4.0 intake manifold Log vs Horseshoe style.

John, please have your manifold flowed and share the numbers. I would love to see a '99 intake that has been extrude honed and compare the stock log to stock '99 to extrude honed '99, and your's. A 4 monifold comparison.
 
I hope it will be a success and would be a big bonus if it was a huge success. Theoretically
it should flow like crazy since it's sort of like a velocity stack but it's more like a side swept
twin TB setup, well you'll see. Don't want to give too much away, then there's no suspense lol.
 
John(XJ)Jeep said:
I hope it will be a success and would be a big bonus if it was a huge success. Theoretically
it should flow like crazy since it's sort of like a velocity stack but it's more like a side swept
twin TB setup, well you'll see. Don't want to give too much away, then there's no suspense lol.
Click to expand...

Give us a teaser!!
 
CobraMarty said:
John, please have your manifold flowed and share the numbers. I would love to see a '99 intake that has been extrude honed and compare the stock log to stock '99 to extrude honed '99, and your's. A 4 monifold comparison.
Click to expand...

Extrude hone is a poor idea. It removes as much as .039" of material and doesn't really do anything useful as for as porting is concerned. It will also remove more material on the high velocity spots than on low velocity parts, think in a tight bend.
 
I've read only good things about it. Expensive but good. Equalizes the runner to runner variance as well as increase the flow thru each runner. I think that the material has some weird viscous properties such that the high velocities areas gets little abrasion force. I only wish I had $700-800 to get it done.
 
CobraMarty said:
Equalizes the runner to runner variance
Click to expand...
How? There is no control over direction. Nor is there a flow bench or any kind of flow mapping involved.
 
Well, I for one see zero sense in spending in excess of what, $700, to modify a factory manifold. You could scratch build one for less including flow bench time. Given the port locations of the engine, a twin TB each with it's own plenum would be an acceptable compromise as long as the runners are kept as short as reasonable. The plenums are required for the vacuum ports and I would recommend a cross connect line between the two to help balance the vacuum. Old technology that. Most European vehicles with multiple carbs did this just to help in the balance. If you do not need vacuum ports as you have an electric vacuum pump, the plenums can be deleted.

A flow bench is required as you absolutely can not just shade tree an intake manifold. And, once you deal with the manifold, how are you going to deal with the injector duration variance that exists. It has been discovered (not by me) that the factory does not run all of the injectors at the same pulse width at any given rpm. I suspect it is to "correct" for less air flow on the affected cylinders. So, once you start providing more air to those cylinders, they will go lean (relatively speaking) as the PCM only corrects for gross, overall, AFR.

I still say dumping the entire mess in favour of an AEM EMS is going to be the best way to go for performance as it will accept multiple wideband O2 sensors.
 
LOL Given your comment o-gauge, it just makes me want to do it more now. Thanks for
the reminder on end cylinder situations but that's already been covered not to mention
the cross connect which is actually going to be remote vacuum cross connect there is
not going to be any room for the fittings anyway.

I expected someone to say such things, don't worry though it's not a jab at you I understand
the criticism and most normal people would agree. It just doesn't sit well with me when
someones asks what I did with my Jeep and the story comes out as "I was in the middle of
building a custom intake manifold when someone on the internet said NO just buy this
AEM controller instead of doing that." coming from a guy that is known to fabricate everything
himself, usually for fun.

Don't worry though I'm seriously trying not to put you down or anything just giving you my
point of view, that's all. I'm just throwing everything into the wind including caution simply
because I can.
 
John(XJ)Jeep said:
LOL Given your comment o-gauge, it just makes me want to do it more now. Thanks for
the reminder on end cylinder situations but that's already been covered not to mention
the cross connect which is actually going to be remote vacuum cross connect there is
not going to be any room for the fittings anyway.

I expected someone to say such things, don't worry though it's not a jab at you I understand
the criticism and most normal people would agree. It just doesn't sit well with me when
someones asks what I did with my Jeep and the story comes out as "I was in the middle of
building a custom intake manifold when someone on the internet said NO just buy this
AEM controller instead of doing that." coming from a guy that is known to fabricate everything
himself, usually for fun.

Don't worry though I'm seriously trying not to put you down or anything just giving you my
point of view, that's all. I'm just throwing everything into the wind including caution simply
because I can.
Click to expand...

