pete mcrash

iTrader: (1)

why wont my car make full boost on the rollers..???....it's been on 3 different rolling roads and it doesn't make the power it has on the road.....spins up slowly and doesn't peak or hold full boost....the car should pull a 30psi spike and then hold 27/28psi.........today it made 27 and then held 23...........why....???............other cars all made boost

pete mcrash

iTrader: (1)

could the airbox not be getting enough air...........the most it's held was 26psi with a cone filter on it

CossieRich

iTrader: (1)

What gear was the run done in Pete?

pa_sjo

One of two reasons is likely.. a) the fan is so shit (typical) that the ACT's were high enough to cause a boost reduction in the ecu.. or b) the rolling road simply didnt load it up enough.

pete mcrash

iTrader: (1)

Rich: today was 3rd...................
pa sjo: but the other cossies made boost, and i run more

rapidcossie

RR isnt capable of putting the correct load on the engine.

AVA's rollers put so much load on the car that mine cant accelerate against it

Christian and Beccy

iTrader: (14)

Not true. It depends on whether the operator knows how to.

It's not good to put too much load on either, in my opinion, AVA's rollers are FAR too hard on the car.

pa_sjo

Christian and Beccy- are you saying you don't use your steady-state chassis dyno to fully load up engines then?

pete mcrash

iTrader: (1)

need to come up there Euan.............the cars getting painted soon the re-mapped.......so i'll be up for a ride up

Christian and Beccy

iTrader: (14)

Pardon?

No, I'm saying that there are ways to load the car up if it isn't making boost.

Also, is the comparison of boost between an in-car gauge and a dyno plot? They may well vary.

pete mcrash

iTrader: (1)

...........but if my guage says 30 psi right or wrong it should still hit that mark.........

Christian and Beccy

iTrader: (14)

As long as you're looking at your gauge both times. (on the road and on the dyno)

You can't compare what your gauge is saying with what the dyno says for boost. Not all MAP sensors are spot-on, thats a fact.

pete mcrash

iTrader: (1)

boost wasn't recorded on the graph............but like said above and as soon as i drove the car home it made full boost on the road..........

rapidcossie

They are the only ones that can create similar loads to a top speed run Christian hence why when I do top speed runs I dont need to watch AFR gauges and listen to det cans cos I know the engine can already take it.

rapidcossie

I have spoken to Alan various times about other peoples problems using different rollers and all he said was that was that if a car was on his rollers it would see boost like it does on the road.

IMO most other power runs are over far too quickly to actually let you see whats happening with a car.

Christian and Beccy

iTrader: (14)

I don't especially watch det or AFR on the runway.