JHM Over sized Crank Pulley

B8 S4
#41

Mike, my brother was gone by the time I got to his shop so I’ll get the measurements Friday or more likely Saturday…

Saki, I think that’s about right…

I think we all need to remember eaton is a big supplier and rates things to perform for x miles at x rpm’s and similar to Audi or many other car manufacturers is conservative for various business reasons. Again, I think the mod will shorten the life of the blower but for me that’s really not a big factor. Just my .02

So picked up the car… Way too much traffic and it’s going to rain anytime now so I just headed home… Didn’t even bother to hookup the laptop. Did run through a few gears but not at wot… Blower makes a much higher pitched whine that’s for sure… I’m not much of a seat of the pants guy so I won’t make those judgements and I really didn’t drive it hard enough to tell… I’ll test tomorrow eveining when I get home from the office since it’s about to rain… Assuming nothing looks goofy log wise and the car drives well I’ll hit the track this weekend… I’ll be running race gas this weekend…

#42

One interesting fact I saw mentioned on az is that the stock map sensor maxes at 2.5 bar. Aren’t we getting pretty close to this?

#43

That’s what…nearly 22 psi at sea level? Thought you guys were seeing 18-19 stage 2?

#44

I don’t think I’ll be making that much absolute pressure even running in a mineshaft… Lol. I guess I’ll find out soon…

#45

Everything install okay?

#46

So just went and did a few early morning runs to log some data…

Temp 48
BP 30.2
Humidity 82%
DA 750ish…

So left the house and drove about 5-6 miles to warm the car up and once the oil was about 160 I did a few runs… Given it was on the street most were only a few gears and I tried a 1-2 roll 2-3 roll, 3 gear punch and I did try one launch put the car wheel hopped very bad given the cold ground so I got out of it and then back into it…

So first one my IAT’s were in the teens and 20’s! lol Gotta love cold dense air! I rolled out of the light and punched it at about 2500RPM and the car hit hard and pulled very strong… Unfortunately, I bypassed 6% of the boost up to 6000 RPM and then about 10% to redline as I was up against the max targeted boost the whole time… I’m 100% sure this is a result of the pulley as I’d never hit the target before which makes sense… Timing was good on the mid and upper 20’s(this is on 104 tune and GT260+ fuel) Little retard in 1 of the 2 cylinders I’ve logged but nothing major. Air mass was nearly 1500 by redline…

Second one was a punch from a roll in 2 and similar results from a bypass standpoint. Tiiming was similar with a little less pull and IAT’s were in the mid 30’s by now… Both target and actual boost were higher by about 60hpa which is because I was in 2 not 1.

Third one basically same results with no timing pull, little higher target and actual boost again given the gear and IAT’s were upper 30’s to very low 40’s… hpa was up about another 50 points…

Fourth was from a dig and as mentioned I got out of it and back into it since I was hoping violently… lol The encouraging thing here is I had almost no bypass until I got out of it then a ton and then when I got back into it was 3-4% until 6000RPM than it got to about 9% to redline…

So overall getting some bypass but I kind of expected it but everything else seems to be ok on these few short passes… Safe enough that I feel ok making some actual passes and going all the way through 4th. Still not sure if it’s a big event at Thompson today but I’ll probably just bite the bullet and go anyway and at least make a pass or two… Will just be a ton of cars, lots of waiting(which the car doesn’t like) and probably only 2 passes before racing actually starts… If not Sunday should be better but warmer so we’ll see I might do both days…

If anyone wants the logs let me know and I’ll be glad to email them as I have no problem sharing…

Jeff, Have you logged you car in great air and are you getting bypass at all?

#47

yes… no issues… thanks

#48

Cool thanks for the update

Still likely means you’re adding power (as expected) and the increased boost isn’t creating a heat problem (on a few pulls anyway) .

All around good deal.

Would be interesting to see the differences between your 104 tune and Jeff’s. I. E. What is max requested pressure on each.

Also I wonder if Jeff bypassed any boost as he ran in the summer.

Do we know if Jeff has a special sauce tune from giac? Also, where did Auditude3.0T disappear to. He was pretty jacked 2 weeks ago about his dad’s car, then that died on the vine. Never heard if he and Austin also worked on this dual pulley approach. Might explain the newfound burst of ET and MPH he experienced on those passes he made (1 at strip and 1 pbox)

#49

Thanks Saki! I’m excited just to play again since there are some changes! lol

I’d agree and will see what the trap speed says, just hope the car shifts correctly… If not I think I’m going to have the dsg tune removed and just run stock.

I haven’t seen Jeff’s logs so I can’t comment unfortunately, there timing is usually a degree or so higher but the v3 is probably more in line.

I don’t think he has a special tune but not positive… No clue on Pete either but Austin was at the track and it ran mighty good, so who knows…

Not bagging on Pete or Jeff but unless I’m asked by APR to not talk about something I’d rather share, as I’m not getting paid to try and set records so I enjoy the discussion and trying to learn but to each their own… I’m sure Jeff will let me know whats up at the end of the season and as always I wish him the best!

#50

Mike, Double checked the stocker last night… Brother measured it multiple times and I did for myself… 6.385 everytime… His guess is it’s probably truly 6.375 w/o the coating… I could probably take it to work and have our lab measure coating thickness but no way it’s .16…

#51

Thanks a bunch man. I have updated the blower speed thread with the new figures.

Mike