At our most recent dyno day we dyno'd and tuned a car for one of our customers, Fast Freddie. He has an 05 with the normal mods (no cams, never had cams in the life of the car). It had a roadtune on it from a previous tuner but Freddie wanted us to take a stab at it on the dyno and see what we could pull out. I pulled the ROM, saved it, put the immobiliser on our base Knocklight and got ready to go.

We decided to baseline the car to see where it was. 302/280 to the rollers on Bob's (Drift Office) dynojet 424. Okay not bad for a roadtune, it had a few things I didnt like (lean spool was on and went pig rich above 7k) was a stock type ROM, etc. Loaded our map on the power dropped BAD. AFRs were good, but it dropped to 258. I was WTF as was Lucas so I looked at the last map and noticed that the timing numbers were HUGE. Like C16 racegas numbers on a stock turbo on pumpgas. This didnt make sense why the car lost so much power and why it hadnt blown up previously. There hadnt been any knock on the baseline so I started adding timing back in and ended up at 311/308 before heatsoak had done its job in the 90*+ dyno cell.

Now here is the question: Has anyone else run into a car that has never had cams that acts like the CAS is out of phase? We did have an 03 that had had cams and was back on the stockers do exactly the same thing so we figured it was a CAS problem on Freddies as well. He checked with the previous owners since he is friends with them and there were never cams installed.

Here is a screenshot of what the timing looked like:



The car has the normal mods minus cams, TBE, intake, pipes, etc and is running 23-24 pounds controlled with a Profec SpecB. Timing at idle is correct according to the log (which I do not have on my laptop currently) that I had. I will relog the car prior to the cam install to reverify idle timing and then post after the cam install.

My general impression is the car acts like it is low compression and loves boost. It doesnt smoke, idle rough, or display any bad drivability characteristics.

Here is a copy of the dynosheet. The drop at 6k is some heatsoak knock that didnt reappear on the street after the car had cooled down.

 

I assume it doesn't have adjustable gears on the stock cams, does it?

 

Stock cam gears.

The CAS out of phase is just an idea. We have not had a chance to really look at these cars and see why there maps are this way.

 

Hey JB...

I somewhat experienced this same thing last weekend. I pulled a guys map on the dyno... looked her over and the car looked as though she was tuned for C16 all the time. Im talking timing in the 13's and 14's at peak and over 18 up top. I was amazed it didnt blow as well. I decided to go ahead and run the car on this map for the first pass after talking to the customer who said his car seemed to drive really well with no performance issues. By 4000 RPM i hit 17 counts of knock and killed the run. I wonder if the tuner was the same. The guy here doesnt know who the previous tuner was.

His car was acting funny as well. Almost like the timing belt was off a tooth. His idle was terrible and nomatter what i did to it, it would not idle smoothly. It only had 272's in there as well. Ofcourse the standard turn on the A/C dying thing which nomatter what i did would not be corrected either.

Is this guy the original owner or has he had anything replaced under the Valve cover ? maybe for whatever reason the piece was taken out and reinstalled 180 out ? That is a tough one, im still lost on the Map timing thing

 

Well the car had 0 knock on our base line pull and only got knock after about our 8th pull and turning the boost up. (5cts at most)

The 2nd car like that just seemed real low on power for the mods. Did about 20cars that weekend so we know what the # should be for given mods. We started adding timing and gained 50hp till we hit a few counts of knock and the hp was right ware it should be for mods done. The car idle and drove great.

This is Lucas

 

I am sticking with the hypothesis that I got a freak of nautre from the factory... but that is just me...BTW Lucas, I turned the first gain setting on the profec b down to 14 and turned the second up to 20 today, and boost seems to be holding a lot better at 23.1 psi instead of hesitating. I was telling Aaron that I was getting some knock on the NLTS cause I hit 25.5 psi the other day on a "closed course". Freaked me out a bit when my boost controller started beeping at me and I checked the memory and it read 25.5 LOLZ It was a bit heat soaked at that point too... Also am I going to need injectors with the cams or not... stockers are good to like 400 hp correct?

 

the stock injectors will be good on stock turbo, Who did the original tune?

 

Andrew (evoRS06) with no wideband... hence pig rich

 

It was Andrew. Decent tune honestly, we just found more torque and some other issues is all and got it on the knocklight. We did make 319 on an earlier pull but the powerband was pretty craptastic so we tried again.

Back to being Aaron

 

the only reason i asked is that he might have an idea of what was going on

 

Nope... he was really surprised that it was taking the amount of timing that it was especially up top... It was seriously really weird...

 

spit it out

 

Jason, I think he meant that maybe Andrew had an idea of what was going on.

 

i kinda caught that..... i was hoping he had some inside knowledge as to what he was referring to

 

Am I reading that AFR plot wrong or is it running over 12 AFR on pump gas?

And is this dyno/afr plot after you "retuned" it or?

Have you checked the cam timing? Compression and leak-down?

I've seen a car take more timing than normal once, alot more. problem was that it didn't really make power with it as the head was over-scavenging, which is why it could take so much timing.