Intake Manifold Upgrade

[Purple440]

Hey Guys,

I'm considering replacing my M1 dual plane with a Holley SD or Eddy performer RPM based on recommendations from lots of ppl.  Is there any real gains to be made with an RPM range of 2500-6000?  Or are those for higher duration cams that run 3000-7000 rpm easily?

Personal stories accepted and wanted!

Thanks,

- Doug

[Chryco Psycho]

Either the RPM or SD will be a good upgrade , for second gen Chargers the SD will alllow for better hod clearance& will work in virtually any powerband up to 6500+

[Purple440]

You one of the persons I was referring to but I've also seen that the SD will get me 15 hp on top end, and that's not worth $200.  I'm looking for some proof, like dyno or whatever.  What about mid range?

(get on skype)

- Doug

[firefighter3931]

Both work good and will clear the stock hood with a drop base air cleaner. As for performance the SD will make better top end HP while the RPM will make better tq down low (below 3500) so it really depends on the combination.

We tried both on mine when it was being dynoed.....all the pulls from 3500-6500 rpm (no data below 3500). The RPM was 30 ftlbs better than the SD at 3500 but by 4000 the were even and at peak tq (4400) the SD had pulled ahead. The RPM gave up 25hp at 6100 but it was falling off before that. Manifold selection is one of those things that is combination specific....a solid cammed high rpm build with deep gears and stall will work better with the SD while a milder build with a hydraulic cam with shallow gearing and mild stall will like the RPM dual plane.


Ron

[Purple440]

And compared to a M1 Dual Plane, any opinion on the difference?  My cam is 230@.050, unported 452 heads, valve job and 2.14/1.81 valves.   I'm trying to figure out if it's worth the expense and time. 

Thanks,
- Doug

[firefighter3931]

And compared to a M1 Dual Plane, any opinion on the difference?  My cam is 230@.050, unported 452 heads, valve job and 2.14/1.81 valves.   I'm trying to figure out if it's worth the expense and time. 

Thanks,
- Doug

Doug, with that mild combo there wouldn't be a whole lot of difference between the M1 and Performer RPM....tq would be the same and HP might gain 5-10 or so. Now if the heads were ported and you had a bigger cam...that would be a different story. 



Ron

[Purple440]

That's what I was thinking too.  Thx Ron.