Dyno results - what do you think?

[1971rb26dett]

I believe the stock carb bodies flow 130 cfm a piece. So even a 3.1 stroker at 100% VE can still use the stock carb bodies. You would only need to upgrade to SM needles.

[Brett240]

I believe the stock carb bodies flow 130 cfm a piece. So even a 3.1 stroker at 100% VE can still use the stock carb bodies. You would only need to upgrade to SM needles.

my 3 litre made 160hp @ wheels with properly tuned su carbs, not bad.... but custom fuel injection saw it jump to 218hp.

thats a fair difference on what the SU's could achieve compared to fuel injection - at least on my engine anyway....

[Dan Baldwin]

You shoulda tried retarding the ignition timing until it started to lose power. You proved advancing it further hurt, perhaps retarding would've helped. In my limited experience, there's usually a ~5deg range where power is unaffected. I set mine to the lower end of that range (~34deg max advance in my case).

Your peak torque seems very low for 2.8 liters. Should be in the neighborhood of 165 or so IMO. Flat-top pistons would help you out a lot.

As far as cam timing, retarding it (not advancing) is what generally helps top-end at the expense of low-end.

A mild cam and bigger valves would almost certainly extend your torque curve upwards without unduly hurting the low-end.

[SteveK]

280zx Fever

Those results you posted, 500 newton metres of torque equates to in excess of 340 foot pounds -- bloody hell, the BHP seems odd though

[1971rb26dett]

Originally posted by Dan Baldwin

A mild cam and bigger valves would almost certainly extend your torque curve upwards without unduly hurting the low-end.

That hits on something I've been meaning to look into for a while now.

Dan,

Where is it that you get bigger valves for these heads and how much bigger can you actually go?? There really doesnt seem to be much room.

[1971rb26dett]

Originally posted by SteveK

280zx Fever

Those results you posted, 500 newton metres of torque equates to in excess of 340 foot pounds -- bloody hell, the BHP seems odd though

I was trying to make sense of that dyno chart too. There is no way a NA L20 motor makes more than 160 lb/ft of torque. And that is full race built.

It's definitely not forced induction because the MAP is showing -0.4. I am still scratching my head on this one.

Come back and explain this chart to us yanks please