Okay, now say I wanted to raise compression now. Would JDM H22a Pistons/Rods be a cheap but smart choice? They are 11:1? Then if I want to raise it more I can mill the head later? Would I also need the JDM Valvetrain? Or can I run the USDM valvetrain and just upgrade the springs/retainers?

 

the regular JDM pistons are 10.6:1 I believe. The Type S is 11:1. If you ran Type S pistons and had the head milled slightly then you should be end CR of 11.2-11.3:1. That's enough for about a 10-15 hp increase. TRUE hp. Not this "my header gave me 24 hp" but the dyno will only show a peak of 4.

My only concern is the redline. With a still stock rotating assembley on the bottom, even with Type S, you aren't going to be able to rev high. I would do the springs and retainers when you have the head off, whether you're going to rev high or not... miss a shift and you might be glad you had them there.

Perfect world, you'd sleeve it and run forged pistons with some nice rods. But, sleeving is a bitch, you have to pull the block, then have the sleeves punched out and the others installed.

IF you are't going race it hard, and often, just a good, quick street car that owns a few people here and there, then Type S pistons, a nice set of cams (not too crazy, or you will lose power) a valve train upgrade (JG, Crower, WebCam, Ferrea etc) and you should be happy.

 

Thanks dude, you know what I want...good quick street car.

However I think JDM H22a pistons/rods with a milled head would get me to 11.0:1 then? That's not bad at all...for the price. Type-S pistons run $650 or so I can get this stuff for waaay less. However these are not oversized, will I run into any problems? I have 90,000 miles...

What rotating assembly upgrades are available and at what price? Thanks again

 

if you're oging to start spending that kind of cash, then you might want to contact a few engine builders.

http://www.JGenginedynamics.com... they did mine. good luck if you go with them. lol, Nancy that answers the phone is the spawn of satan, but rumor is that she and Javier are together. I don't know that for a fact though. Anyway, if you can ever get someone other than her on the phone, (Joel is good) you might try talking to them.

also, KG motors, R&D... tons of them out there. Kaufman motorsports did a good job on warren's lude. portflow can help you with head stuff... laurie @ http://www.webcaminc.net might be able to point you in the direction of a few decent shops in your area if you wanna go talk to someone.

 

I am 90% sure that the 1996 H22a, despite it being obd2 compliant, still uses the peak and hold injectors. The P72 has saturated injector drivers. The P72 reprogrammed with H22a specs is a good choice for 97+ H22a motors because the 97+ have saturated injectors. It all depends on what injectors you have on your 96...

Also, Mugen never made a program for the H22A. The program on the ECU is likely the B18C Mugen program - which runs extremely rich and in open loop mode all the time. The 9500rpm redline is a dead givaway that this is not an H22A program. The laws of physics limit the rev pontential of even a fully balanced and built H22a to about 8500rpm.

Also, the "mugen" program on the P72 likely will have no control over the secondary intake manifold butterflies. So they will be stuck open all the time - which will really suck for low end on an H22a.

Andrew

 

yeah, what he said.

and that answers that

that's not a bad thing.

unless it was a custom program styled after a mugen one. Improbable, but possible,

it's more like 8800-8900.. but close enough.

that's why you just remove them and get better flow for top end. That's where we race isn't it? lol

all in all, you're very right.

 

Hmm what a pain...why would they disable control of the secondary IAB? Do they hinder top end performance? The regular P72 controls this...oh well. So if I like the performance (I will have to raise the VTEC crossover for sure) I can limit the redline down to 8500-8900 with the proper internals..so what rotating assembly can I upgrade to?


[Modified by satan_srv, 11:41 AM 6/21/2002]

 

ANother thing to add is that the GSR ECU stock on an H22A has a more even diminishing curve from peak hp.


Depending on how many RPMs you drop when you shift...it may be just as beneficial to ride all the way to 7500 to stay in gear longer... because the drop in power is not as sharp? And with the hopefully *tuned* fuel maps it should be even better...so even with a stock GSR there is more power later in the powerband and it does not drop as quickly.

 

yes! the main reason i hold gears till about 7900 rpms is to battle the rpm loss when i shift. . . .
also, it just so happens i have some JDM 10.6 to 1 pistons sittting next to me right now. they're in great shape- just out of a motor- you want em?

 

I'm scoping some right now. How many kms and how much?

My only concern is about releeving or honing? Can I get away with sticking stock pistons back in? I was under the impression if you change the pistons you will either have to get over bored pistons or get the cylinders resleeved, which is $$$

 

You can use the stock pistons and just get new rings and you should be fine. I have a set of JDM H22A pistons that I replaced with typeS pistons, and they only have 28000 miles on them. They have been cleaned and I still have the wrist pins with them. I'll let them go pretty cheap becuase they aren't doing anything for me. IM me or post up and give me a price and they are yours pretty much.

 

the p13 pistons are in great shape; they have about 40k miles on them, and they still have the rods attached.

 

would someone like to explain to me why an h22a can't rev to oh say 10k? considering i've had them to 9k with stock internals.. and mine should be making power till 10k with the cams, valvesprings, and valves i'm using... whats stopping its rev?

 

The problem that the H22A has with RPMs is the long stroke of the motor. With its 87mm bore, 90.7mm stroke, and 1.577 rod ratio, it is essentially a stroker motor from the factory. It is way undersquare. Undersquare is good for developing torque low in the rpm range. Undersquare is bad for high RPMs because of two main problems. The first problem is that the short rods the long stroke requires generates extreme forces on the sidewall of the cylinder. This side loading creates abnormal ring, piston, and/or cylinder wall wear as well as stressing the rods at angles that they were not designed to be stressed at. The second problem this setup will have with RPMs is piston speeds. The acceleration and deceleration of the piston between TDC and BDC is a direct result of the stroke. The longer the stroke, the faster the piston must decelerate to a stop at the bottom of it's stroke and the faster it must accelerate again from that stop upwards again. This rapid acceleration and deceleration causes the rod ends to "egg" at high RPM.

And there are other issues to think about too other than just the forces within the cylinders... For exaple how is your oil pump going to handle 9000 rpm? Will it be able to supply enough oil? What about the water pump? What if it just cavitates at high RPM? (a likely scenario...) Then you'll be overheating and warping heads.

The design of some motors permit them to run to 9000+ rpm semi-reliably. The H22A is not one of those motors. I don't care what kind of rods you have in there, because it's not going to last too long at 9000+ rpm no matter what you do. You cannot fight the laws of physics...

Andrew


[Modified by aklucsarits, 3:24 AM 6/22/2002]

 

Once I get the ECU I'm going to get a dude to analyze it and tell me what it's specs are. In a month when I dyno tune with the P13 I will plug this P72 in for a run (to stock redline of course!) to see what it can do. I will post up the results, hopefullt they're good.

 

Can you explain to me why you think it is so important to rev to SAY 10K? You must have no bottom end on your car......

Sorry it must be me but, I would rather have alittle low-end with my high-end...

Look at me Im revin at 10 grand............wooooooooppppppppeeeeeeeeeiiiiiii ii
But I have 158 TQ at 8 grand..................

 

wasn't planning on revving till 10k, crower says the valvetrain and cams i have will make power till 10k.. so i was under the assumption it could go that high.. and its crower rods, je 9.0:1 forged pistons, and eagle sleeves in the bottom end