Dyno Log..opinions welcomed

B6/7 S4/RS4
#78

First off, don’t feel bad ask questions but make sure to read and try to understand what what others have said. They are trying to help you do what you’re looking to do.

Never apologize, AR is about learning and its hard when you come from sites that don’t want to do anything but hope things work and hold onto data that isn’t good for anything else but bragging rights.

I think part of the issue is, you actually are believing in the TQ and HP readings you’re getting from the Open intake. Both me and Justin just showed you that the TQ and HP numbers don’t add up. It’s a calculation that is getting a bump due to the flare ups that are normal with open intakes.

Again, No, I just showed you that in the world of acceleration when you looked at the 5000 RPM to 8000 RPM even though your open element intake got a huge spike in MAF readings that RPM per second, it was no faster then the stock air box.

I really support you getting your hands dirty and doing your own testing. The biggest issue is, when you did the testing you we not understanding the full results, you need to look much further and when you actually looked further and did the acceleration testing (as that’s what you want to improve) It showed what the real picture was. That picture said, even though the calculation said there is this big hp and tq difference, there was not a measurable difference in acceleration. The reason there was not a difference in actual acceleration was because the hp and tq number isn’t accurate.

The car will feel better with the stock modified air box as you have said. The open element isn’t consistent, you’re getting blasts of hot air and then MAF spikes due to the air not being straightened as its coming into the filter and MAF.

#79

He is referring to RPM per second… IE how quickly your car is accelerating through the rpms.

Using the maf g/sec isn’t always the best way to measure acceleration. The rs246 guys love to but it’s flawed.

One example was a member who tested his car with stock exhaust… And then tested with a 2.75" catless JHM exhaust.

Same road, same spot etc.

The stock exhaust had better maf nunbers by about 10 g/sec, however the jhm exhaust accelerated much faster.

On my own car I found that my JHM exhaust gained me about 20-25 hp (real hp not logging hp) based on how much I accelerated faster (0-60 mph, 60-90, 0-100 etc).

Point is you need to focus on how your car is actually accelerating rather than getting wrapped up in a number from a log parameter.

Another way to look at it is, if I sell a tune and exhaust that makes your car accelerate faster by a full second from 0-100 mph, but your maf and hp logs will look worse… And I sell another tune and exhaust that won’t make your car any faster but your maf and hp logs will look great, which would you purchase?

Easy answer… You’re buying acceleration parts so you want the first one. Focus on acceleration.

#80

Now i completely got what you say.
Whilst i always thought numbers were irrelevant (ie when i flashed the ECU could not think it gave 450hp from 390hp prior but most certainly the difference is big), but “differences” are important. The problem is that i had no idea which variable is the major to look at to get an ideas for it. Now you showed it’s the acceleration rpm/sec.

Now i totally get it…

Thanks a lot guys

#81

reality is, find yourself a standardized acceleration test, and compare your car to stock results

if there’s a quarter mile dragstrip, that would be great because we have a big database of results. If not, a pbox 1/4 mile test would be a good proxy, just have to have the file reviewed for elevation change to ensure it’s a flat area (sometimes flat roads aren’t as they appear)

Or you could race a stock RS4 if you know someone with one. That’s always effective.

#82

What gear should the 003 & 020 logs be recorded in when accelerating.

#83

BUMP… For my question.

#84

3rd gear
flat road
windows closed
A/C off (everything off)
no extra weight in the car
full throttle from 1000-8000

goes to 101 MPH so be careful

#85

sniped…

Don’t go to 8000 rpm in your S4 though.

#86

why the fuck not? more RPM ALWAYS = more power, guaranteed*

*this is not a guarantee

#87

Not in fourth gear I don’t… Our roads aren’t long enough… LOL.

Third Gear, Noted.

#88

I’ll probably settle for 7K… :-\ :-\

#89

3rd 2k to 7k. You don’t have a 8000 rev limit so that would be hard. Make sure the car is warmed up but not heat soaked.

#90

Make note, this is an RS4 thread.

So countvohn, justincredible and jimsgreen - either rev your cars to 8000 or GTFO.

Pussies.

Re: Dyno Log..off topic
#91

I have no choice. You know me I would shit at 9k if I could. I was just helping so Jim didn’t keep trying to get to 8k and wondering why there was this big issue with revving the car past 7k

#92

Cheers Justin - Yep I was aware of my (S4) 7k limiter, I’ve hit it a couple of times… LOL.

#93

Finally got the chance to do two consecutive pulls this afternoon, with slighter colder ambient temps.
2nd pull is better than 1st mostly i guess due to lwoer intake air temp.

https://www.dropbox.com/s/fou0xks4jcvths6/19092014.xlsx?dl=0

But in any case all findings have been confirmed… :slight_smile:

#94

I can’t open the link I’ll have to try later. Did you see a nice improvement with the air box mod? What would you consider your findings.

#95

Looks nice!

#96

Due to better ambient conditions (-2 Celcius vs. the air intake log) the stock airbox supports decrease in air intake temps. The car is less nervous (shown in the low rpm range) and more smooth in its acceleration. It achieves avg rpms/sec vs. air intake:
Stock (25 Celcius) - Air Intake (27 Celcius) - Air intake (28 Calecius)
3k-4k:591 - 610 - 552
4k-5k: 616 - 596 - 540
5k-6k: 574 - 626 - 552
6k-7k: 542 - 533 - 508
7k-8k: 452 - 480 - 400

Obviously there is lot to account for the difference in ambient but the above differencees also stem I think from the airbox.
On a side note, the car’s load is significantly lwoer when operating on teh stock rather than on teh air intake. Please note that logs are performed on the same spot, with teh same direction for comparison reasons.

I will try to re-install the air intake once ambeint drop around 15 so as to check the car’s behaviour.

#97

From the numbers you posted it seems you backed up what CV posted. And from the data you provided it shows a good gain over the aftermarket intake. Sell that and put that money into more mods.