Azrael91966669

well look at a super ram huge plenum short runners
whats the point of haveing a wall there if you opened up the runners behind it that wall is just a restriction it may not help much but its not much more work to do and its not gonna hurt

Orr89RocZ

If you look closer, the runners arent opened up much in the middle, beyond the plenum. they come to a point by the bolt holes. You could fabricate it to work, but the way they have it, its more than enough i feel.

Even then the superam still has similar problems of flatlining beyond 5500 rpms

Kevin91Z

I am not sure how much that would help. Its like having a 3 foot long wall in the middle of a 9 foot wide room. You can still travel from one side of the room to the other by walking around the wall. And there is no problem with air being on both sides of the wall. But how much of a problem is having the wall there in the first place?

For those that think we need more camshaft or that 113 LSA is not tight enough, I'm pretty much at my limit with this camshaft. Its 226/232 and I am already not liking it at idle. Just how much difference is 113 vs 112 LSA? I dont think it would be much at all.

Azrael91966669

but i don't believe thats how air flows best . Now if you put an angle on like how the air foil looks on the throttle body it wouldn't matter but if its just flat it will deflect alot of air back , Really I'm not sure how much it would help by removing it but like posted earlier its not gonna hurt .
Air does not like to hit walls i understand your not gonna redo these runners just because of a little air deflection but everything helps when it comes to air flow
ya sure you can walk around it ,
yes the vacuum of the engine will still suck air in but you will get better flow without it there the only reason it is there on a stock Tpi is because the runners are Tubes and there doesn't need to be a gap there i may not have a degree in airflow but come on you have to be able to see that as a blockage

I'm not sure what your overall goal is but if your looking for power past 6000 rpm i don't think tpi no matter what you do is up to it just to long of distance for air to travel smoothly as much as i hate to say it an ugly stealth ram may be better for what your looking for lol.

also why didn't you curve the lower bar that you use to connect the runners air flow is hitting that and deflecting it back not very productive for good air flow example when the wind is blowing stand on the side of house the wind is blowing it blows back at you basic example for air flow flat things do not promote good air flow had you curved it it would be harder to make a good cover to fit yes but would allow the air to separate into the tubes
basically think about running a garden hose into the plenum if you had a clear cover over the runners you would see the water splashing there
what you want is no splashing you want it to run flawlessly out to the intake port
im only offering advice if you dont want it ask me and ill stop posting

pandin

.02 worth

From June 1996 Motorcyclist
Typed by Todd Knighton, Protomotive Engineering

http://g-speed.com/pbh/cylinder-head-tech.html

read the whole article this is just a small quote.

"Ford's 1960's four-cam V-8 also had huge intake ports, and while it turned more revs than the Offy four-banger engines then dominant at Indianapolis, it was no better than a match for them. When given an early peek at the Indy Ford's cylinder-head castings, I expressed the thought that its ports might be too big. Ford's engineers were too polite to tell me how absurd they considered my remark to be, but their expressions made it plain. I was too polite to send them an "I told you so" note after Dan Gurney sent one of the engines to Weslake Engineering in England, where it's intake ports were made smaller and its output got bigger.
Ford's engineers were then vastly ignorant of the world beyond Michigan's borders. They had no idea Harry Weslake and Wally Hassan (who created the very successful Coventry-Climax racing engines) had learned years before not to take too literally what the flow bench said. They were narrowing intake ports to provide nominal gas speeds in the range of 350 to 400 feet-second, making good use of the fact that kinetic energy packing air into the cylinders increases with the square of it's velocity."

1989GTATransAm

Kevin; IMHO you have too much duration on the exhaust for the idle you want. You have a typo as your cam is 226/234 as I have a copy of the cam card. I believe you could use at least 4 degrees less on the exhaust maybe even 6. This would lower the overlap and improve the idle. You have a fine free flowing DynoDon exhaust system so I don't believe you need that much exhaust split. You are around the 75% mark on intake flow/exhaust flow. However you have what you have camwise. Another thing is with to much split for the motor your torque will suffer.


Azrael; You make some valid points. However Kevins intake runners were the first of that style design that were done in pardnership with JerryWho. The succeeding designs made "improvements" to the original design. DynoDon's are a little different than Kevins with some changes. It takes a lot of manhours to modify these SLP runners. I don't know if Kevin will go back in there and do more work.

Then you can take a look at mine. I made some more changes. Some were for manufacturing convience and others for perceived improvements on the airflow. One addressing the situation you are calling out. I used a bullnose or simicircle if you will to split the pair of runners.


Pandin; That is really a very good article. It has a lot of points in there that most would overlook. One is runner taper. I incorporated that into my First Intake manifold project as best I could. The other two are runner length and cross sectional area. The calculations were done for me by computer similation on EA-Pro and also incorporated.

To all: The sorry part about all this is that for all the improvements made they might not really make much of a difference over Kevin's runners. Kevin really made some good dyno numbers the other day. I'm not sure I will do much different with the so called improvements. Maybe not even as good. Maybe we are reaching the limits of the TPI style intake system. The next series of dyno pulls should be very interesting and hopefully tell the tale. However I feel we will have more questions to answer.

