Quote:
Originally Posted by Irace86.2.0
I was searching, and I couldn't find a single dyno for someone running an Ace 150 or 250, except for RHD cars, which was 250, and it seemed to leave some of the torque dip in place.
I get that removing the torque dip is the utmost concern for NA applications, and low end torque is desirable for many people running superchargers too, especially centrifugal superchargers, but I was surprised to see nothing on the comparison between these difference overpipes. I would assume some people are doing track sessions and would want more power up top.
Does anyone have a dyno graph comparing these different overpipes? I am especially interested in any graphs comparing these overpipes with forced induction. I have a Harrop supercharger, and all I have seen are numbers and dyno graphs from the Ace350 with the Harrop/Edelbrock.
The other thing is that the Ace150 is essentially a slightly longer JDL 4-2-1, but the JDL header seems to fill the torque dips on every dyno I've seen posted, so shouldn't all the overpipes fill the torque dip?
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I don’t think anyone has done direct swap over comparisons. Ace has mentioned the difference and expected benefit/gains. Here are two of there quotes.
“150- highest peak HP and lower torque
150- robotic weld at 2-1 merger
250- 1-2%HP drop from 150 and 3-4% more torque
250- 100% hand welded
350- LHD cars only, 100% hand welded
350 dyno sheet available here:
http://www.ft86club.com/forums/showt...t=80609&page=5”
“ 350= max torque (202.4NM), lowest peak HP (175.1HP)
250= torque (approx 200NM), HP (approx 178)
150= lowest torque (approx 195NM), HP (approx 182)
These numbers are approximated off percentages of the 350 when we did a stock dyno run with OEM frontpipe”
As far as jdl 4-2-1 vs ace 150, they are very different. The CS400/350 are actually the closest in design.
The JDL has much shorter 4-2 runners vs the ace header, and then the JDL 2-1 runners are very long about the same length as the 350/400 ace overpipe
I posted this in another thread
“ Longer front runners 4-1 or 4-2 increase power at the top end
Shorter front runners 4-1 or 4-2 increase power at midrange
Longer 2-1 runners increase mid range,
Shorter 2-1 runners increase top end.”
Obviously with tuning techniques and VVT you can maximize and minimize the pros and cons of these effects to some extent.
Personally I’ve never understood the wanting more mid range torque dip argument, I don’t think power under 5k rpm matter too much. Besides in 1st gear you should never be WOT under 5k rpm. With a 350 header you accelerate from stops/onto freeways with 10% throttle with a 250 you use 15% throttle, don’t see why it matters, but at 5k+ rpm both at 100% WOT thats where max performance matters in my opinion.