Let's play "Guess that dyno number"!!

B6/7 S4/RS4
#1

I’m slightly afraid of posting this here but oh well. ;D

Taking my B6 MT S4 to a Mustang dyno today and I wanted to see if I could get some output predictions.

Mods:
No precats, stock cats still intact.
Stock catback
JHM LWFW and Stage IV Clutch
JHM 91 Tune
K&N Drop-in
Fresh Oil
Fresh Plugs

Car has 62k miles and had a full timing component overhaul and 40 new valves installed about 3k miles ago (thanks to awesome B6 S4 cam adjusters).

Oh, I’m also in Salt Lake City, Utah. About 4500 Ft above sea level.

I know that I won’t be setting any records but I want to get a baseline before future mods etc.

#2

And before people say “dyno numbers don’t matter”…

I realize that no dyno sheet really means much. I just figured I could do this while I wait for the track to open. Then I can compare my TQ/HP numbers with my 1/4 and see if I need driver mod :-X.

Although, in defense of dyno sheets, I do feel that they can provide some useful information (power/torque curve, shift points etc). I think that dyno sheets and 1/4 mile times should go hand in hand.

For instance, I’ve seen forced induction cars that switch from a medium turbo to big boy turbo and add 100hp on the dyno but lose 1 second + in the 1/4 mile due to shifting the power band so high in the rev range (a la the B5 big turbo guys from weeks around here).

Which reminds me of an old joke that could work for the B5s… “What do 700, 800 and 900 HP Supras have in common? 13 second 1/4 mile times…” ;D

#3

Haha, funny joke. The punchline for the b5 is different though… It is 12 second quarter mile times because they at least launch reasonably well.

I will say something insanely bad.
245 whp 230 wtq

If the dyno is a shop that mostly deals in non audis, take it lower as they’ll be hatin’.
235/220

If the dyno is an Audi shop but they are lrimarily b5 s4 focused, even more hatin’ and lower still
225/210

#4

Sir… how dare you insinuate that dyno numbers can be so easily altered!! :o Haha

Honestly, I’d be super happy with 245/230.

I was thinking in the 230-235 range.

Not sure what the shop’s focus is… they have photos of a B5 S4 on their website. Being that they are in SLC, I would imagine that they focus primarily on Subarus/EVOs because they are the koooolest!

#5

And I will be posting the sheet later today… glory or shame, most likely shame.

#6

Oh the shame…

#7

Bang on expectations. Typical at altitude for these cars all motor.

Any other results from the dyno for other s4 4.2 or rs4 cars?

#8

Remind me to never move from sea level…

#9

For the lazy:

http://img341.imageshack.us/img341/7886/gratdyno.png

Look how flat that TQ curve and how early it comes on.

And saki’s advice to me to shift at 6600rpm at the 1/4 - bang on.

#10

lol I used to always think that when I saw stuff from sear or johnnyalqaeda who lived at mile high Colorado altitude.

#11

Nope…paperishwhatever says you should redline your car in every gear regardless of where your powerband drops off…he is a skreet race king

#12

Thanks for the actual upload, wasn’t sure how to do that.

And yes, moving from Phoenix, Arizona to SLC, UT has made me realize that no car I have will ever reach it’s full potential here. You’re just behind the curve (pun intended) no matter what you do.

According to my/Google’s calculations, I lose 40-45 crank HP from elevation alone. Which leaves 22%-ish drivetrain loses.

Add 100 crank HP from a JHM supercharger and 50 or so from catback/headers/intake manifold and I lose 58-67 at the crank in UT. Sad really. I guess they only benefit is picking up huge gains when I take a road trip to Las Vegas?

#13

If this thread is any indication of how hateful the altitude is than I am guessing that you don’t even break 200 horsepower.

The OP in that thread has a RS4 at less altitude than G-Rat but probably was heat soaked to hell. He only put down 254 whp as my stock power S4 at sea level did 260 whp. I am with euroswager that higher altitude sucks!

#14

Very true. Thanks to the dyno I can see my 6600-700 rpm shift point for when I go to the track in a month or so.

Speaking of the track, the dyno operator informed me that the dyno had a built-in 1/4 tester and asked if I would be interested. I said “let her rip” and showed him how to use the JHM LA. I was actually quite pleased…

Distance Time Speed

60’ 1.94 31.84
330’ 5.93 59.59
660’ 9.28 74.73
1000’ 12.15 86.42
1/4 Mile 14.59 92.96

No idea how accurate it is… I guess we will see in a few weeks.

A few other things to note.

When I pulled away from the shop, I noticed that my RPM was holding really high between shifts and the idle was around 1200-1500 RPM. I pulled over and popped the hood to find that the vacuum hose (from the PCV) to my passenger valve cover was completely off and sucking in air. The problem is that I have no idea if this happened on the dyno or not. If so maybe that’s why I didn’t see any gains from the few bolt-ons that I have.

Plus the hood was closed and ESP was on… not sure if that comes into play at all.

Just thinking out loud at this point.

#15

ESP could be an issue, not that you can completely defeat it. Always a bummer to not know if something was awry on the dyno or after.

#16

Those quarter mile times don’t add up so I wouldn’t put much thought into them

Also do not (DO NOT) use a launch assist with esp on. MUST MUST MUST turn it off.

#17

My bets are 235awhp…but god damn you are at a shitty altitude for power from a NA car…any car for that matter

#18

G-rat, you’ll be shifting at redline in at least the first couple gears, you will be losing out if you shift at the power peak. If you have time, take you gear ratios and plot your torque curve multiplied by each gear. When you’re done you should have something that looks like this (stolen from the web):

http://members.roadfly.com/jbgotm/gc_plot.jpg

You should shift where the lines cross, i.e. when the torque x gear ratio in the next gear is equal to the gear you’re in. Most cars have optimized shifts at redline in at least first and second, if not third as well.

There’s another factor for faster ETs which pushes the shift points even higher than the chart above. Because during your shifts you’re not accelerating, you want your shifts to happen at a faster speed if possible, minimizing the time spent not accelerating at a lower speed. i.e. if you shift at 85 mph instead of 90 mph, you will spend 0.4+ seconds at 85 mph instead of 90 mph, which will be marginally slower…

#19

I concur redline away. I don’t have a v8 s4 my powerband keeps climbing all the way to 7200 rpm on my car, you see that on every stage manual B8 S4 dyno graph.

#20

If bangoman were to elaborate, first gear is fine to take deeper on the b6/7. Second and third though for this mod list shift at 6600-6800max.

These are important to achieve faster times. Graphs are fun until you realise that you’re slower because you listened to a graph.

The reason I shifted where I did on my similarly modded 4.2 S4 and told the same to bangoman is because some very fast people told me where they had the best results after literally hundreds of passes at the strip with this platform and more performance and acceleration testing than anyone on earth has done for the 4.2 cars. By a multiple of ten. Those people are count vohn, bertworks/dan@jhm and Jason Harbinson/ jaybquick@jhm.

So g rat and the rest of you… You can decide: Listen to the B6/7 S4 experts, or listen to a chart toting b8 owner whose goal posting here was to try to undermine something I said. And his pet who is here to back him up.