At this point if I was buying today, it would be Dana. BUT this thread was asking about headers (not my thread though). Anyway, wouldn't it be great if we could see a comparison between all 496 headers - Stellings, Lightning, CMI, Bassett (any I forgot).
CMI's are around $4500 per set and I believe the Stellings to be similar. Not enough bang for the buck IMO. Lightning can be had for $2000 (mild steel) or $3500 for all stainless polished. Getting a little more realistic IMO. I wonder about the performance in comparison to the others. Bassett, I really don't know anything about including the price.
Anyone with anything further or corrections?
I'll agree that the fuel pressure increase is changing the curve through out the range. I think that's a given. From my experience it does not change it to any negative affect.
We had 3 full days on the dyno with three different 496 engines, and have installed and ran this exhaust on two different boats. By "ran" I mean we've installed and ran for extended periods of time with Mercury scan tools and portable O2 sensor kits installed.
At no time did we have any reason for concern with the 3 pound increase.
This increase was a neccesity on the late model 496 HO's. Without the change, the engine will run dangerously lean.
I personally think it is great that Dana Marine has done enough research to know that more fuel is necessary.
I would think that their manifold must be doing something to require more fuel. Either they are producing more HP or TQ (or both) somewhere than others, or the others are running lean. I sure wish we had O2 and EGT sensors with a more sophisticated computer....
The dyno sheets I have seen around here from CMI seem to have some funny things going on with pressure and humidity plus I see it states 92 octane. Maybe those were misprints and sensors not hooked up or whatever,but ?????
Dana Marine Products, can you go ahead and post a dyno sheets of stock versus your manifolds for us (any of the engines)? I have seen other posts where you clearly state the increases along with the baselines. I am not doubting your claims.
I will see if I can dig up somemore info on them like dyno sheets.. I will post it if I can Jamie / Lakeside
[QUOTE=Bill 3;2040669]I sure wish we had O2 and EGT sensors with a more sophisticated computer....
Are you sure of that? Get ready for big brother to make it much harder to increase HP....IMO
Last edited by tblrklakemo; 02-27-2007 at 02:54 PM.
I would guess that we could make more efficient power if the computer could have more info on what it going on with the motor. Almost like tuning on a dyno. It could get rid of a lean condition, or bad fuel. I don't know, maybe air flow, temp and knock sensors are enough.
And then if we could tune our own motors with the likes of HP Tuners or EFI-Live to make up for small changes such as exhaust instead of going with an across the board fuel pressure increase.
Ok guys here are the Dyno sheets from my rep @ Dana Marine .. They were on an independent facilities' dyno.. Hopefully it will help some of you.. Jamie / Lakeside
Click the link below..
Dana 496 Dyno sheets / Flyer
Jaime looks good... Tried to call you this evening, give you a call tommorrow..
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