Expected Power Results

[tbloke99]

Taking my 2001 4.5 for a rolling road power run on monday. What precautions should I take beforehand, if any?
What realistic power/torque can I expect. It has just had a new clutch (1000 miles ago), no mods except decatted.

[grey42cerbie]

Taking my 2001 4.5 for a rolling road power run on monday. What precautions should I take beforehand, if any?
What realistic power/torque can I expect. It has just had a new clutch (1000 miles ago), no mods except decatted.

Sensible precautions should include checking tyre wear and pressure (slightler higher is better). Check your oil level and watch the pressure. Try to keep an ear out for pinking or any other strange engine noise. Plus either strap it down or sit on the boot lip. To be honest there no too much you should worry about it's high load but only for a short time. Fingers crossed for that 400+ bhp figure.

Cheers, Steve
Grey 4.2 Cerbie

P.S. Please let us know the results good or bad.

[joospeed]

what steve said .. but also choose your operator carefully, if they don't have an airconditioned booth running very low ambient temp with at least 4 changes of air a minute you'll lose power. Nobles tht I use run at 2degC and even then cerbie temps were often 10 deg higher at the end of the run than the start. i now cnnect the fans to another battery and run them constanty to eliminate the power loss from the ecu retarding the ignition timing. ask what standard the figures are corrected to, this can make 5-8 bhp difference on this sort of output.

[dannylt]

You should expect 330 to 350bhp, and around 300 to 310lbft torque. There have been a few with less power (312!) but no unmodified 4.5's making more. Decat will make no different compared to any of the other random factors.

As for the high load, if the ventilation and cooling is ok, there's no difference in a full power rolling road run and having a flat out 4th gear run on the road.

danny

[ceejay]

Joolz put my un-modified 4.5 on the John Noble RR a couple of weeks ago. The car made 361BHP @ 5805 r.p.m. and 343lb/ft of torque @ 4542 r.p.m. Car is de-catted with sports exhaust and middle silencers (thanks to Joolz for fanatastic sound without annoying neighbours too much) but this shouldn't make any difference to the figures.

We had two big dips in the power and torque curves though. Joolz is looking into ways of fixing this with a re-mapped ECU. Hopefully we can make more power and lose the dips.

Hey Joolz hows it goin?

[dannylt]

Nice one! Are you serious about peak power being at 5800rpm? That seems amazingly low down the curve.

[joospeed]

i think this was the car we ran twice cos we couldn't believe the figures .. came out to within 2 bhp both times I think so yeah it's right. Best std cerbie yet .. sorry danny and richard (previous record holders)

[ceejay]

Danny,

Yup the peak power came in at a a lowly 5.8K. The main concern is the dip in power and perhaps more importantly torque curve @ about 2.5K. The power graph revealed exactly what I thought when driving the car on the road (flat spot at lower rpm on acceleration. Just keep it above 3.5K when giving it some now ........fantastic!!!

www.achieve-stylish-living.co.uk/images/cerb-dyno1.jpg

[dannylt]

Ha! Who cares about standard when you can have 400+? :-) Very interesting though, retarded cams or something? Sounds special though - Joolz you should strip it down and find out why, ideally without remembering how to put it back together!

danny