but u are right tho. that dyno shows nothing different other than the mystery lost in power. I thought the powerband would have look different above 5k but it doesnt

 

Could the knock sensor be pulling timing even if I am not getting a knock sensor code? I checked codes after the dyno and I am just showing the usual stuff....no knock sensor code.

 

Did you check timing??? Install a resistor... Check timing, then run the KS and see if it changes....

 

Will an OBDII scan tool showing timing? I don't have any sort of fancy engine management. I only have a JWT ecu and a VAFC-II I was not in the car during the dyno. Since I was not throwing a k/s code I assumed I would getting all of the timing I was supposed to. The car was heat soaked....but it was heat soaked the time before too....so I don't think that's it.

 

You would have to use something like the uprev cypher to log the timing. Sadly. I can check mine through datalog on my utec using jeffs software, but again, thats not an option with what you have.
We have been having a problem with one of the cars ive been working on, and oddly enough to test the theory He removed the knock sensor from its location and wrapped it in a towel. in doing so the car roared back to life where it had a flat spot prior from 1500-3500 rpm. And I say that to say that we did not have a knock sensor code at all.

 

I keep a resisitor in the console. I should have swapped it in. I may try it in the next few days to see if the butt dyno can notice a difference. The knock sensor in the car is new, but my car may vibrate more than the average maxima causing the knock sensor to detect false knock and pull timing....not really sure.

Does the car you are working on have aftermarket cams?

 

Wow... Was this 2 different dynos?... Calibration of dyno i guess... Lost 13whp and gained 2mph in traps... Thats contradicting lol..

 

exact same dyno

 

I put a 470k ohm resistor in to the knock sensor circut this morning. They car is running well and pulling strong. I cannot tell if that's what the problem is or not. I would like to make it back to a track before the season is over before I go back to the dyno, because it's a cheaper was to figure out if I got my power back.

 

why did the rpm cut off sooner? I know this sucks, but the best way to do this is to dyno as is without the ssim w a proper afr. swap the manifold on the dyno. dyno and tune it again and compare best results. thats how i did it. cost me an hour on the dyno but this way you can truly compare apples to apples

 

Very nice numbers.

 

Initially I lost power with the SSIM when it was the only mod difference. Needed some tuning/manipulation/supporting mods to gain it back.

Completely different situation being an auto 5.5 g with functioning VIAS (No BOP), but semi comparable.

 

I hear what you are saying, but the Ssim did not work well for me. I don't have anyway to directly control timing but by looking at my losses I'm not sure it would have mattered. I know ajcools brother also lost power with the Ssim. Maybe it has something to do with ditching the variable cam timing when you swap a fourth gen...who knows

 

Hey Carson, what clutch are you running? I'm wondering if a relatively new OEM 5th gen clutch will handle 260+ whp/wtq.....

Did you ever put the knock sensor back in? I'm also wondering if I should just put a resistor in place of the KS in the 3.5 I'm going to install as a preventative measure.

 

ACT 6 puck sprung clutch, I think its rated for 400 some odd foot pounds...don't remember right now. You need to remember my car was put together with the supercharger in mind...some of the parts I have installed could be considered over kill for just an n/a engine. I personally would not use a 5th gen clutch. Not sure the tq rating for the fifth gen clutch but it was put on a car that put out about 200ft/lbs, and you would be putting it on an engine that is rated over 250ft/lbs out of the box. If I were in your shoes I would do the ACT solid disc clutch, I think it would be a good match for you. I had it on my car when it was 3.0 supercharged and it never slipped and was not too hard to drive, the pedal is a little heavy but I like it that way.


I am still running a resistor, I need to plug the k/s back in...I keep forgetting to do it. I only did the resistor mod because I knew my car was dialed in well and did not want to take the chance of the car pulling timing while I was at the track. Since my idle is not a smooth as a stock maxima and also doing a burn out can be a little bumpy, I did not want the computer to pick up any perceived knock. I would suggest running a knock sensor at least until you get everything figured out.