2871R goes rather nicely...

[Rusty]

What belongs to the turbo

[EspenW]

Paul: did you check the gearbox data. Seems weird that the S4 should be geared more than 20% longer than an RS2 (or S6+)?

[Billman]

Because bigger isn't always better with turbo's

The bigger the better is maybe not always true on other things ;-) but in regards of turbo and power and as long the engine can spool it then yes, it is!

[A80Avant]

i have a question i dont understand a bit from the graph(maybe EspenW already noted).

On page 4 of the speed vs time,i can see that on 1st gear you hit 40ish mph,on second you go to almost 80mph and then 3d gear over to 109+mph.

now,if i remember correctly on all runs i have ever done in the rs2,i could never go past 120kms on second gear,which is almost 70ish mph!!!
What kind of gear box are you using on the S4 and also,where is the rev limiter???

[repo]

I think with a 54mm (non Map-Enhancement width) compressor impeller everything above 450 hp is not really possible!

Well, even 71mm r-series compressor flows 50lbs/min. If You cannot do over 450 crank ho with 50 pound flow, You are doing something wrong.

There are 50mm wheels that do more than 50 pounds per minute.

[Rusty]

i have a question i dont understand a bit from the graph(maybe EspenW already noted).

On page 4 of the speed vs time,i can see that on 1st gear you hit 40ish mph,on second you go to almost 80mph and then 3d gear over to 109+mph.

now,if i remember correctly on all runs i have ever done in the rs2,i could never go past 120kms on second gear,which is almost 70ish mph!!!
What kind of gear box are you using on the S4 and also,where is the rev limiter???

There's something wrong with the output. I've coverted the RPM to speed based on my S2 (as I've posted on the previous page) and it looks a lot better. Not sure what's happened there Paul. I'll get some GPS data on the gearing, sensible way to do it would be to set the car at 3krpm in each gear, more fun way is to hit the limiter

[A80Avant]

it would be interesting to do a GPS measurement with the PB or any other meter actually.

[EspenW]

i have a question i dont understand a bit from the graph(maybe EspenW already noted).

On page 4 of the speed vs time,i can see that on 1st gear you hit 40ish mph,on second you go to almost 80mph and then 3d gear over to 109+mph.

now,if i remember correctly on all runs i have ever done in the rs2,i could never go past 120kms on second gear,which is almost 70ish mph!!!
What kind of gear box are you using on the S4 and also,where is the rev limiter???

Yep, I have commented on it earlier. It hits peak power at 5900rpm at almost 99 mph, while RS2/S2 gearing only allows 80mph at 5900rpm in 3rd. Something is off somewhere.

[Rusty]

My power calcs were way out with the data provided. With S2 gearing assumptions it was a lot better.

[A80Avant]

that was excactly what was happening with my g-tech measurements.That rev counter it has is not so accurate as it seems

[S2central.net]

Was just gonna say guys... don't forget the GTech does RPM by acoustic sensing. I did set it up as per instructions, but there must be some error in that... Quite how much I don't know - its pretty accurate on my S2 though.

[A80Avant]

when i tried in mine,it showed that i was revving only up to 5800rpm!! altough it was accurate enough at low revs

[Billman]

Well, even 71mm r-series compressor flows 50lbs/min. If You cannot do over 450 crank ho with 50 pound flow, You are doing something wrong.

There are 50mm wheels that do more than 50 pounds per minute.

Where is this flow and where are these wheels? You can see clearly here that the 54/71mm Garret R wheel doesnt flow more than 45Lbs/m with an efficiency of 60% for a moment!

[Bram]

I look forward to some GT3071R homefries

[Rusty]

Was just gonna say guys... don't forget the GTech does RPM by acoustic sensing. I did set it up as per instructions, but there must be some error in that... Quite how much I don't know - its pretty accurate on my S2 though.

The RPM seems spot on, it's the speed output that's shot.