Rolling road results help?

CupradanM

Guest
Took the leon cupra 180bhp to the rollers today any the results were not quite right.

The car is a standard cupra, made 185 bhp, which means its gain 5bhp from manufacturers spec :lol:

The problem is though the power curve rose and dipped slightly twice before peaking.
It happened on all 6 runs, would this be a problem with the drive to one of the wheels?

Could it just need wheel balancing? Bought a new front tyre the other day and im sure they didnt balance it.

Any help is appreatiated
 
hey mate, lol 5 extra horses? lucky man! is the car completely standard? no induction etc? im sure i read somewhere that the BHP varies slightly from individual car to car, so if thats the case you got a good one!

as to the dip, my mapped LCR has one which is apparently (according to a top mapper that i trust) just overboost and quite normal, but i wouldnt expect that from a standard.

i also at one point had a big dip on RR which turned to be the MAF sensor, so if its a pronounced dip and not just a teenie one id look to that
 

CupradanM

Guest
hey mate, lol 5 extra horses? lucky man! is the car completely standard? no induction etc? im sure i read somewhere that the BHP varies slightly from individual car to car, so if thats the case you got a good one!

as to the dip, my mapped LCR has one which is apparently (according to a top mapper that i trust) just overboost and quite normal, but i wouldnt expect that from a standard.

i also at one point had a big dip on RR which turned to be the MAF sensor, so if its a pronounced dip and not just a teenie one id look to that
Thanks for quick reply and yeh the car is completely standard :p

Its two quite significant dips and a couple people said they saw the wheel kinda jumping up and down. Guy doing the run originally thought it was something to do with the traction control but when it was turned off the problem remained.

I had the tyre changed a couple days before but forgot about balancing the wheels so could this give such a significant dip?

Maybe something to do with the ball joint of driveshaft?
 

munkyboy

Active Member
Jul 24, 2008
106
0
Cardiff
I had mine rolling roaded the other week and it was pushing 193bhp. Ive got a full custom exhaust on forge 007p dv and a cold air intake. My power curve was fine and the guy said that the extra bits and bobs onm my car would have helped it run better and as a standard map was apparently very good.

Maybe a better filter and cleaner air may help it.
 
Thanks for quick reply and yeh the car is completely standard :p

Its two quite significant dips and a couple people said they saw the wheel kinda jumping up and down. Guy doing the run originally thought it was something to do with the traction control but when it was turned off the problem remained.

I had the tyre changed a couple days before but forgot about balancing the wheels so could this give such a significant dip?

Maybe something to do with the ball joint of driveshaft?
a loss of traction would defo give you a dip (or spike on a digital dyno), could be caused by various things, on my last rr star performance thought my clutch was slipping, but it turned out they were spraying the cooling water onto the front d side wheel by accident :clap:

i dont think wheel balance would cause it though, easy to tell if the wheel balance is way out just gradually acclerate up to motorway speed in a staight line and feel for the steering wheel wiggling, if you get wiggle the balance is out, but im not sure that would cause it to slip, easy way to find out is have them checked/balanced and rr it again.

what i would do first though is find a big empty road, drive with the car in 3rd at 1500 rpm, turn the tc off and floor it up to max revs, see if you can feel any dips, i can feel mine at exactelly the revs indicated on my dyno.

if the road is dry and your tyres are warm you shouldnt lose traction, and you will be able to feel the difference between a power dip/traction loss anyway (traction the revs will shoot up/steering go light).

if its traction have a garage check out the drive shaft and all that general area (this is done during MOT if thats anytime soon/recent)

if its power then you need to find out why, did the garage you went to check the ecu for fault codes? if not get it read, if anyone on the forum near you has a vagcom they will prob do it for you if you ask nice/beer tokens.

it still sounds a lot like what happened when my MAF went, but this should show up as a fault code anyway so if you find out its a defo power dip, then a reading is probably a sensible next step
 

CupradanM

Guest
The cars booked in for a full service on monday so it will be plugged into a VAG COM then so this should tell me if there are any fault codes being thrown up. If this all comes clear ill ask the guy to check the front suspension system and see if anything is suspect :shrug:

Thanks for help mate ill try driving up the rev range later and see if i can feel anything. Hopefully after all this the problem will be found :)