Thread: Interpreting cylinder compression results

Both of works comp cars, and the other staffs own full size comp cars all run Haltech. I'm not into this engine management stuff, but it looks to me to be a pretty comprehensive and user/tuner friendly ECU.

Cool. Well that 4 people recommending Haltech.

LRH, what Haltech unit were you looking to get. On the website there a a few different sorts ranging in price but I have no idea what i should be looking at.

Simon...work comp cars....I thought you worked at a school! I wish i went ot that school.

if you really want to know what is going on in the cylinders, you need a cylinder leak down guage.
With one of these, 100psi is fed into the cylinder through the spark plug hole when it is at TDC compression stroke and a leakage reading recorded in psi which corresponds to a %.
I used to use 5% leakage as the allowable limit in race engines, obviously you can be a little more lenient in a road engine.
The beauty of using this tool is that you can differentiate between ring and valve leakage as you can hear the air escaping either back through the crankcase breather (rings) or up through the induction or exhaust (valves)

I vote for the megasquirt!
I made and fitted one to my previous Rangie. (If I can build it just about anyone can)! Total cost less than $300. Compare that to the Haltech or Wolf.
I removed it when I upgraded and am about to reinstal it on my 93 RR.
This system also has dual fuel and ignition maps so that you can run one set of maps for petrol and one for LPG (like I will) which change's over automatically. I think I might also try to control the LPG via the megasquirt fuel map and an electric solenoid.
Go to http://www.msefi.com/ and be amazed at what is available.

Hmmm. But are you saying the megasquirt is better because it is cheaper or better? I will be trying to get the most out of the engine as well as get it more fuel efficient and I am not to worried about the cost (within reason) but just want good quality, user friendliness and the ability to change lots of parrameters.

Originally Posted by walker

Hmmm. But are you saying the megasquirt is better because it is cheaper or better? I will be trying to get the most out of the engine as well as get it more fuel efficient and I am not to worried about the cost (within reason) but just want good quality, user friendliness and the ability to change lots of parrameters.

I'm a big fan of megasquirt, only because of the price, and I'm a bit of a techno nerd type. I looked into making my own EFI about 15 years ago, but bought a house instead (and then sold my race cars).

Currently going through the megajolt installation for spark control only (Ralf has SUs).

The problem with megasquirt is familiarty.
Not many efi/dyno tuning places have heard of megasquirt and will not have any info or test gear.
However, any tuning place will be able to provide info on adjustments utilising your own laptop with the megasquirt software.