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When i got into the c63 i was under the impression the E63 was 400lbs greater in weight than the C63. Some later discussions seem to indicate they are saying it's more on the order of 100lbs more, what is the actual difference in weight?
So I recently picked up 4-1 long tube headers with 3 inch outlet, and I’ll be making a full 3 inch full custom exhaust with valvetronic design universal mufflers….
What gains will I see? lol 😂
When i said "within 10rwhp" of the best of the best, i mean the MBH headers on stock head and cam yields 40-45rwhp... Most brands are getting 30-35rwhp... And less effective designs such as a shorty header etc 20-25rwhp.
There are other brands which are getting similar to the MBH such as IPE and Akrapovic .
The difference being the primary header tube length and diamater. Collector size and design. Your system is a little different than most in that the collector and exhaust system is a full 3", the others are 2.75 or 2.5", so your system may yield some numbers that we don't see very often. I believe your system also had cut outs, so that is going to be an interesting number.
For this size of engine on the 450-650rwhp level we can use Chevy LS data for 6.0 and 6.2L and also Ford 377-408 cubic inch data, the primary sizes that are winning at this power level is 1 7/8" with near equal length into a 3" exhaust system. 1 3/4" kills limitts top end power slightly on this power level and 2" primary is too big in that the low speed and mid range torque suffers. The 1 7/8" has nearly the low end of the 3/4" and most of the top end of the 2". After the collector there is some extension of a few feet or an exhaust system of 3". Richard Holdener showed that some of the headers certainly did require an extension of a few feet after the collectors or you could lose up to 50 ft-lb...
It also seems the most powerful collector is the merge style of collector.
When i said "within 10rwhp" of the best of the best, i mean the MBH headers on stock head and cam yields 40-45rwhp... Most brands are getting 30-35rwhp... And less effective designs such as a shorty header etc 20-25rwhp.
There are other brands which are getting similar to the MBH such as IPE and Akrapovic .
The difference being the primary header tube length and diamater. Collector size and design. Your system is a little different than most in that the collector and exhaust system is a full 3", the others are 2.75 or 2.5", so your system may yield some numbers that we don't see very often. I believe your system also had cut outs, so that is going to be an interesting number.
For this size of engine on the 450-650rwhp level we can use Chevy LS data for 6.0 and 6.2L and also Ford 377-408 cubic inch data, the primary sizes that are winning at this power level is 1 7/8" with near equal length into a 3" exhaust system. 1 3/4" kills limitts top end power slightly on this power level and 2" collector is too big in that the low speed and mid range torque suffers. The 1 7/8" has nearly the low end of the 3/4" and most of the top end of the 2". After the collector there is some extension or an exhaust system of 3". Richard Holdener showed that some of the headers certainly did require an extension of a few feet after the collectors or you could lose up to 50 ft-lb...
It also seems the most powerful collector is the merge style of collector.
Thanks for the info…. Will only know the true number after installing and getting it on a dyno 😊👍
Definately fill us in on the dyno results. I don't know if you mentioned "Row airboxes", if not they are an easy 10rwhp on the dyno and make it sound even more agressive, it's a real gain from what seems to be so simple...
06-21-2023, 05:51 PM
