I found without the secondaries the 2.5L took a very noticeable hit below 2500rpm. (I.E. tractor range
)
2500-3000rpm was a little weaker but nothing overly noticeable or unliveable.
Above 3000 rpm there was no loss.
Couldn't tell you what it gave on the top end but I would not be surprised if it was 5 FWHP or maybe more from 4000 to redline. (UIM, intake, heads, etc all play a part too)
Heck even if it was miniscule I don't have to worry about the POS IMRC fluttering or it closing every time you leave WOT.
That is all once you have the spark advance tuned in properly (KEY WORDS!!!)
Also you have to realize the my UIM is EH'd to the limit. That itself makes a change in the rpm range of the runners since it's altering their max flow ability and low speed velocity.
I strongly believe that mod alone allows for a much better power curve above 4000rpm. Especially with the larger 3L engine.
Yes the true duals with balance pipe are wonderful for fat midrange TQ and great top end HP but if the engine can't suck the air in to begin with you are not getting full benefit from all of your other mods.
I think I am now finally reaping the full benefits of the EHing. Though my plans were always to build a 3L so all my mods were done with that and other future projects in mind