Azrael91966669

oh i completely understand they take time to make them not to mention the cost before even being modifiied i figured he whouldnt redo the the bottom half but the top half is just removal of extra material that dosnt need to be there thats the main reason i brought it up if they want to get closer to there goal they need to free up every bit they can
im wondering why the dyno chart is wavy looked like something was messing up unrelated to air flow

for me personaly i wouldnt mind a stock engine to rev past 5000 makeing power really im not an all out power guy i just want extra freeway passing power 4500-5500 mainly thats where the shift is that was the only reason i would want runners like this but im sure they would far out way the cost for the little i want to do

built up engines need more intake then tpi can really give to me a runner mod like that would be great for a stock or minor build but tpi really is restricting the engine no matter what its just got to much distance for the air to travel to get in at any decent speed
i really do love seening you guys test the limits of tpi and then keep pushing them i love tpi but really it was only designed for a much smaller engine thats why its such a restriction on larger engines

Orr89RocZ

Has anyone considered reverse split camshafts?

that way you can run more intake duration and less exhaust to keep idle somewhat happy and yet still make power since the exhaust system is well designed from the head ports to the headers to the piping. and the cam STILL has good overlap for higher rpm scavenging

LS1 guys have seen very good results with their stock heads, but also on modded cars. Just an idea

Dyno Don

Here is the second design:

Attached Images

JMrunners2.JPG (53.9 KB, 222 views)

pandin

On my car 5000 rpm is 77 mph in sec gear and 125 mph in 3rd. what freeway do you drive on?

Orr89RocZ

You have some tall gears my car is more like 6000 in 2nd for 77 and i'm doing near 100 in 3rd at 5000

1989GTATransAm

Thanks Don for the post. The picture clearly shows the difference between the two runner designs. Mine is more like yours. As to which one is best, who knows?

Regarding the reverse spit exhaust. Not sure I would want go that far. Your line of thinking is correct but maybe too much of a good thing. My custom cam came with a single pattern so we shall see what that does on the dyno and my idle.

The overlap on the single pattern at .006" is 8 degrees less than Kevins. He has 58 degrees of overlap and mine is at 50 degrees. It will be interesting to see how that affects the idle. The overlap on my XFI268 cam was 47 degrees. So on my car I will probably have to up the idle to say 800rpm to have the same idle characteristics.

Orr89RocZ

I think we need to get your car on the dyno to see how it works, and make some more assessments on this situation once we get your results

If less overlap doesnt help, then its possible you will need more. OR else more duration to keep the valves open longer at those higher rpms

As far as your idle goes, i dont think it will change much going from 47 to 50 degrees

1989GTATransAm

From my research on the subject of single pattern cams versus dual pattern cams it seems the single pattern cams are a little better on the low and mid rpms and the dual pattern cams are better on the upper end.

Of couse this will vary with the engine combo. If you have a weaker exhuast system then a dual pattern should be better. With the new heads out now like the AFR Eliminators and the Dart Platinums we might very well be throwing horsepower and torque out the exhaust by over scavanging.

Anyways after some research on the subject I decided that Mike Jones my custom cam designer might very well be right on the cam he chose for my car. My intake/exhaust ratio is around 80% and with the excellant free flowing exhaust system from Dyno Don. Based on that I went ahead an ordered the cam.

By the way Ed Iskenderian has some interesting comments on single pattern versus dual pattern camshafts on his website.

Orr89RocZ

i have also seen some things on single pattern cams but most of the impressive motor builds i've seen use a dual pattern. not necessarily a big split but there is a split, reguardless of how well the exhaust flowed or not. LE1-LE3 designs for instance... mild splits for great flowing heads.

There was also a test posted here alittle while ago about single patterns vs dual patterns on some motors and the power generated were close, but i do believe the single patterns gave up torque in some places. I'll have to look for that thread but I'm eagerly awaiting your results

Because my cam has a HUGE duration split and yet i have AFR eliminators with near 75% E/I ratio. we'll see how she runs sometime in April i hope

1989GTATransAm

Bret Bauer is working on an entirely different philosophy. I think he is following the GM ideas that were incorporated into LS-7 motors and some others. They have huge (by our standards) splits on the exhaust versus the intake.

I have not seen anything posted on the theory behind it. Bret is also very secretive about what he does as well as GM. Your camshaft may very well be whats instore for the future. Your motor could be on the leading edge of the new technology.

Orr89RocZ

lets hope so... i hope i didnt dissappoint him by givin the specs out he never said anything about it

pandin

some of the reasons for the split, is to flatten the torque curve and lower the overlap for engine vacuum at Idle. Straight pattern cams tend to have a higher peak and narrower band (good for sticks and drags).

Lets see advance cam timing for low rpm and retarded for high.

do not have any experiance with the rev split.

Azrael91966669

no the issue is driveing 65 car down shifts to 2nd gear right around 4500 and runs up to 5500
this issue isnt the wall people talk about
the issue is it dosnt make decent passing power it just makes less power there

pandin

change to a 3:55 or 3:73 rear gear that will put you into the torque in 3rd instead of past peak hp in 2nd.

Kevin91Z

Here is the next plan of attack. We'll dyno on Saturday the 22nd and see back to back my siamesed runners vs a SuperRam.

Attached Images

	DCP_1109.JPG (279.8 KB, 130 views)
	DCP_1110.JPG (280.9 KB, 112 views)

VincentZ28

I wonder where that Super Ram came from?

1989GTATransAm

The 22nd it is. I might not be able to get there until around noon. I see that Kevin was finally able to get his air intake lid back. I wonder who had it?

Azrael91966669

well the 2nd design of the runners looks much better but still has the wall
my major issue was the wall may let air flow around it but air can not be in there 2 seperat peices of metal there 1 peice plenum one peice runner when you could let air be there increseing plenum size more like a super ram by makeing the full top half the runners into plenum
not that the plenum size is a major issue but really the goal would only be to shorten the runners down but still have the look of TPI
thats what they did with the super ram hugh plenum and shorter runners just not as good a looking package as tpi in my opinon

im wondering what will happen with the super ram on there
in a way id like to see the differance with stock tpi runners and your new runners in a side by side dyno

MikeH