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jimnielsen
18-09-11, 10:16
A beautiful day for car racing today! Just a brief video take from my 155 Q4 a few hours ago..

It was going well - and quick - but then I cracked a disk rotor...


passing rp - YouTube
Steve Webb
18-09-11, 10:26
Looking pretty damn quick now Jim.

What happened to the screen? Has it just cracked due to the hard suspension and too much kerb action?

It sounds like you are getting a bang through the exhaust on lift off as well, is that a side effect of the fuel, and the amount you need to throw in there?
jimnielsen
18-09-11, 10:55
Yes Steve, the screen cracked ages ago - I cant even remember how it happened really! I have lifted the rev limiter higher so that the car does not run into a situation where it has ignition cut - because then it really bangs when the ignition comes back on again! The bangs are not too bad now - I think I may just leave it - Although it is messing with my air fuel ratio sensor..
1NRO
20-09-11, 07:43
It does look quicker Jim, sailing along with ease. Has there been much lost at lower rpm now it has different cams?
jimnielsen
20-09-11, 12:40
No Nik, its faster all over - It wasn't a good day for fast times as a lotus lost 5 liters of oil on the racing line on a few key corners - but I still did my fastest time ever - fastest Alfa by a mile...

I still have underlying boost control issues - but I will live with them for the time being - really the car needs a different inlet plenum, and an exhaust manifold with an external wastegate....

by the way Nik - is there anyway to improve oil pump efficiency. I am getting the oil temp to 110 degrees C and have very little oil pressure at idle - its fine after that.. what about you Steve NZ - any input for this..??
jimnielsen
21-09-11, 09:47
This is a video taken of the same sequence (above) but from the Alfasud racecar that I pass towards the end.. its @ 2:24 into this vid - looks cool to a 155 Q4 passing...


My Movie - YouTube
Steve Webb
21-09-11, 10:00
Is someone on their way back from the builders merchant? I think I saw a pick-up (ute) out there on track !!
Brul(tm)
21-09-11, 10:53
I think I saw a pick-up (ute) out there on track !!

Lol, I was thinking the same thing :lol:

Looking good there on the track Jim :cool:
jimnielsen
21-09-11, 12:33
yep - a 'ute' with 600+ hp...pretty slow in the corners...
Steve Webb
21-09-11, 17:27
...pretty slow in the corners...


http://homebrewandbeer.com/bitsandpieces/images/ute.jpg

Maybe the ice melted and was sloshing about in the back upsetting the balance.
:rofl:
1NRO
21-09-11, 21:43
No Nik, its faster all over - It wasn't a good day for fast times as a lotus lost 5 liters of oil on the racing line on a few key corners - but I still did my fastest time ever - fastest Alfa by a mile...

I still have underlying boost control issues - but I will live with them for the time being - really the car needs a different inlet plenum, and an exhaust manifold with an external wastegate....

by the way Nik - is there anyway to improve oil pump efficiency. I am getting the oil temp to 110 degrees C and have very little oil pressure at idle - its fine after that.. what about you Steve NZ - any input for this..??

Faster all over sounds great, I thought maybe you'd of seen a loss at lower rpm, maybe the higher Cr is masking that trait. Wonder what it'd do with a ported head and manifold :unsure:

Not sure on the oil pump, never messed about with it myself. Shimming the relief valve spring has been touted before as increasing measured pressure but no experience myself, strikes me that's not improving the efficiency though. With the measured pressure being fine under load I'd hazard a guess at the efficiency being fine, possibly the oil is a little hot/thin for idle? Fine when started from cold?

Your using the new ECU to control boost? What's not right about the control?
jimnielsen
21-09-11, 22:44
.. Steve - yes, just like that ute - it probably has beer in the back. The one in the video is a 5.7l chev powered one..

nik..yes, oil pressure is fine at startup - but after 12 fast laps its too thin.. I am using Castrol 10w60 race oil..

like this -

http://www.castrol.com/castrol/productdetailmin.do?categoryId=9006581&contentId=6008856

Oil temp is getting to 110 degrees C.


yes, boost unfortunately still has a 1/3 second ripple of about 0.15 bar..using the built in Autronic ECU boost controller.


jim...
wrinx
22-09-11, 09:14
I think you need to look at improving cooling for the oil, not increasing flow. Doing that won't necessarily allow time for cooling as it speeds around.

wrinx