hey guys, im on the quest of beginning my build, but i was wondering if putting p29's in my bottom end with a stock obd-2a ecu will mess things up, i know its a considerable jump in compression, i can put a thicker headgasket on if i have too.....i only need it to last a month or two till i can get a vafc, and no im not converting to obd-1 thanks, i need this asap

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by young noob &raquo;</TD></TR><TR><TD CLASS="quote">hey guys, im on the quest of beginning my build, but i was wondering if putting p29's in my bottom end with a stock obd-2a ecu will mess things up, i know its a considerable jump in compression, i can put a thicker headgasket on if i have too.....i only need it to last a month or two till i can get a vafc, and no im not converting to obd-1 thanks, i need this asap</TD></TR></TABLE>

If your sticking with the stock obd2a ecu, your only option is going to be to retard your ignition timing via distributor to control ignition timing.

You could also look into a piggyback tuning solution that can control ignition timing.

Why don't you want to convert to obd1 ?
Its all plug & play....

 

i just had this same problem in my 00 Si with CTR pistons. with a thick head gasket (.062") the stock ecu works fine. with a stock head gasket, I have to run obd1 and adjust in more fuel on the maps otherwise it is way too lean.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mtber &raquo;</TD></TR><TR><TD CLASS="quote">

If your sticking with the stock obd2a ecu, your only option is going to be to retard your ignition timing via distributor to control ignition timing.

You could also look into a piggyback tuning solution that can control ignition timing.

Why don't you want to convert to obd1 ?
Its all plug & play....</TD></TR></TABLE>

is there a piggy back that controls ignition sorry for the noob question? i know vafc controls fuel......and yea im thinking about running a thicker headgasket, then switching to a regular oem one when i put the pnp and cam'd head on.....with supporting tuning of course

and i don't want to covert to obd-1 caz i like a challenge and being different by staying with the obd-2, but also when ispection and all the bs comes around, i wouldn't pass..............

 

bump

 

KABOOM. say goodbye.

 

c'mon guys that doesn't help, im going to run premium fuel, give me some advice......

 

If you MUST stay obd2..

A piggyback with ignition control is your only true option other then tuning via distributor adjustments & a fuel controller only.

Going obd1 would be plug & play. When inspection time comes, simply plugin the stock ecu. As long as they don't do any wide open throttle inspections, you will be fine.

 

well what happens when i need to drive to get inspected thats like 30 min. away, and i have to drive with an untuned stock ecu? also, does any1 know of any piggy back ignition controllers?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by young noob &raquo;</TD></TR><TR><TD CLASS="quote">well what happens when i need to drive to get inspected thats like 30 min. away, and i have to drive with an untuned stock ecu? also, does any1 know of any piggy back ignition controllers?</TD></TR></TABLE>

Drive with the with the chipped ecu until you get close to the DMV, pull over and throw the stock ecu in. Get car tested, leave and throw in the chipped ecu.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Gong Show &raquo;</TD></TR><TR><TD CLASS="quote">

Drive with the with the chipped ecu until you get close to the DMV, pull over and throw the stock ecu in. Get car tested, leave and throw in the chipped ecu. </TD></TR></TABLE> the only problem with that is you need to set some of the readiness monitors on the ECU and each time you swap ECU's, they reset. you have to drive around for a few minutes to cycle through some driving situations to set the monitors or else the emissions testing system will automatically fail you. if you have an obd2 scan tool, you can do this quite easily in a matter of minutes (but you will need an uninterupted stretch of road for at least a mile where you can get up to 55mph and hold it for a good minute to set one of the monitors) .

i say use a thick *** head gasket with the stock ECU to pass emissions and call it a day. then after you pass, go nuts with the mods.

 

Stock ECU is gonna have too much timing with that high of compression.

 

well i am currently building the head as we speak, i won't put it on until i have the supporting tuning modifications and after my emissions test in july, and it will have a camgear, so i don't need the extra compression really until i put it on, which i will use an oem 3 piece, or maybe 2 if i decide to get a little crazier, my last questions would be what sized headgasket should i use to also have a little fun with compression, what i mean is i want to bump compression a little, maybe around 10:1 from the factory 9ish:1.......just to get a little peformance from all this work and sweat until the fun stuff starts...................

 

I ran p29's in my old setup on stock p28 map for over 2 years and beat the **** out of it everyday, Upon teardown everything internaly was perfect.
BTW I only ran 93 oct.

Dont be scared of a little compression.

doen the obdII ecu throw more ignition out or am i missing something?? EDIRhttp://i39.photobucket.com/albums/e182/crixzc/na.jpg
EDIT: assuming you have a y8 ecu


Modified by spun Vtec at 9:18 PM 6/30/2007

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by spun Vtec &raquo;</TD></TR><TR><TD CLASS="quote">I ran p29's in my old setup on stock p28 map for over 2 years and beat the **** out of it everyday, Upon teardown everything internaly was perfect.
BTW I only ran 93 oct.

Dont be scared of a little compression.

doen the obdII ecu throw more ignition out or am i missing something??</TD></TR></TABLE>

im not sure man about the ecu......my s/n owns me .........this is my first build, so its a learning experience

 

plug and play? No.

Plug and pray is more like it

 

to update, i just sent the block to get bored out for .040 over pistons, i will be running 92 octane, and i bought a thicker headgasket from tunertoys to lower my compression to about 11.3:1 or 11.8:1 lol i am getting different specs on the d16y7 combustion chamber, so depending on whether it has the dimension of the d16z6 i will have 11.3:1 d16y8 specs i will have 11.8:1, so i am thinking with a little moving of the distributor, i will be just fine with this set-up.........comments welcome thanks again

 

not gonna be good enough, it you retard the timing enough so it does knock, the engine will be lazy overall.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mista Bone &raquo;</TD></TR><TR><TD CLASS="quote">not gonna be good enough, it you retard the timing enough so it does knock, the engine will be lazy overall.</TD></TR></TABLE>

do you mean retard enough so it doesN'T knock? and also, what all would be needed then to get this running strong.......without going obd-1..........

 

short rope and a tall tree

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mista Bone &raquo;</TD></TR><TR><TD CLASS="quote">short rope and a tall tree</TD></TR></TABLE> haha

Your going to need to go obd1. suckit up, buy a conversion harness and obd1 ecu. If you dont have a 4wire o2 just get an innovate lc-1 It is a wideband and gives the ecu a stock o2 readout.

Its not going to run right without the obd1 and some tuning

 

ok, i understand what you all are saying, but why can't i retard timing to stop knock, and then that will be too much timing and the car will be "lazy"? what is the difference between retarding timing with an obd-1 car, and why doesn't it make it lazy? also, what is a safe bump in compression that i can run with 92 octane and stock ecu? i still can get a bigger hg and play will compression.....also aren't there tricks to limit knock? can't i polish my pistons, that will lower compression a little caz of the material taken off, and i have heard polishing lowers the chances of knock correct?

 

bump

 

the motor is gonna require a different timing curve along with a different fuel map.

Your gonna have to be able to remap the ECU or your gonna screw up alot of parts.

 

even with 11:1 compression? with 92 octane? and polishing the top of the pistons?