Zex 105300 in rebuilt y8 still giving problems..

[sir_lagalot]

i posted a topic about this before.. i bought a zex 105300 stage-two cam w/ springs and installed them on this rebuilt y8 head i bought off ebay.

upon installation, there was an increase of 12-14 whp but the car was incredibly sluggish upto 3200 rpm. I could floor it in second and it'd be like turbo lag..the needle rises REALLLY slowly upto 3200 while i hear this 'sewing machine' like sound from the engine, and then at 3200 rpm theres a kick and it goes smooth from there on. its impossible to drive in the city as it misses and jerks in low rpms. upto 3200 i think a go-cart could give me competition.

First time i installed the cam in the head we found it to be making the most power with the cam advanced 4 degrees at which point it made 127 whp.

as per a members advice here i had them recheck the cam and crank marks and the cam was a tooth retired which they fixed. Now everythings aligned perfectly at tdc, and i had them dyno tune it again with the dizzy in the middle.
Results...

1st Dyno run with cam advanced 4 degrees: 124 whp.
2nd Dyno run with cam advanced 2.5 degrees: 130 whp.
3rd Dyno run with cam at 0 Degrees: 119 whp.

They moved it back to 2.5 degrees advanced and it made 129 so they left it there.

before it was making a little less than this at 4" advanced, now its making more at 2.5" degrees advanced since they aligned the cam properly with the crank at TDC.. trouble is, stuttering is still there.. cars still incredibly sluggish upto 3200 rpm.

sorry for the long post... does anybody here have a clue as to whats the problem now? i advanced the dizzy at home, and it made things a whole lot better, it was smooth upto 3200 rpm but even then i can feel this kick at 3200..

[sir_lagalot]

guys at the workshop are blaming it on the cam, saying i wouldnt be facing these problems had i gone with a skunk-2. the fact that things are at least 70% better with the dizzy advanced a bit makes me doubt its a faulty cam.

my setup at the moment.
rebuilt d16y8 head off ebay, with zex 105300 cam + springs. SRP 10.5 comp pistons. i/h/e. msd ignition. plugs + wires. LSD.

www.cardomain.com/ride/2094186

[cory jordan]

have you spec'd this cam vs a lesser zex cam?. maybe you got the wrong one sent to you. or something along thoes lines. get the cam card and match it up closely with another 'stage 2' cam and put it in. and see.. shouldnt the zex cam have a number on it that corresponds to its grind?. just some ideas.

[s_18]

I thought the 105300 was more like a stage 3 cam... If so you need tuning to get it right, or atleast that's what I imagine.

[sir_lagalot]

its a stage-2. required no head modication, only spring upgrade. duration and lift is nowhere near a stage-3.

cant seem to figure out whats causing the missing . i have to keep tampering with the dizzy on and off for city driving or dragging.

[cory jordan]

hmmm . if you say its a stg 2. and you know it is. i dont know really whats up. thats weird. not a nice gain imho. wait. what was the stock numbers?

[sir_lagalot]

before the head/cam dyno'd in at 115 whp. after 130. to tell you the truth i wasnt expecting anything above 10.. its a stage-2 cam..people were telling me to expect a gain of around 10-12 max.

i'm gonna try advancing the dizzy all the way with 91 octane and see if that gets rid of the lag totally as per siregcivics advice.

[mugenej8power]

only thing i can think of is to tune it.

[dragman99]

before the head/cam dyno'd in at 115 whp. after 130. to tell you the truth i wasnt expecting anything above 10.. its a stage-2 cam..people were telling me to expect a gain of around 10-12 max.

i'm gonna try advancing the dizzy all the way with 91 octane and see if that gets rid of the lag totally as per siregcivics advice.


i guess it's possible it's getting waaaay too much fuel before 3200rpms. when you say it's missing, do you mean like, it's skipping?

[gloryhog]

i guess it's possible it's getting waaaay too much fuel before 3200rpms. when you say it's missing, do you mean like, it's skipping?

I would garranty you that it is running poorly due to the tune...Way to rich at idle through 5k...

did you use any kind of Engine mgmt. ? or did you just drop the cam in and play w/ the timing ?

[Eyal 951]

tps? tune?

[lsturbohatch10]

i guarantee its the tune. its too rich, your adding more timing to it with the dizzy. the extra fuel is takes longer to burn. by advancing the dizzy you are causing it to spark sooner. sparking sooner gives the gas the time it needs to explode at TDC

[93delsolvtec]

when playing with the cam timing did you reset the ecu...i would of thought that with higher compression and a cam you'd want to retard timing if anything not advance....just what ive read in past posts....im doing a cam swap right now with a 59300 (z6) so i hope i dont run into this, but im using p29 pistons so my c/r will be a little higher

[93delsolvtec]

the sewing machine noise is due to the bigger lobes and is common

[siregcivic]

i guarantee its the tune. its too rich, your adding more timing to it with the dizzy. the extra fuel is takes longer to burn. by advancing the dizzy you are causing it to spark sooner. sparking sooner gives the gas the time it needs to explode at TDC

thats cool... i was running a p05 converted to vtec with b16 maps tuned for intake header exhaust..

