468 replies to this topic

[Captain Vimes]

It was positively damp yesterday so you're probably right. Started spitting with rain at one point. Wheel Spin at 50mph makes an interesting power run. In perfect conditions Max power is still under 260 so I'm pretty relaxed.

[smiley]

Germans had a theory on roughly 3% loss on every 10 degree airtemp increase.

 

Edited by smiley, 04 March 2016 - 12:36 PM.

[fezzasus]

Germans had a theory on 3% loss on every 10 degree airtemp increase.

 

 

Sounds like that's based on air density rather than thermal saturation of the inlet

[CHILL Gone DUTCH]

Germans had a theory on roughly 3% loss on every 10 degree airtemp increase.  

IAT Or ambient temps outside

[Captain Vimes]

60hp loss is huge. Have you considered removing the tmap and living in ignorance?
You could try it and monitor knock?


I did a few extra runs yesterday to see if the initial results were repeatable. I didn't manage to keep on the throttle above 6.6k without hitting the limiter but is confirmed that the 'hit limiter' measurement is just wrong over 6k.

Edited by Captain Vimes, 04 March 2016 - 12:46 PM.

[smiley]

 

Germans had a theory on 3% loss on every 10 degree airtemp increase.

 

 

Sounds like that's based on air density rather than thermal saturation of the inlet

 

 

yes.

 

[color=#0000ff;]Diese Korrekturformel der Ansaugluft habe ich gefunden.

Diese Formel dient zur DIN70020-Korrektur einer Leistungsmessung auf Rollenprüfständen nach
Umgebungstemperatur und Luftdruck. Hat also mit eurem Problem hier eher nichts zu tun.


Eher doch....Luft dehnt sich pro Grad Kelvin um 1/273tel aus...also hat die Luft bei 273 Grad
nur noch das halbe Gewicht bei gleichem Volumen = halbe Füllung oder halbe Leistung....

Grob gerechnet kommt das mit 3% Verlust bei 10 Grad Erhöhung hin.[/color]

Edited by smiley, 04 March 2016 - 12:52 PM.

[CHILL Gone DUTCH]

possibly the dip the ive always seen in my runs 

as much as ive thought about removing the Tmap i actually think its down to the charged air temp why the power is down rather than the ECU retarding the ignition well that is until the inlet air temps start to change the AFR

[CHILL Gone DUTCH]

 

 

Germans had a theory on 3% loss on every 10 degree airtemp increase.

 

 

Sounds like that's based on air density rather than thermal saturation of the inlet

 

 

yes.

 

[color=#0000ff;]Diese Korrekturformel der Ansaugluft habe ich gefunden.

Diese Formel dient zur DIN70020-Korrektur einer Leistungsmessung auf Rollenprüfständen nach
Umgebungstemperatur und Luftdruck. Hat also mit eurem Problem hier eher nichts zu tun.


Eher doch....Luft dehnt sich pro Grad Kelvin um 1/273tel aus...also hat die Luft bei 273 Grad
nur noch das halbe Gewicht bei gleichem Volumen = halbe Füllung oder halbe Leistung....

Grob gerechnet kommt das mit 3% Verlust bei 10 Grad Erhöhung hin.[/color]

 

 

Translated

 

 

[color=rgb(33,33,33);font-family:arial, sans-serif;font-size:16px;]This correction formula of the intake I found. This formula is used to DIN 70020 - correction of a power measurement on a chassis dynamometer according Ambient temperature and air pressure. Has thus rather nothing to do with your problem. Rather it .... air expands per degree Kelvin at 1 / 273tel from ... so the air has at 273 degrees only half the weight of the same volume = half filling or half power .... Roughly calculated comes with 3% loss back at 10 degrees elevation .[/color]

Edited by CHILL Gone DUTCH, 04 March 2016 - 12:57 PM.

[oakmere]

I think I will be doing my power runs now trying to avoid the limiter as I have also noticed a similar effect of inconsistent readings in the last 500 - 1000 rpm at times.

[Captain Vimes]

So as per the thread in the track day forum, I got it back on track on Monday at Bedford and I'm very happy with how it's all working now.

 

The main change from the last track day was the suspension.

 

Problem:

After fitting the front 1" ARB it improved the tyre wear on track by limiting body roll but it moved the balance towards understeer which made it less balanced at the limit.

 

Solution:

The simple solution was to increase rear spring rates to match the (effective) increase in roll stiffness at the front. So I changed rear springs from 450lb to 525lb. The fronts are still at 350lb but the ARB supplements this in the corners so a difference of 175lb front to rear isn't as severe as it sounds (maybe).

 

I also dropped the front ride height to the minimum it would go while retaining preload. This meant about 5mm less preload at the spring but no idea what this means in ride height as I don't have a level floor to check.

 

Result:

It's now fairly well balanced and still works well on the road. I didn't even adjust the dampers at Bedford.. rears were 25 from hard, fronts are whatever they were last time I moved them..

 

Proof:

 

A sensible quick lap from Bedford. Nice balance and I wasn't passed all day (although there weren't many cars on track):

 

And enjoying the balanced handling (WARNING - same video as in track day thread..)

 

Driver needs some help though:

new video.. 

 

Next mods....? - I boiled the brake fluid so that needs attention - some ducts would be good. - Bump steer and some more front camber would be good too.

 

Apart from that I'm hoping to drive it this year. At some point I'll get some proper track dampers, some sticky tyres and some harnesses but they can wait.

 

[Captain Vimes]

Mot passed today for another year

While I'm updating the thread here's some pictures from Bedford that I bought from the photographer:





And one of my own..

[Captain Vimes]

As ever, there's still a list of jobs to do.. - fit harnesses - fit new front brake pads (again) - fit Ducatisenna brake coolers (see above) - fit rack raiser plates - programme spare key - get the hardtop off and in the loft - try and stop the windows rattling (again) All straight forward stuff so hopefully won't take more than a few evenings in the week.

[Captain Vimes]

After the success of an MOT pass I was somewhat disappointed to come out this morning to see what looked like brake fluid puddled under the rear wheel.

Further inspection left me somewhat confused as I was presented with this:

[Tony H]

Did the damper p*ss itself?

[Captain Vimes]

Nope, but that's what I thought it was...

[Firthy]

Engine mount! Bloody terrible stuff

[CHILL Gone DUTCH]

Coolant from header tank

[Captain Vimes]

It was engine oil...

[Captain Vimes]

From the boot! Some idiot had left a bottle of engine oil in the boot and the lid had come loose and dumped a litre of oil At least it was an easy fix!

[Nev]

From the boot! Some idiot had left a bottle of engine oil in the boot and the lid had come loose and dumped a litre of oil At least it was an easy fix!

 

Ha ha, I once accidentally left a 2 litre bottle of fizzy pop in the boot - the smell and sticky residue that left taught me a lesson too !