Thread: Went to the dyno last night, tell me what you think

Evlnxr. I have found that 20Vs love to run lean, If you can keep that blue line closer up to 14 to 1 there will be alot of power to be had.


You can see on your P12 chart where you have 2 rich dips the power drops and then goes back up when it gets lean again. The RPMS being 5500 and 6700 RPMs.

If you look at he S4 one you will see it is alot leaner. This 20V with its higher knock point likes 13.8-14 to 1 mixtures.

Some leaner tuning and switching the cams at 6600 or so should make for a much better power curve.

Please note that the switching point for the 20V from factory is going to be diffrent because they also use the Electronic TB to regulate air flow. Thats why the damn power curve is so flat from bottom to top.

Anyway great job. Hope to see the new tuning figures out.

sorry i ment rich, at 80-90kkm/h you fuel nearly hits 11:1 this is also where you power dies in the arse. i think your mixtures need some attention around this area. you might be able to get rid of that flat spot

When you change the cam switch point, are you following with changes to the timing as well?

http://www.youtube.com/watch?v=jZHl5N43WUU

Wow that thing pulls hard down low. Would love to see a video on the street.

Definitely try moving the switch point up a bit.

Keep up the hard work.

Dudeman

Evlnxr

How do you switch your cams? Do you go exhaust first then intake or do you go intake then exhaust?

The reason I ask is from your comments its seems that you switch exhaust first then intake.


Nissan Switches the intake cam first then the exhaust.

Switching the intake first brings up the torque which Nissan seems to do at 5000, then at 6500 they switch the exhaust to pick up the HP. I think that is correct.

I know for a fact that if you switch both cams together on the 20V you need to do so in the 6200 plus RPM range.

IM trying to find a straight answer on which solenoid is which, it the one closest to the the head the intake?

yes the solenoid closest to the head switches the intake cam.

this is from looking here:


Purple: oil feed from block
Red: oil from closest solenoid to head going to inlet rocker shaft
Blue: oil from furtherest solenoid going to exhaust rocker shaft
Pink: oil bypass back to head.

nice vid. lovin' the results too

ok, interesting, thats the way ive got my mss hooked up, unless the ports on the 20v head are different, which is unlikely. I had it hooked up the wrong way a while ago, and interestingly it did not sag when i switched the exhaust at 5000 like it does atm with the intake.

I'll wait and see tho, as i think the tune has gone way off for some reason. I was massivly lean on the 1st dyno run, fortunatly we had the tune on the laptop, and borrowed the shops chip burner to add some more fuel in.

Retune on Thurs, maybe dyno again next week.

Also, vids from the rest of the dyno day.

Dyno vids

Part 1
http://www.youtube.com/watch?v=QkasnXg4BEI

Part 2

http://www.youtube.com/watch?v=zbld774KC1U