You misunderstand my post. Not a criticism at all. I will be waiting to see what you come up with. HESCO had, for a time, a dual TB intake manifold and the folks at Clifford had a 6 TB manifold. You can still find photos of both on the net. In terms of total performance, you simply can't beat one barrel per cylinder as a method of control be that a Throttle Body or a Carburetor. The ide is to keep the charge velocity as high as possible to the valve.

I was only making suggestions of things to watch for. Vacuum for the HVAC being one concern and fuel distribution being the other.

BTW, the AEM F/IC can not correct the injector pulse width variance in any way, shape or form as it has only one table to work from, not six. For that level of control, the EMS is needed.

But, back to the post, here is a link to a post by someone who did the retrofit to the new intake and documented it. The fact that it is on a Grand Cherokee is meaningless in this case.
http://mallcrawlin.com/forum/showth...-intake-manifold-swap-with-REAL-DYNO-NUMBERS!

Before you slam the mallcrawl site, read the posting. Good stuff there with photos and real world numbers.
 
o-gauge-steamer said:
I still say dumping the entire mess in favour of an AEM EMS is going to be the best way to go for performance as it will accept multiple wideband O2 sensors.
Click to expand...

I'd advise against that, just look around at all of the issues the Viper guys have had with the Viper EMS, I presume that is what you were going to use since it would be almost plug and play into a jeep? Unless you plan to get a 30-1050/6050 and build your own jumper harness/engine harness but if you did that then you would loose your factory gauges since they are all bused to the cluster via CCD. Your best bet would be to have someone build you a tuned calibration for your stock computer that supports boost and has the accel timers disabled along with baro correction and keep using the EMS that Chrysler spent millions of dollars to develop and test. :wave1:

But hey, what do I know, I'm just the 700 pound gorilla in the room.
 
Is this the type you are trying to build?
AUT_0828.JPG

click_enlarge1.php
click_enlarge1.php
 
See? The manifolds have been done before, for carbs. The Offy appears to have only one port for Vacuum, I would tap all six runners and install an equalizer to get a better vacuum signal for the HVAC.

Thing is guys, almost everything has been either done with a good deal of success or attempted and failed due to the technology not being there at the time. There is a very old saying that states "When it is time to Railroad, tracks will be invented".

I think a multiple TB manifold would be very interesting. I also would not have the TBs pointed down or directly sideways, but would point them, at an angle as directly at the valves as possible. I would aslo use a "master" IAC tied into all of the runners so the PCM does not have to try and control more than one. Which it will not do...

EMS installation. The plan would be to dump the gauge cluster all together as I am not a fan of bodging together systems just to keep factory gauges.

Like I said before, both HESCO and Clifford tried to sell a multi TB manifold and the products died due to a lack of interest.
 
o-gauge-steamer said:
EMS installation. The plan would be to dump the gauge cluster all together as I am not a fan of bodging together systems just to keep factory gauges.
Click to expand...

What are you planning on doing about the CCD messages that are sent to the transmission controller for RPM and Throttle position? Also what do you plan to do about the charging system?

if you REALLY have your heart set on an ems I think you should get a supra twin turbo AEM as that is the only ems AEM ever made that has an automatic transmission controller and figure out some way to setup an external voltage regulator on the alternator.

Having seen first hand the horrors of an AEM on a viper you're going to have a fun time making it work. Also AEM hasn't quite got the code right for controlling the stock stepper motor idle valve and the thing would constantly loose track of where the idle motor was and cause the car to go nuts. This is not a one time occurrence either, I've seen over 30 chrysler cars(vipers, srt4s, dragpak challengers etc) with faulty AEMs were the owner just got fed up and went back to a stock ecu with a tune.

Another major thing to note is AEM does not have very good accel enrichment and you are going to ALWAYS have an off idle hiccup when you blip the throttle, no amount of tuning can fix this because their enrichment is a fixed percentage were as it need to be a curved scale.
 
Nah, don't worry I'm trying not to be hostile and I didn't take it as a %100 criticism I'm just going
to go through with it and see what I get. Like I said I'll make a thread for it so it won't be clogging
up this one. Everyone can make their assumptions there instead of here that's all.

But I'm glad to see some people are interested for the sheer concept of curiosity.
 
Has anyone done a test of the flow characteristics of the log vs the horseshoe intake? Cfm, velocity, etc... The only thing I know is that the horseshoe intake has much less volume than the horseshoe intake.
 
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