I got a 90 DOHC ZC(black top) in my 91 Si Hatch over a year ago, with new Distributor, timming best, peformance 4-2-1 header and short ram intake. The engine should be pushing 130 HP at the crank without mods. The engine really never pulled hard after 5500k. I said WTF?? My friends 89 CRX SI would keep up with me just fine. The compression ran 175 PSI in all the cylinders! Oh well.

Now I've built a B16a with High compression(11.5:1), 8.7 lb flywheel, 11000K RPM rated dual valve springs, Hondata Heat shield, OBD1 PR3 ECU(yes it does exist) 4-1 Header, same short ram intake, 92 XSi YS1 tranny(4.400 ratio, I even counted all the gear teeth to verify the tranny type) . THE SON OF A BITCH DOES NOT PULL STILL at HIGH RPM. It falls on it's face about 6000k RPM. It's only a tiny bit faster than my old DOHC ZC.

WHAT THE HELL IS GOING ON? I suspect my stock exhaust.

 

stock exhaust does not help is your a/f ratio tuned for 11k?

 

I haven't taken it past 7K. I'm still *trying* to break in the rings. It still has the stock ECU chip with rev limiter and the stock cam are prolly only good till 8500k. I intend to get Stage 2 cams with stock idle cams for good gas milage. The engine pulls real good until 6500k.

 

Wow, stock cam? You won't be making power at 11k rpm. I would get that thing tuned with such high compression.

Is your engine balanced to take that kind of abuse? Other then that, get that thing tuned on a dyno w/ a wideband O2 sensor.

Ciao.

Jon

 

yea man, a stock exhuast would definitely strip you of any topend power especially when you got a good pair of headers. at higher rpm, the headers would flow good, but the air has to force itself through the exhuast. you cant have a bunch of parts that increase the laminar flow of the air, and expect it to flow through a peashooter afterwards. change it to a 2 1/4 or 2 1/2 inch exhuast system, and you will see a different.

also, are you sure vtec is turning on?

 

yep, your stock drinking straw exhaust is the culprit to blame. upgrade to 2 1/4" and maybe replace your cat with a testpipe if you really want top end power.

 

First:, I'm not revving the engine to 11k. The valve train can handle it, but my current cams will never make that kind of power. I'm only revving it to 8K now. I'm dropped the compression to 11.3.

Second: My Vtec was not initially turning on 'cause I had the Vtec oil presure crossed with the Solenoid. Once I fixed it, I could head the solenoid kick in and I head a difference in intake noise. I know Vtec work. To my disbelief, the car actually slows down when the Vtec cams kick in. The idle cams pull harder!

I've been in other Hybrid-swap cars, and they pull much harder than mine, and they were completely stock. These cars had modified exhaust an a CAI.

I'm also getting a CAI to replace my crappy short ram.

I was thinking about doing a custom 2 1/4 exhaust with a High flow cat, 18' magnaflow resonator and maybe a type R muffler. I'm want it to be whisper quiet!

 

Was the motor an automatic before you dropped it in?

 

The motor I got was a complete package with manual tranny with ECU. it's out of a 92' Integra XSi.

Last night, I look at my stock Exhaust. There were too spots I notice where the piping was almost crushed flat, but it was like that from the factory! It looks like a lawn mower would have trouble breathing through that piping!

 

take off the whole exhaust system and run it open header and see if it makes a difference. It will for sure tell you if your exhaust/cat is the culprit. if thats the case then get a higher flowing exhaust and run a test pipe.

 

have u even got that thing tuned? maybe im retarded but nowhere did i see that u said u tuned it....expecting a high performance motor to work to its full potential without tuning is expecting a superstar football team with a shitty coach to win the superbowl...sorry for the crappy analogy but it makes sense if u think about it

 

I'm not expecting to it to perform wonders. I expect it to perform like other STOCK b16s and it does not even come close. I timmed it to the crank pully, it not running retarded, the cam timming it right. The only real performance difference right now is higher compression.

I stated that my old DOHC ZC never peformed like it should have. D16a were giving me a run for my money! I know how to swap engines. I think it's my "1 inch" exhaust system that's making it lack High RPM (6000 +) power. There are 2 spots where the piping is squished pretty flat.

 

yeah ur small exhaust definitely has something to do with it...but it is not ur problem...just get it tuned and u should be fine....u also said that u got 175 compression across the board in an 11.5 cr motor...either u performed the test with a closed throttle or something is seriously wrong with ur motor....i ran 210 psi on a stock block b16..

 

I'm running 240 PSI across. I my old ZC was running 175. I'm using new rings, so I'm hoping they'll break in and that 240 will go up. I had the head checked and the valves seal real well. I'm dropping the compression to 11.0 by changing the head gasket back to the stock 3 layer. I'll tune it once I buy an Exhaust temp and a wide band O2.

 

why r u droppin comp. back down to 11?
my advice stays the same...get it tuned...u will finally be happy...

 

I'm dropping because I was using 1 layer from my old head gasket. I was not sealing, thus air was being presurized into the water ways. I had the head resurfaced (-.005), and I've been trying to get ahold of a 2-layer mugen headgasket, but nobody has one in stock. I've gotta put the engine back together this weekend and drop it in. There is an import race here in Boise on Sept 2. I've got an OEM gaket coming in.

If you can convince me, I might remove the middle layer, I'll get 11.3:1.

 

what convincing do u need? u can still use the single layer if u want...just spray each side with sum copper spray and ur good to go...the copper spray helps to fill in any imperfections u may have

 

is copper spray avaliable at local auto stores? I had the head milled, so I'll be running even higher. I was afrade that when I get Stage 2 cams, they'll hit my pistons since I'm only using 1 layer head gasket and -.005 on the head.

 

yeah auto stores should have it...ive never used a single layer HG, so i dont know about that...but .005 is a very mild mill so u should have no problems with clearance..

 

Thanks for the info. I'm gonna clay is when I get the cams. I'll be running 11.6 with the head milled. I'm using C-Speedracing compression calculator to get these number.

I can't wait to get time to put a new exhaust in. I'm convinced the exhaust is what's causing me to loose alot at high rpm. My old stock DOHC ZC never really pulled past 5500K either. For now, I'm gonna chop out those flat spots and weld in new bent piping. I'll post pics when I get the chance.

 

I've ran 2 1/4 exhaust with a test pipe, 20" resonator, and Magnaflow universal oval muffler. It pulls much nicer at top end now! And the exhaust is real quiet! I got pipes and had them bend to match my old exhaust. I welded everything together.

The cost was: $40 for labor and piping, $75 mangaflow muffler, $20 for resonator. That about $140 with tax . awesome deal! I highly advise this setup for the budget conscious honda fan. I'll get a dyno up soon.