I hate to say it but for some reason my DOHC ZC is a slow piece of %^&!! I hope it didnt come to this name calling but i tried my best to make it fast... I got beat by a stock 91 crx si with a sohc ZC... and by plenty of other slow cars.... I know im not the best driver in the world, but i can beat more people with my stock crx si... well... here is my set up...
1989 crx dx, DOHC ZC, head is ported and polished, 5 angle valve job, new valve springs, new retainers, rebuilt bottom block (all new bearing/rings), balanced crank, ported out intake manifold, DC headers, intake, trust exhaust, adjustable fuel pressure regulator, 89 integra ecu, 91 si tranny, ACT 4 puck clutch, and a 60 shot nitrous set up (which i hardly ever used).... and my car is still slow.... the fastest time in the 1/4 mile was 16.1 all motor and 15.8 with NOS... and i know that some of you think that i cant drive, but other people have driven my car and they get slower times than me... Well i have had this set up for about a year now and i am getting tired of getting smoked by stock cars... my stock 89 crx si seems faster than my ZC... i feel that the ZC lacks torque, but i dont know what to do, i have no ecu codes, the cam timing seems to be correct, the compression on all pistons are around 200 psi, and i just dont know what to do... i would be happy to just hit low 15's...
well.. i am building an LSVTEC but i would like to get this ZC to run like its supposed to, i have seen people with stock ZC's hit low 15s at sacramento raceway..
If anyone in the bay area knows how to tune ZC HELP ME!!! ill pay for your time... any suggestions??? comments??
thanks


[Modified by crxtreme27, 12:57 PM 2/27/2003]

 

did you ever get it tuned...go to a dyno and see whats up...16.1 is pretty wack times i got that with a 91 crx si and a greddy exhaust...

 

i would have to agree that something is wrong here. What kind of tires do you have? many stock SIs can pull a 16.1 with good tires and driving...

 

your times sound horrible with all the work done already.something is not right.what ecu are you using?i assume your on an si tranny.dyno that puppy and find out whats up

 

Do you have 800 pounds of car stero in the trunk? I ran a 15.2@90mph all motor with no major mods.


[Modified by ZC_CRX, 5:58 PM 2/27/2003]

 

what tranny do you have??

i was running 16.5 with a hf tranny, with an intake and clutch

bought an si tranny, focuz header, no cat, and integra ecu and ran a 15.2

 

Isn't the SOHC ZC 130hp as well?

 

yea...the sohc vtec version

the sohc non vtec zc is more or less the same motor as the 88-91 si

 

haha.. well actually the time i ran a 16.1 i had to 12 inch speakers, when i took everything out, i ran slower.. haha.... as for the tires, i have ran with 17" racing rims, and with the stock 14" rims... i guess im gonna have to go dyno that thing and try to figure something out... do you guys think it might have to do something with the wiring?? however, i am not getting any codes...
thanks

 

17 inch racing rims? um try something more along the lines of a 14 or 15 inch
also what was your 60ft time?


[Modified by civbeater90, 1:53 AM 2/28/2003]

 

sohc zc non vtec is 119 hp 100 ft/trq. I mostly noticed it maintaining 100+ mph speeds, and since it was a little less used it is a little stronger also. I've got a wagovan i run something along the lines of low 16s, motor's stock and its around 2700 w/ driver.

 

just because you have done so much doesn't mean you have gain a lot. Tuning that motor will be the first thing in mind. if you can get to a dyno and find out.

just to let you know if you took the motor to someone(place) to do the job of porting/polish and everything else, it doesn't give you a guarantee that it was actually done.

Believe i know a mechanic who would literaly steal the parts from customers and tell them he had installed them... who knows!!!


[Modified by joey1320, 2:21 AM 2/28/2003]

 

you dont need a dyno to tune your car.....go to a local garage that can run a scope on your car it will tell you exactly what your car is doing from a/f to to spark line/firing line, your sensors...anything man...and it will cost like 50 to 60 bucks takes about 20 min. and they can give you a printout if you ask for it...

what is your fuel pressure set at? and have you did really any thing on your car like a vacuum test? manifold vacuum will tell you just about anything in a car....but that will show up on the scope as well...

just get it tested and go from there instead of going to the track and running slower and slower times.

 

Think about it you guys, he's rebuilt the motor, everything checks out, he should be putting out 140HP to the flywheel at least...

I think the exhaust is the problem. Specifically, the catalytic converter . This is just a guess - an experienced guess.

My setup was running very strong when I first installed my PG7 ECU (vs. PM6), but now it feels VERY sluggish... A few days ago I took a peek inside my catalytic converter (due to some strange noises coming from it) and all I could see was black carbon buildup!!! This makes perfect sense, because recently I've noticed my exhaust being MUUUUCCCHHH quieter compared to how loud it used to be. Like yours, my compression is very strong, everything is in great shape. But a clogged cat can be a MAJOR restriction in the exhaust system, seriously hurting perfomance.

I have since installed a V-AFC, and my B&M Adjustable FPR should be coming very shortly. With these mods I have been (even more so with the FPR) able to lean out the fuel mixture quite a bit. So with my NEW catalytic converter that I just recieved, I won't have to worry about clogging it because of my latest mods.

Along with checking out the cat, it might be worth it to replace the O2 sensor, and get a A/F guage... Chances are, you have been running rich for quite some time.

Just something to consider.

[Modified by MrTodd, 9:55 PM 2/27/2003]


[Modified by MrTodd, 9:57 PM 2/27/2003]

 

im just curious as to what your 60ft times were?

 

Kinda stupid question but are you shifting at the right RPM? Also might try taking off the 17s...other then that i have no clue wtf is wrong... unless somehow you are a really horrible driver but i dont think thats the case.

 

Okay just my 2cents, but heres somthing to think about.

Your port and polish job: who did it and how? Did they know what they were doing with a 1.6l motor? Ive heard stories from friends of port and polish jobs gone wrong by people who didnt know what they were doing. You can really mess up the flow of a motor by doing it wrong. Too much flow not enough back pressure and youll acually lose HP.

Then of course tuning. With all that gear, you need to tune the car a bit. Let us know what happens.

 

I think i might just take it to the shop like Kasper 1 said and get a scope.... as for my fuel pressure, well i have tried from being 30 psi to about 42 psi and the times just stay at about the same.....

MrTodd - I think I do have to change my catalytic convter, i have not changed it in years, that is my next mod in my list, now should i get a high flow cat, straight pipe, or the stock??? and as a matter of fact i was running rich for quite some time because my sparkplugs have been black even if i lower the fuel pressure.....

civbeater90 - my 60 ft times are not great because lately i get a lot of spin on my 14" rims, but they range from 2.3-2.5.... i always launch at about 2-3K rpm

ThE bEe GuY- Shifting, at first i was shifting at about 7000 rpm, then i tried at 6800 and 6600 but they all give me about same results, well the 6800 seems to give me the better ones tho....

ZCcivic91 - for the past couple of months i have been thinking of buying a stock head and changing it over because that is about the last thing that could be wrong.. the shop that did it for me has been around for a long time but they do mostly work on american cars... and i do know that they did all the things i asked them to do, but i am not sure if they did it right..... is there a way i can check this?? or should i just get a stock head and swap it over???

Thanks guys for all your help!!!