i had a d16z6 intake header exhaus gude gorilla cam and y8 cam gear to advance the cam 4 degrees

never was tuned for the cam.. it idled like a beast had power from 2600-9300 stock head stock valvetrain stock block.. i beat a talon turbo at 16 psi by 3 cars ran a 9.5 in the eight spinning 3rd through the finish line...

its not rally all in the tune.(atleast with na).. is knowing how to setup the car coorectly:TU:

[sir_lagalot]

dragman99: yes, i dont really know how to describe it..it skips, jerks, misses..and a weird ass *blub blub* sound from the exhaust, then the rpm hits 3200 and the engines sound changes as if vtecs kicked in and its perfect from there on. but if i'm in second and i floor it..its really funny.. it just doesnt pick up.. response almost zero till 3200.

gloryhog: no engine mgmt at the moment. its the stock obd2b ecu.. i didnt know i was supposed to tune for a stage-2 cam. i guess i'll get it chipped.

lsturbohatch: what i dont get is, if by advancing its burning all the fuel properly, why is it i get this drop in power..the second i advance the dizzy past stock , i lose about 5-7 whp there and then.

i guess tunings the only way to keep these numbers with the car running properly.

93delsolvtec: best of luck with your cam!

[dragman99]

dragman99: yes, i dont really know how to describe it..it skips, jerks, misses..and a weird ass *blub blub* sound from the exhaust, then the rpm hits 3200 and the engines sound changes as if vtecs kicked in and its perfect from there on. but if i'm in second and i floor it..its really funny.. it just doesnt pick up.. response almost zero till 3200.




no check engine lights?

[sir_lagalot]

no cel nope!

[lsturbohatch10]

lsturbohatch: what i dont get is, if by advancing its burning all the fuel properly, why is it i get this drop in power..the second i advance the dizzy past stock , i lose about 5-7 whp there and then.

i guess tunings the only way to keep these numbers with the car running properly.



my understanding of what is happening is when you advance the distributor, you are moving the powerband into lower rpms. now when you tune, you will be able to keep all of that advance down low, but you can retard your timing up top in the ignition tables in crome.

[sir_lagalot]

i get!.. i'll go with an obd1 conversion next.

[dragman99]

i've never had the zex stage 2 cam, it must be really be aggressive on the low cam lobes. i had the stage 1 in my y8 auto, it was a little boggier, but not anything i couldn't fix with a cam gear adjustment.

[sir_lagalot]

i'm gonna go for engine mgmt. but i'll have to wait till i get retainers because i might as well increase the rev limit when i convert. its stock atm. i'm using stock retainers with zex springs right now.

[Arachnid]

i don't think you got the right cam...cam specing should be in asap. sounds like you got higher stage cam. sounds just like my crower3 before tune. but then again my old zex2 did do the same thing too, right before it drove my valvetrain madd...all in all i will be 98% to say that the p2p sucks ass and you'll need to tune.

[sir_lagalot]

by driving your valvetrain mad you mean?.. because i have to adjust my valve lash every now and then , its ridiculous. its quiet for a week or so then it gets loud on me again.

[Crossroads]

I have the 59300 in my Z6 with 9.5:1 compression and the Comp's springs and retainers. Valve timing is 2 degrees retarded and ignition timing is at 16 degrees. The only time I had any bogging was when my lash was way too loose. My car picks up at 2k in fourth gear. Are you using a timing light when you time it?

And yeah, the ticking is normal. I actually like it now, after 4k miles.

[sir_lagalot]

they had some problem with the timing gun. they just set the dizzy in the middle and tuned with the camgear.

i advanced the ignition all the way yesterday...bogging went way but so did a noticeable amount in power..

[siregcivic]

try leaving the cam gear at 0 and leave the dizzy advanced

[Crossroads]

Your ignition timing is off. Get a timing light that works. :)

[Sexicivic2000]

I am running the comp stage 2 full head package cam gear springs retainers and clips in a y8 and have my gear retarded 3 deg because the grind on this cam is 3 degrees Advanced. 47psi fuel pressure at full throttle OBD 1 p28 ecu, ignition timing advanced a few degree should eliminate that hesitation idling around 500-600 rpm snappy throttle response power off idle to 7900 rpm no complaints. my prior setup was with a obd2 p2p same results still no probs shiting on b16 and b18 s I would also doudle check your crankshaft timing again just to be safe

my setup pictured on the left

[lsturbohatch10]

ya with your dizzy in the middle your its definately not gonna have any power down low. before i figured out my timing light, i had my dizzy set at 0 degrees,(just to be safe when i sprayed) god it was slow. stock ex coupes were out running me. advance your dizzy almost all the way, then retard about 2mm. thats about 5 degrees out.

[Crossroads]

Use a timing light and set your timing to 16BTDC (the middle of the three lines on the crank pulley). Using the position of the distributor itself is a poor way to set your timing and will almost always lead to incorrect timing. Don't try to use your distributor to make up for not getting your ECU properly tuned.

[Arachnid]

it's not the dizzy it's the ecu being gay...and by "driving my valvtrain mad" i meant that the cam wore down itself and the associated rockers and somehow i ended up with half a retainer....i've seen someone post pics of what i'm talking about but i don't remember where.

[Crossroads]

If the base timing isn't set correctly the ECU won't know what's going on and will try to adjust itself accordingly.

Comp's cams are supposedly really hard on rocker arms. I'm going with a Bisimoto Level 2 for my next cam.