yeah they do. everytime someone sees mine their mind is blown
B Upper to C lower Adapter Finally
- Thread starter USMC53CHIEF
- Start date
yeah they do. everytime someone sees mine their mind is blown
First, let me congratulate you for actually getting this thing done and in the market. It takes a lot of discipline and tenacity to make something like this actually happen. So many times on the internet you see many great ideas that never actually get finished. I am really impressed. (Unfortunately, I can't use one on my KB equipped car.)
Now on to the plenum volume question. To me, it seems as if the plenum is simply a big supply of metered air in front of the runners. It smooths out the relative vacuum pulses coming from the runners so you don't have a lot of turbulence upstream (such as at the MAF). My theory anyway.
It is a lot like an electrolytic capacitor in an electronics system, smoothing out the signal. So I can't see how it could have any impact, plus or minus on the power. In fact, I never understood why anyone would want to put a spacer on any intake manifold, other than as an adapter plate such as this one.
However, I do know that the Manifold Volume does have some affect on the transient parts of the tune. In fact, one way to try to fix lean tip-in issues is to play with the MV in the tune.
It looks to me that the amount of volume your adapter plate would add to the MV would be negligible on a percentage basis. Have you done any estimates as to what the percentage increase in MV is? This could help tuners to build a better base tune, if it has much of a percentage difference.
Also, if anyone does any before and after data logging, it would be interesting to see if there is any change to the tip-in AFR.
This thread just got me thinking...
Now on to the plenum volume question. To me, it seems as if the plenum is simply a big supply of metered air in front of the runners. It smooths out the relative vacuum pulses coming from the runners so you don't have a lot of turbulence upstream (such as at the MAF). My theory anyway.
It is a lot like an electrolytic capacitor in an electronics system, smoothing out the signal. So I can't see how it could have any impact, plus or minus on the power. In fact, I never understood why anyone would want to put a spacer on any intake manifold, other than as an adapter plate such as this one.
However, I do know that the Manifold Volume does have some affect on the transient parts of the tune. In fact, one way to try to fix lean tip-in issues is to play with the MV in the tune.
It looks to me that the amount of volume your adapter plate would add to the MV would be negligible on a percentage basis. Have you done any estimates as to what the percentage increase in MV is? This could help tuners to build a better base tune, if it has much of a percentage difference.
Also, if anyone does any before and after data logging, it would be interesting to see if there is any change to the tip-in AFR.
This thread just got me thinking...
My brain is bleeding after trying to figure out what your talking about lol.
First off thank you for the kind words, secondly as far as a "before and after" look at data and what not, I do not have anything. I didn't get it tuned before (wasn't really a tune needed) and I still don't have a tune now. I am assuming the numbers from a 99/01 cobra would/could work for a base, along with a stock 98...then bounce the numbers off one of the adapter equipped cars.
First off thank you for the kind words, secondly as far as a "before and after" look at data and what not, I do not have anything. I didn't get it tuned before (wasn't really a tune needed) and I still don't have a tune now. I am assuming the numbers from a 99/01 cobra would/could work for a base, along with a stock 98...then bounce the numbers off one of the adapter equipped cars.
I suspect the amount of manifold volume added by the spacer is negligible given the thinness of your plate compared to the the total volume of the upper and lower manifolds, so I suspect that tuning for the difference will never be required.
But it would be useful if at least one of your customers could datalog a few tip-ins with a wideband before and after the installation of the B head upper to see if tip-in gets richer, leaner or doesn't change.
Again, great job. And no one should be overly worried about having to tune for this mod. I am just curious, and a bit anal...
But it would be useful if at least one of your customers could datalog a few tip-ins with a wideband before and after the installation of the B head upper to see if tip-in gets richer, leaner or doesn't change.
Again, great job. And no one should be overly worried about having to tune for this mod. I am just curious, and a bit anal...
Last edited:
Mark, even though I didn't even get close to final numbers, I can attest that it made zero difference in tip in- under 500 ad counts my car is a snap dragon with tip in. manifold volume is a bandaid fix for tip in anyways, as is playing with displacement in regards to load.
One of the issues is, that most of the customers buy the adapter during a c head swap or before the swap so they dont have to buy the c upper and all the attachments. Most of my customers dont have the c upper to compare any numbers too
Have one going to High Point NC, have one left that hasnt been spoken for
What's the cost on these? I'm a bit lazy to look through 8 pages to find it lol..
Also, this will let C heads match up the my B upper/lower intakes?
Maybe someone else can help with this but can I use the stock coils with C heads still? Also, will I NEED headers to match the new C heads as well?
Also, this will let C heads match up the my B upper/lower intakes?
Maybe someone else can help with this but can I use the stock coils with C heads still? Also, will I NEED headers to match the new C heads as well?
Any 4v header/manifold will fit any 4v head
Cost is $200 shipped
Cost is $200 shipped
Last edited:
all of the adapters are officially spoken for, however if you need one let me know so I can place an order. Those who purchased the last two adapters should expect those to ship Monday or Tuesday as I have already shipped the others
Cool. Does anybody know if one c head lower is better than the other? Cobra vs mach?
They are exactly the same
Looking to help a buddy here, hope it's not a bug to post here. A buddy of mine has a turbo Termi, and at his current power level (mid 700s whp) his tuner is saying the stock C head manifold is starting to limit him. Would this adapter plus a B upper be beneficial to him or would it be so minute that he'd be better off just splurging on a completely new intake? Believe his goal is to crack 8's and call it good.
He's running a 99/01 intake btw
hmm I think this is a question for Todd (NaSvt)
What is your expected turn around time to get another one made? It may make my mind up if its a route I can go or not.
I was there yesterday, he told me two weeks before he can cut the next batch. I already have the hardware, but I would get it on a Friday(16th) evening and ship it Monday morning (19th).
Ordering another batch, any one need one? Have 3 spoken for..... now is the time to order some
Brian, I will be placing my order hopefully Thursday if not Friday.
Users who are viewing this thread
