Allright, so a few things delayed me but I finally got it done. I'm somewhat disappointed in my #'s, not due the mani, but something is holding my power back (I'm leaning towards exhaust, and couple timing issues).

Anyways, I ran several runs on the same day to test a few Intake Manifold set ups.
1. Stock port matched Manifold with IAB's
2. Stock Mani with IAB's open
3. Modified Mani with Single IAB Plate bored out (prepared by Blacktrax)
4. Modified Mani with Double IAB Plates bored out (prepared by Blacktrax)

Quick explanation before I post the graphs and pics.
Stock Mani gave me 188 horses with 141 ftlbs of torque
Leaving the plates open gained 1-2 horses up high lost torque down low, as expected
Single plate bored out gained 2-3 horses up high, lost torque down low
Double Plate Mani gained 4-7 horses up high, lost torque down low, but fatter torque up high

The point at which the power for non-IAB set ups goes above Stock set ups is consistently at 4500 rpm. That's why Honda has the IAB's open at that point. However when you have less metal in the way, no IAB's, there are higher gains.

Here's the info, make your own conclusions. These dynos were performed at DNR on a dynojet, not at Blacktrax so they are unbiased.

Tha Manifold


Stock vs. Single Plate (red is stock, green 1 plate)


Stock vs. Double Plate (red is stock, blue 2 plate)


My set up for those interested:
Hondata Stage 4b
Mildy ported head with Flat Valves
JDM Block
Crower Stage 3 cams
AEM V2
64mm Throttle body
MSD SCI
Hondata IM gasket
Greddy Header w/ 2 1/2" collector mod
Catco 2 1/2" High flow cat
Apexi Dunk exhaust
Unorthodox Pulley
No PS or AC


Modified by 2lude4u at 6:15 AM 5/19/2005

 

Good info there! Make sure you put this in the official prelude dynos thread.....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2lude4u &raquo;</TD></TR><TR><TD CLASS="quote">Allright, so a few things delayed me but I finally got it done. I'm somewhat disappointed in my #'s, not due the mani, but something is holding my power back (I'm leaning towards exhaust, and couple timing issues).

Anyways, I ran several runs on the same day to test a few Intake Manifold set ups.
1. Stock port matched Manifold with IAB's
2. Stock Mani with IAB's open
3. Modified Mani with Single IAB Plate bored out (prepared by Blacktrax)
4. Modified Mani with Double IAB Plates bored out (prepared by Blacktrax)

</TD></TR></TABLE>

What do yo mean by Single IAB and Double IAB Plates bored out?

 

The middle plate that is sandwiched between the top and bottom pieces that normally houses the IAB flappers. For the Single set up I had one plate, for the double set up I had two plates sandwiched in there. The plates & the other two pieces have had all the metal in the middle removed so that it's just one big opening, not eight small openings. I don't know why I forgot to take a pic of the plates, but maybe Blacktrax can post some. http://www.blacktrax.net/

 

so by "double-plate bored out mani" you mean you bored out the bottom part of the manifold per the picture above, bored out two of the IAB butterfly plates to match (but with nothing in them), bored out the upper piece to match, and put them all together?

thats very interesting I had always wondered what that would do

 

Yes, Greyout, that's exactly how it was prepared.

It basically results in a loss of torque and power between 3500-4500 rpm, and significant increase at 4500-5500 rpm (must be optimal for the runner lengths, some of my other dynos show more extreme jumps at those rpm's), with a good solid increase in torque and power from 4500 rpm's on up, ie more Area.

 

Very nice! Did you get AFR as well? Do you think you can email me the DRF/WinPEP7 files so I can have a better look at the graphs? -&gt; keith@chillybanana.com.

I have a spare IM I could try this out on.

Keith

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2lude4u &raquo;</TD></TR><TR><TD CLASS="quote">Yes, Greyout, that's exactly how it was prepared.

It basically results in a loss of torque and power between 3500-4500 rpm, and significant increase at 4500-5500 rpm (must be optimal for the runner lengths, some of my other dynos show more extreme jumps at those rpm's), with a good solid increase in torque and power from 4500 rpm's on up, ie more Area.</TD></TR></TABLE>

I wonder if a different sized spacer (say 1.5 IAB plate thickness) would move that spike around.

 

I recently removed the IAB plate all together... I wish you could have done a dyno of that... I'm sure that would help with the low-end torque loss but the smaller plenum volume could effect the top-end... But I'm all about that torque...




Modified by Sam1am26 at 11:40 AM 5/19/2005

 

Thanks for posting your results!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Greyout &raquo;</TD></TR><TR><TD CLASS="quote">

I wonder if a different sized spacer (say 1.5 IAB plate thickness) would move that spike around.</TD></TR></TABLE>

I don't know if the spacer thickness has much affect on the spike. I would say that the runner lengths affect the spike the most. If one was to shorten the runners by removing more material further down it would more than likely move the spike higher up in the rpms.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sam1am26 &raquo;</TD></TR><TR><TD CLASS="quote">I recently removed the IAB plate all together... I wish you could have done a dyno of that... I'm sure that would help with the low-end torque loss but the smaller plenum volume could effect the top-end... But I'm all about that torque...</TD></TR></TABLE>

I should've tried that, but didn't think about it. It might help out with low end torque. The added volume of 2 plates definitely helped the top end, especially above 7000 rpm.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2lude4u &raquo;</TD></TR><TR><TD CLASS="quote">
I don't know if the spacer thickness has much affect on the spike. I would say that the runner lengths affect the spike the most. If one was to shorten the runners by removing more material further down it would more than likely move the spike higher up in the rpms..</TD></TR></TABLE>

wouldn't adding the second IAB plate like you did effectively make the runners longer?

