Audi RS2 vs Audi TT

[A80Avant]

I had a go today with a friend of mine who has a stage 3 audi TT quattro.Both cars have been dynoed on the same dyno,mine producing a little something over 334hp now with the latest remap and his producing 346hp both at the wheels.

The result was that he was a couple of cars ahead of me.We started on 2nd gear until 4th gear mids.Im not used to racing so my gear changes were very very safe and slow i must say.This caused a big difference from 2nd to 3d gear which then slowly grew bigger.

After looking at both car's weights,i must say that the rs2 is about 150-170Kgs heavier.(according to carfolio.com).
Can this explain the difference(as well as my childish gear changes??hehe)

[Pirvu Eugen]

Torque....
This is the diference!

[A80Avant]

according to the dyno graphs,he has around 44Kg of torgue for a longer period of time,while i have a max od 52Kg of torgue which gradually dminishes

[Pirvu Eugen]

Big difference.
Anyhow...~420 hp at the engine is nice....this is what i want also....
You have a CAR !!!!

[A80Avant]

hehe! yes it is very nice!

[Keeper of The Kitten]

150-170Kg of weight is at least 10% more mass to move, it will certainly make a difference at all stages, but would normally be more noticeable from the standing start.

[Billman]

what turbo does he had?

[A80Avant]

i dont know excaclty,he told though that it goes up to 450hp more or less.he has ane exhaust cam,stock cylinder head,new rods,and a very very well made software boosting 1.8bar to the red line without overboost and using the N75valve.

[EspenW]

Torque comes into play during the second gear rolling start (depending on what rpm you mashed the throttle at). During 3rd and 4th (if driven correctly) you stay around peak power, and power will determine the outcome.
The TT is more aerodynamic, but it comes down to the higher weight of the RS2.
Go weigh both cars, and you will know for sure what they weigh. Assuming 150kg extra mass on the RS, it will accelerate approx. 10% slower up to approx. 110km/h after that, aerodynamics will become more and more important as power to overcome drag increases by the third power as speed increases. Rotating mass, like wheels come into play too.
BTW, the dyno numbers are from a Rototest hub dyno, right? In what gear were they dynoed?

[A80Avant]

both dynoed in 4th gear on the rototest.
the pull came from around 4000rpm from both of us,and i assume that im lousy on gear changes,as im too slow.most of the distance was made on gear changes

[EspenW]

Interesting. Gear ratios come into play, too. The ratios should be spaced so that you stay as close to peak hp as possible.
The Rototest is a nice piece of machinery, would be fun to take a roll on one.
I have a Mr. Dyno accelerometer that gets the job done, though (generates curves, adjusts for aero drag, temperature, altitude, etc).
I get 260hp in first gear, 335 hp (355hp if uncorrected for air temp) at the wheels in second gear. Higher gear means lower losses to inertia, and the turbo does not have time to spool in the lower gears. Third or fourth gear would yield higher numbers, but the piece of road that I test on has a winter time speed limit of 60km/h... and I use it only for evaluating stuff.
In comparison, the Cooper S of a friend/colleague of mine (he is from Greece too) got approx 135hp at the wheels when stock on my Mr.Dyno (these cars get approx. 163hp on the Rototest. He just got a 17% pulley and brags that he can smoke anyone now.. we'll see (we actually measured a repeatable 5hp increase from an induction kit on the Cooper)

[A80Avant]

gear ratio i dont know,but it seemed that i was changing the gears a lot slower than he was cause as soon as i went WOT the difference at least stayed the same,or got larger but very very slowly.Towards the end of the 4th gear where we stopped,the difference was not gettting any bigger.
On my car i have seen that i get better and longer boost on 4th,5th and 6th gear.He claims that on his car from the 2nd gear he gets 1.6bar of boost and after that he gets 1.9bar up to the red line and holds that on all gears.

[EspenW]

Yep, the acceleration is slower in the higher gears due to gearing and more drag, so the turbo has time to build more boost.
You could have more turbo lag than him, but that is not too likely, as you produce approx the same amount of power, but you have more cylinders and displacement.

BTW, did you receive the KnockSense?

[A80Avant]

yes,will fit it soon!