Cupra R airflow

[Feel]

i used to have a custom map on my lcr which peaked at 210g/s but got 262bhp on dyno. Now have Revo stage 2 and air flow is less but car feels stronger. Havent had it dynoed with revo on it yet. Surely that rule becomes less accurate on mapped cars as some software might rely more on timing than boost values alone?

The way I see it, there's still the same amount of air going in for each cylinder fill (boost dependent, obviously). Advancing the timing just makes the most use of the cylinder charge whilst it's in there - longer burn, more energy extracted. But peak boost/power is peak boost/power, it depends on the shape of the curve as to how the car feels.

Stgae 1 Revo cars "boost like a mofo" low down, but Stage 2 cars make more power...

On my car, within the space of one week g/sec has ranged between 195 and 210, purely depending on the weather, so 210 one day might be 200 the next.

 

[bentaw]

so what we are saying then it is a complete waste of time getting your car rolling roaded cos the figures vary so much you will never know your cars true output, dyno lottery.

There are so many variables that can affect the cars output that £50 seems a waste of money really doesnt it. although i guess they are useful for detecting problems

 

[m0rk]

bingo ben!

Useful to compare known good cars on teh same day on a well run set of rollers

but no use comparing your results to anyone elses on another dyno

 

[Pabs]

so what we are saying then it is a complete waste of time getting your car rolling roaded cos the figures vary so much you will never know your cars true output, dyno lottery.

There are so many variables that can affect the cars output that £50 seems a waste of money really doesnt it. although i guess they are useful for detecting problems

thought u already knew that! - RR's are just a good guideline, u can't cross compare with other rr results from different days/times/locations..


DAMN! Beaten to it by m0rk again!!!

 

[bentaw]

yeah i did sort of but i thought that it was more complex than that, and a bit more accurate than that

 

[Pabs]

yeah i did sort of but i thought that it was more complex than that, and a bit more accurate than that

accurate? Depends on how much you trust the RR and the operators... this is why "dyno lottery is used" - the figures can vary a LOT.. example:

my car got 232bhp last year, that was without FMIC and a few other bits... this year I got 216bhp average. Thats a difference of 16bhp - thats nearly 10% of my cars original power.

I'd hardly be able to say that both my RR results are accurate, and I know which one I believe is closer to the truth. (Its not the one i WANT to believe)

 

[ibizacupra]

want a difference?
in my experience of dyno's (and its been around a lot of em over the years) the same spec motor back then varied from a 250atw figure to a 320atw figure on the same car, same spec, different dyno. and ALL he dyno's say they are the most accurate.

hence my catch phrase "Dyno Lottery" (TM)

70whp different?? sad but true

 

[Pabs]

ouch! that is a HUGE difference!

 

[DPJ]

I'm confused having done some sums here - can someone help? Sorry to quote my example again but I hope you'll see where I'm coming from.

At 193.08 g/s MAF reading, my car was showing 6320 rpm and 1940 mb boost.

At 6320 rpm, a 1781 cc engine (without any boost) would shift 6320 x 1781 = 11,255,920cc of air per minute. That's 11.25592 m3 of air /min. Divide by 60 and you get 0.187598667 m3 of air per sec.

Let's assume the air temperature was 5 degrees. At that temperature, a cubic metre of air weighs 1.269kg. So (0.187598667 x 1.269) it's got 0.238062708 kg of air going through per sec = 238.06 g/s.

Now if I take boost into the equation 238.06 g/s x 1940/1013 gives 455.91 g/s of air going through the MAF tube. So what relationship has this got with 193.08 g/s

 

[bentaw]

i have just put a different MAF on my car and although i didnt get to redline i got to 5560rpm and at that rpm my airflow was 177.14g/s, so does this mean this other MAF is fubard as well, or could it be the code i have the updated code for stage 1 on my car and before i had that put on there i was seeing airflow of 210g/s now i am seeing 179g/s at most

 

[wild willy]

i have just put a different MAF on my car and although i didnt get to redline i got to 5560rpm and at that rpm my airflow was 177.14g/s, so does this mean this other MAF is fubard as well, or could it be the code i have the updated code for stage 1 on my car and before i had that put on there i was seeing airflow of 210g/s now i am seeing 179g/s at most

What was the rpm that you saw 210g/s at as there is more g/sec to be had when you get to 6000 rpm+.

 

[bentaw]

5880rpm back in feb this year

 

[martin CR]

5880rpm back in feb this year

I was seeing only 180g/s on stage 1 also, then went up to 200-210g/s with stage two, then the other mods took it to 220g/s. I think the updated code for the Leon CR flows less, your first code flowed 200g/s and my stage 1 S3 also flowed 200g/s, but the later code seems to only flow around 180g/s.

 

[Feel]

i have just put a different MAF on my car and although i didnt get to redline i got to 5560rpm and at that rpm my airflow was 177.14g/s, so does this mean this other MAF is fubard as well, or could it be the code i have the updated code for stage 1 on my car and before i had that put on there i was seeing airflow of 210g/s now i am seeing 179g/s at most

Did you disconnect the battery for a bit while you fitted the "new" MAF?

 

[Feel]

I was seeing only 180g/s on stage 1 also, then went up to 200-210g/s with stage two, then the other mods took it to 220g/s. I think the updated code for the Leon CR flows less, your first code flowed 200g/s and my stage 1 S3 also flowed 200g/s, but the later code seems to only flow around 180g/s.

What's this updated code? Didn't Revo have a look at Ben's after he had some "funnies" after fitting the FMIC? I thought it was a one-off bit of code rather than an update.

Edit: 180 g/sec with a bogging standard paper filter maybe?

 

[martin CR]

Did you disconnect the battery for a bit while you fitted the "new" MAF?

Why do you have to disconnect the battery?

 

[martin CR]

What's this updated code? Didn't Revo have a look at Ben's after he had some "funnies" after fitting the FMIC? I thought it was a one-off bit of code rather than an update.

Edit: 180 g/sec with a bogging standard paper filter maybe?

The later code is less aggressive

 

[Pabs]

Why do you have to disconnect the battery?

I'd have said that its to let the ECU reset, so its not holding back due to having already learned how the driver drives, and how the car is performing itself...

When you reset the ECU, the car always feels faster for a while - as the ECU learns its boundaries etc. If you don't disconnect the battery, the ECU will still have set these boundaries, and so swapping the MAF out might not make a difference as the car isn't pushing itself enough???


Sorry if the above doesnt make sense - i don't quite know how to explain it...
Feel will though

 

[martin CR]

I'd have said that its to let the ECU reset, so its not holding back due to having already learned how the driver drives, and how the car is performing itself...

When you reset the ECU, the car always feels faster for a while - as the ECU learns its boundaries etc. If you don't disconnect the battery, the ECU will still have set these boundaries, and so swapping the MAF out might not make a difference as the car isn't pushing itself enough???


Sorry if the above doesnt make sense - i don't quite know how to explain it...
Feel will though

I usually reset with Vagcom, if you use the battery disconect route you will have to reset the clock and code the radio.

 

[Feel]

Did you do this on Ben's car then?

I'll give Revo a ring in the morning to find out about this update. I'm fairly sure Kev said it wasn't an update as such, just something they did to try and help Ben out.