Skywagon good for you. Get those time slips up and post those videos. The logs will be helpful and I’m really interested to see what Primetime finds.
As for boost. Don’t go off your p3 go off the provided information from the actual log of the cars oem sensor. That’s what the car sees and that’s the same reference that the ecu pulls from. You can compare for fun but always default to the oem.
Understand and thanks. It’s windy rainy and cold here. Will have to put off logging until tommorow. Hope to post videos tonight. My ICloud is a mess, poor operator technique.
Skywagon can you see the value now in posting this information. I think we can all see the slips where you spun and the car early shifted. To help you see what runs the spinning effected your runs you can simply take note of the 1/8th mph. That should help show the little effects of spinning on most runs. There are a few runs that were effected badly but the slips point to them. Your car is definitely dieing up top.
One thing I think we need to all get on the same page about is what we consider the correct 1/4 mile benchmark to analyze how Sky’s car is running.
Sky, I know you think trap speed is irrelevant, but someone needs to explain to you why this is what you should be after. I’ve seen Saki do a pretty detailed explanation, but maybe it is so detailed that the core argument is being lost?
Obviously a higher trap speed means a lower ET, correct? I think I understand what he wrote. Weather awful for logging. Hopefully tomorrow?
Yes sir…tomorrow?
Slips up. Thanks
I agree with this 100%, and it’s a conclusion not many others have arrived at. It’s a very mild tune, so much so it was once offered with a warranty because statistically it would have the same failure rate of a factory motor.
I use REVO for the road course. I only ever wanted it to do one thing, which is not cut my power at 5200 RPM like stock does. Even when I was stage 1 I had the APR CPS. Keeping the engine cool is the 2nd most important thing. I really don’t need it to make the fastest 1/4 mile in the world. I need it to do 100 pulls to redline in 25 minutes without heat soaking. Ideally I want the performance on the 100th pull to be close to the performance of the 10th pull. You might not get this with the 1/4 mile because the car is only moving for 30 seconds, then it’s sitting in the paddock again. On the road course the radiator and heat exchanger always has 80-120 MPH of air running through it.
Gents, below is a link to You Tube with three videos. Unfortunately there was a generator running near by covering some of the car’s noises. Thanks.
Could you please link to the video itself?
the fastest cars are B8.5 facelifts. Jones, Auditude.
Nobody can see your videos. You posted a universal link that takes a logged in user to their own videos.
trap speed is a reflection of the power youre making. It’s tough to get faster in that short distance (1320 feet) without adding power. So we can see that power = MPH. Stock B8 S4s trap 106-108. Add about 20 hp and you’re adding about 2 mph trap speed. Add 75 hp and you’re adding about 7 MPH. Add 100 and it’s around 10. Simple enough. So adding 100 hp vs. stock should mean trapping in the 116-118 range. Is adding 100 hp possible? Well we know that the b8 dynos around 275-300 whp when stock…and around 375-400 whp when maxed out. That’s worthy of 10 MPH of trap speed. SO what happens when maxed out 3.0T S4s run the 1/4 mile?
When you’re running race gas, a pulley, lw wheels, lw rotors, cooling…you should basically be pushing the TVSr1320 to its max. Remember above I said that means around 500 hp on a B8 3.0T? That’s an estimation. That’s around 400 whp. Maybe a hair more. 400 whp cars at this weight with reasonable gearing tend to trap in the high teens.
APR Put a 1320 on a B7 RS4 and trapped in the 116-118 range with the blower maxed out on pump gas.
APR put a 1320 on a B8 S5 4.2 and trapped in the 116-117 range with the blower maxed out on pump gas.
Audi put a 1320 on the B8 S4 and trapped in 116-119 with teh blower and mod list maxed out on race gas.
Makes sense right? The V8 guys on pump are able to match the 3.0T V6 guys on race thanks to displacement. But the simple fact is the blower is capable of 116-119 on a B8 S4 on race gas with the right parts and a working tune with full boost. Interestingly the B8 S4 DSG guys get an extra 2 tenths vs. a similar trapping manual B8 S4 or a similar trapping manual RS4 or S5. That DSG is fucking magic!
So anyone spinning that blower up to 18000 RPM (blower speed) is shoving abotu 750-800 CFM through and that’s going to be enough to generate around 500 hp net of parasitic losses.
REVO is losing power up top. Primetime points to the boost bypass theory and that makes a boatload of sense. I bet if we do the math, running 18 psi of boost vs. 15 psi of boost = about 30-40 whp. We also know that = about 3-4 MPH of trap speed…and that explains why you’re trapping around 113.5 instead of 117.5 like the fastest guys. Your car is giving up top end.
Now it’s not because of revs. Now it’s because REVO is giving up the boost that your pulley is trying to let the car spin the blower to make.
as for MPH (trap speed) vs ET, theyre closely related and when things are going well and the car is comfortable, they move together also about 1 for 1, per 10 hp. 10 tenths = 100 hp. Thereabouts. Stock record B8 S4 = 12.6. Modded record = 11.5. 11 tenths. We’re pretty much bang on here.
You’re runnign 11.98 vs. the fastest guys running 11.58-11.68. You’re down about 3-4 tenths. Remember earlier I said you’re down about 3-4 MPH? So again, down about 30-40 hp.
It all adds up. Is it the boost thing? Lets have a look at a fresh log, and lets also ask REVO why the car is asking for boatlloads of timing but dumping boost. Let’s ask them why not calm the ignition timing BTDC request down a little and allow the car to make full boost…it needs CFM for top end, not ignition timing.
^^ That’s an incredibly helpful summary/analysis - one that Skywagon should read a few times. He certainly can’t say people on here haven’t tried to help him.
Skypilot is on a fixed income.
I merged Sky’s “Timeslip” thread into this one, given that this is the original thread, and there is no need for two separate threads on the exact same subject.
Jones and Ron both have B8’s. I think it’s been proven both can be as fast as each other with the right mods, conditions, drivers, etc.
Saki gave a pretty detailed reply. My only contribution will be my understanding is the ET will be a function of your power AND your launch AND your tires connecting. The trap is purely a function of HP, so even with a bad launch, your trap will indicate exactly how much HP you’re making.
In summary, [low ET => higher trap] is true based on physics, but [high ET => low trap] is a FALSE logical statement.
The point is this:
While diagnosing your issues with respect to the tune, it’s best to focus on trap, since this tells you how the tune is running and how much HP you are making throughout the entire run.
Once you get the car sorted (i.e. start trapping near the top of the list), only THEN can you start to think about setting record times in ET.
I know you are most interested in being “fast”, which is commonly discussed with respect to ET, but in this case, I think you’re best trying to make conclusions based on trap. ET is more common with all the big RWD HP guys because it takes so much skill to execute the launch. In our case, the DSG makes it so even a caveman can do it, so this is really an exercise in benchmarking the car, not your driving (modulo all the lifting and manually shifting lol). This is just my opinion and maybe someone else can correct me.
My apologies. My tech son wrestled with my computer for an hour to get those in. I’ll try again. Thanks.