I just wanted to check with some people regarding their cam gear installation. I have a vishnu stage 1 signature system installed on my evo for about a year. I just recently purchased a pocket logger to see if I could improve on the basic tune any. I logged timing with the base map and 14 degrees on timing was being pulled with absolute timing bottoming out 0 degrees at between 2500 and 3750 RPM. I know that the timing should not be pulled in that area. Therefore, I am trying to investigate whether I have a bad batch of gas, incorrectly installed cam gears etc. etc. Anyways, I started looking at the cam gears and I realized that with the cam gears lined up on the valve covers timing marks, the crankshaft timing seems to be a 4-5 degrees BTDC. I started to think that my gears were installed one tooth off. However, one tooth would be approximately 7.5 degrees difference not the 4-5 degrees that I am seeing

The EVOMOTO guide for cam installations states that it is not uncommon to see 2-3 degrees BTDC, but I would like to get some responses from other installs to see if any other people are seeing the same thing.


Thanks
HiVoltEVO8

 

Ok, I am probably completely wrong on this, but ... where/how are you measuring the crankshaft timing? I assume by BTDC you mean retarded timing, which in turn would lead me to assume that your camgears are installed correctly and set to -5/-5, which is generally how a stage 1 is setup (read: stock camshafts). If you have the same Vishnu camgears that I have on my car, then the TDC mark is one tooth off where the 0 mark is on the cam gear adjustment (contact Vishnu to get an install guide with pictures) and it ends up looking a little weird when it's installed correctly.

l8r)

 

I am reading the position of the crank shaft when the gears are straight up (i.e. lined up with the notches that are in the valve cover.) I am using the tooth on the cam gears that has been marked with red paint (Vishnu gears). I am also aware that the timing mark on the gears is about one tooth off from the zero mark on the adjustment scale. However, this should not affect the position of the cam timing mark in relation to the crank. The 5 degrees of cam adjustment is in relationship of the cam to the cam gear. Therefore, the cam gear timing marks should still line up at TDC on the crankshaft and not 5 degrees BTDC on the crankshaft. Is my thinking flawed??????????

 

No you are correct in what you have just said....how do you know it is 4-5 degrees of crank timing?...If it had jumped a tooth it would be at 15 degrees of crank timing...and because of the direction of rotation it would more than likely have advanced it
Remeber that the crank turns at twice the speed of the gears...it is not uncommon that when the evo engine is set at TDC that the crank mark will position itself a few degrees before the TDC mark on the cover...I see it all the time
Do you have an Xede/Xedeflash with your stage 1?
or is it an Xflash?

 

Here's my Stage 1 log if you want to compare....

 

I think what you see is normal. The ECU will pull timing when load is high and boost is building up, then ramps up back again. Xede map will pull from this, too bad we cannot log the final timing

This is a log from my stg1+



This wacky one was from my GTI. Looks like it was riding the knock sensors.

 

Well, I have not used a degree wheel or anything as elaborate as that. I am just using the timing marks on the crank pulley/dampener, the crank pointer and the cam timing marks.

I am beginning to believe that I have everything installed correctly and that this is normal for the ignition timing to be very close to 0-1 degrees BTDC at 3500-4500 rpm. Especially after looking at everyone elses timing charts. Mine look very similar.

Oh, I am running an XEDE only. I do not have an XEDEFlash or XFlash.


Thanks for your help.

 

Jorge T,

Thanks for the graphs. They put my mind at ease. Mine look very similar. Therefore, I think that I have everything installed correctly.


Thanks again.

HiVoltEVO8

 

FYI, my car reads 4-5 degrees btdc.