Hey guys :
i recently went to the workshop to check my timing since i don;t have a timing gun , they advanced my timing from 14 to 18 , the low end and mid range feels better , but i flet a loss power top end, it just doesn;t pull as hard as before, the fuel i'm running is 98 octane . my motor is 98 spec jdm b18cr with AEM CAI + customer b pipe + spoon n1 cat back, going to drag next week, last time when i went there with ignition timing at 14 degree, i hit 101.3 mph and a pretty good time for a **** 60 ft time+ **** street tyre. so i need some advice here, do u guys think my car will be faster or slower? should i retard the timing back ? Also for some reason , my idle stays at 1100rpm when it warmed , turned the screw al the way in doesn;t help at all . cheers

 

The spec is 16 degrees -/+ 2 degrees, so your on the far side of the spec, did he jump the SCS connector and time it with the engine fully warm?

 

You really would not be able to feel a 2 degree advance. Also by advancing it, it should be a little slower in lower rpm's and better at higher rpms. Unless you went to far. Jump the connector also. It doesn't matter much but it might add or subtract 2 degrees, so you could be at 20 or back at 16. Also reset the ecu when changing timing.

Check your throttle cable and see if there is a little play in it at idle.
Put your thumb over the idle screw and see if you have a vacuum leak from it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">You really would not be able to feel a 2 degree advance. Also by advancing it, it should be a little slower in lower rpm's and better at higher rpms. Unless you went to far. Jump the connector also. It doesn't matter much but it might add or subtract 2 degrees, so you could be at 20 or back at 16. Also reset the ecu when changing timing.
Check your throttle cable and see if there is a little play in it at idle.
Put your thumb over the idle screw and see if you have a vacuum leak from it. </TD></TR></TABLE>

r u sure about that, i surely felt the other way around, yep, he used timing gun , also my friend's jdm type r motor is like that too, not sure why though

 

Yep, I mean yes. I have been messing with my timing for a while now. It might be the computer adjusting it that way for you. My 88 might not have all the bells and whistles the newer ECU's have.

The ECU assumes the timing is at spec and it handles everything as if it is correct.
It might be trying to advance it more than needed and that is why you are experiencing a power loss at the top end.

Just keep adjusting it a little bit at a time and see if you recover your top end.
I find a good hill to run up. This increases the load on the motor and gives you a more accurate feel of your power.