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I just put a GT 350 manifold on my 17 mustang GT. I've been looking at as many GT 350 tunes as I can find.
One thing that I cannot figure out is why do all of these tunes have the IMRC's closed at high RPM in optimal power. Shouldn't they be open? Makes me think the tunes are not stock.
Thanks.
Yeah, the stock GT350 tune I have also shows closed for high rpm optimal power. I changed it to open in my own tune, but I think it probably doesn't matter. The IMRC are opened and closed by manifold vacuum, so my guess is that as you go WOT the vacuum in the intake drops and the IMRC springs open anyway.Quote:
Originally Posted by K44
Also as an fyi, if you get surge with your GT350 manifold, you will need to adjust the Load for Opening and Load for Closing to smooth it all out and eliminate the surging.
I would think that the FRPP3 tune would probably be a good starting point for this kind of swap since you just need those IMRC values as they applied to the same upgrade path, and then you'd be able to see what they did across the board.
I think Plimmer is right about vacuum when it comes to the IMRC being open at WOT. Regardless, my understanding is that the newer IMRCs aren't as restrictive as they used to be, meaning when they're "closed" they're not totally closed like previous systems anyway. FWIW, I have BD, BFE, ER, OS, TP, and OP all set to OPEN at Hi and Lo. I think the only time I've physically locked newer IMRCs is with ported manifolds or when I wanted to eliminate a variable.
For gt350 manifold swap only, you should only need to update manifold volume and it should essentially be drivable correct?
I know I would have to massage the load open/close and can optimize cams later which ford doesn't even touch.
Will I need to do any tq management/tables or throttle body stuff if I run stock throttle and airbox with adapter?
Generally you can just change manifold Volume but also like to change the OP intake valve opening Normalizer it for the higher RPM and Timing.
Gotcha. But should be at least drivable at that point with updating the speed density.
Currently have a power pack 2 and will be adding the 350 manifold.
Will mess with cam timing slowly. For WOT.
Do we adjust the angles separate from the mapped point angles? I think it's like IVO and EVC tables vs rpm?
Anyone also mess with cam angles with the mapped points to try and increase the partial throttle response or felt tq with a manifold swap?
It usually the IVO side that you adjustQuote:
Originally Posted by LightingBlue17
Okay and thank you. Been back and forth a lot. I mean I know there's a WOT tq loss compared to a tuned stock manifold which I'm on the PP2 from ford. So I'm sure I'll feel some loss but still beefier than the feel of my old 3valve mustang.
I always hate the dead feeling once I hit like 6500rpm.
I'm sure if I pull the timing to stock timing and drive for awhile and get used to it the 350 mani would feel normal lol