 

also: to increase plenum size and decrease runner length, could you maybe try this:

- port out upper piece completely

- remove middle plate completely

- do what you did in the picture above, but cut the barriers between the runners further down, in a half-moon shape

 

to clarify, I drew this:

the MS paint pic represents the cross section, taken at the yellow lines in the photo.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Greyout &raquo;</TD></TR><TR><TD CLASS="quote">

wouldn't adding the second IAB plate like you did effectively make the runners longer? </TD></TR></TABLE>

That's what we were aiming for in order to improve low end torque. I'm not sure if it was achieved. I need to review the results some more.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Greyout &raquo;</TD></TR><TR><TD CLASS="quote">
- do what you did in the picture above, but cut the barriers between the runners further down, in a half-moon shape</TD></TR></TABLE>

That's what I was suggesting if someone wants to move the torque peak higher up in the rpm's. If only I had a couple more manifolds to fool around with I could run a few more scenarios.

 

Excellent info and thanks for the effort and time showing us the results.
You should make higher peak numbers with your mods, the reason most likely be your header/exhaust. Stage 3 cams really shows the gains with a good header and 2.5inch exhaust.

 

Hey Justin,

Its Natalie, I wanted to say im glad you finally got the dyno done. I wish your numbers would have been a little higher. You didnt really loose tq, you just didnt get the gains you were expecting.


As for your motor being choaked, I dont remember what header and exhaust you have, but i know that my engine was being choaked by my exhaust, so i put the Blacktrax ECS on and gained a very significant amount. A good header will open up the engine more also. I was very surprised at how much a 2.25" --&gt; 2.5" gain I got.

youre welcome for getting the manifold work done for free btw. . How do you like everything btw?


Modified by BlacktraxGirl at 1:50 AM 5/20/2005


Modified by BlacktraxGirl at 2:09 AM 5/20/2005

 

Thanks Natalie,
She was the poor lady that slaved late into the night to get this thing ready for me (then I took over a month after that to actually dyno it, for several reasons).

I'm definitely thinking a better exhaust will help me out. I have a Greddy w/ the 2 1/2" collector mod, 2 1/2" cat, then the Apexi Dunk exhaust which I assume is 60mm = 2.3". I thought it was a decent set up, but the dyno is proving otherwise. I may consider the ECS when I go about fixing my exhaust situation.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2lude4u &raquo;</TD></TR><TR><TD CLASS="quote">That's what we were aiming for in order to improve low end torque. I'm not sure if it was achieved. I need to review the results some more.

That's what I was suggesting if someone wants to move the torque peak higher up in the rpm's. If only I had a couple more manifolds to fool around with I could run a few more scenarios.</TD></TR></TABLE>

Wouldnt longer runners make more peak power rather than low end?

 

theoretically longer runners for low end, shorter for high end

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Eddiebx &raquo;</TD></TR><TR><TD CLASS="quote">theoretically longer runners for low end, shorter for high end</TD></TR></TABLE>

Yup. However, according to his dyno, when he double stacked the plates, he lost low end, and gained more high end.

 

thats because when he added the plates they were fully bored out, effectively adding plenum volume, they are not effecting the runners at all, the only way to do that would be to leave the metal in between each runner in the IAB plates.......

good results from the double plate setup, i would also like to see the runners shortened more, try grinding as much as possible off the im where the iab plate bolts on, and maybe do what greyout said, but i would be cautious with that....you would need to completely grind the barrier away as far as you wanted to go down, i dont think a half moon shape will give what you want...

 

After reviewing the the dynos a little more it looks like having 2 plates vs. 1 plate did help a little bit more with low end torque. It's hard to tell since the guy that did the dynos didn't start recording until 3500 rpm, but right at 3500 rpm most of the 2 plate dynos are getting close to or more torque than stock. Of course there is still that dip between 3500-4500 rpm though.

I would like to try a shorter runner set up, even try a no plate set up. Greyout even offered to supply an Intake Manifold. Problem is my wife will take my life if I spend anymore on this car (Manifold port work and the dyno). If people are willing to put up a little cash I can see what I can put together.

 

Question, how much tuning was required to attain the gains? Can you post the AF graphs from each of the recorded runs?

 

We didn't record the AF with the dynometer since I have a wideband O2 sensor and my Hondata hooked up. I did not tune it while doing all of these base runs for any of the dynos posted. I had my car running intentionally rich around 12:1 at WOT above 5000 rpms before performing these dynos so that if the new mani really increased air intake I wouldn't lean out.

Afterwards we did a little fuel tuning to lean it back out on the high end. My last run of the day had 1hp more than the dyno posted after tuning the fuel (ignition is unchanged)