Round type and square type inlet manifolds

[DavidLaver]

Am alternative to a rolling road is road testing with an exhaust gas analyser.  I've also heard that exhaust gas temperature is enough information on its own but requires a manifold with tappings up close to the head.   That reminds me - I've got the article "Aprilia Bananas" here from Norman Wilson - who would like a scan...?

Anyone out there "in the trade" know what exhaust gas analyser or temperature instruments are suitable and how to interpret (and act on) the readings?  If not I'll be catching up with someone mid May who does instrumented on-road testing and can report back after.  He takes a scraper on his test drives to fine tune SU needle profiles, he rubs a bit off the side as it doesn't have to be symetrical then measures it up after.

Otherwise its soot colour and plug readings...  Graham Bell's Four Stroke Performance Tuning is my favorite, the Vizard A-Series tuning bible is a good general book for all its title and focus is the A-series engine.

http://www.amazon.co.uk/Four-stroke-Performance-Tuning-Practical-Guide/dp/1844253147/ref=sr_1_1?ie=UTF8&s=books&qid=1208296535&sr=8-1

http://www.amazon.co.uk/Tuning-Engine-Definitive-Performance-Economy/dp/1859606202/ref=sr_1_1?ie=UTF8&s=books&qid=1208296659&sr=8-1

David

[DavidLaver]

This is a nice intro:-

http://www.airfuelmeter.com/english/lsu4_en_sensor.htm

Here's two examples of the sort of gear for on road testing...  I think BWE used to have a very early version of this stuff with the electronics is a suitcase size thingy.

http://www.turbobits.co.uk/acatalog/Innovate_LM-1_wideband_air_fuel_ratio_gauge.html

http://www.aempower.com/ViewCategory.aspx?CategoryID=67

http://trigger-wheels.com/store/index1.html

http://www.innovatemotorsports.com/products/lm1.php

To me its like doing your own welding - once you've got the gear you can spend what would be a commercially insane amount of time fiddling about to get it how YOU want.   I'd love to have one...

David

[DavidLaver]

This is nice - very compact, will interface to a laptop, and got the exhaust gas temp as well.  To improve on this would take a "proper" logger with water temp and throttle posn etc or a "proper" garage "six gas" jobbie.

http://www.driftworks.com/catalog/products/vems-wideband-o2-monitor-with-optional-egt-sensor.html

Perhaps the one downside is needing to put the tappings into the exhaust system.   Yet to find the "lance up the tail pipe" system.   I'll give up soon and "phone a friend" for the answer!!

David

[ColinMarr]

With regard to the photo of the twin-carb set up. I am really sorry to say it’s not mine and sadly, neither is the car that it came from! It’s a photo I took ten days ago of some parts that belong to a friend who is not a LMC member (nor a member of any other club, come to that!) and I am not free to say who he is.

But it is Nardi and probably the same as fitted to the car on the US website that David referred to. The black-crackle finish looks original.

In response to Scarpias’s question, I think the exhaust provision for the standard Aprilia must have been generous, so that improvements to the inlet could yield benefits to power output. And I guess this Nardi set up would have paid off without any other mods. I ran my car with a standard exhaust manifold and the power increments by upping from small-Zenith to big-Zenith to bid-Weber were evident. Yes, I would love to do it all again.

Colin

[DavidLaver]

Saw the guy over the weekend at VSCC Wiscombe - breaking the class record as it happens. 

He uses AEM with bosch sensors.   The sensors are VERY fragile, do not drop even from an inch.  The exhaust lance is something he made up himself.  All his regulars have got a boss welded somewhere into the exhaust system.  It doesn't need to be close to the manifold - a foot in from the tail pipe is fine.   The response even with a sensor way back there is fine.

http://www.aem-power.co.uk/aem_uego.htm

He's considered adding an exhaust gas sensor and a knock sensor but is getting the job done just on air-fuel.  He sees no value in data logging - he tests, adjusts, tests, adjusts etc.  A customer of his was there and said it was a night and day improvement having been setup correctly - ticks over sweetly, very happy on a light throttle, and lots of torque right through the range.   I can remember our MG Midget when we first got it - it felt like a racing car all top end and coughs and splutters and pops but only made 75bhp.  For being set up correctly it ticks over so slow I think its about to stall, drives like a normal car, and makes 75bhp.

David

[DavidLaver]

His other advice was to get a new setup looked at before driving it - he's seen plenty of engines damaged by bore wash with the mixture set up very rich for power and to be on the safe side.  Its not just lean mixtures that do damage.

Looking at the drift-works unit again it has an input for RPM and also for a throttle position sensor.

David