When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I´ve started building a new 'top' to the std manifold.
this is a 'easy' way as a lot of important brackets and more are located in the lower part.
This is an early picture of about 20minutes of testing.
It will probably be this solution but with small changes.
There will be a sheetmetal 'lid' that seals against the bottom, not on picture.
The new runners will raise above that lid and then down through it again into the plenum.
This combined with my bored throttlebody will release some power i hope.
Yes ofcourse. *thumbup*
But i can almost bet one arm that there will only be gains throughout whole register anyway.
Less friction in runners due to round form instead of rectangular with sharp corners.
Tapered runners to gain velocity.
Correct length for a sportier engine.
And, 5.4litre engine can take a loss at ~2000rpm(where the long runners are tuned), if there will be any, the car will be fast anyway.
I do not need the low rpm torque to pull trailers
Awesome. I hope this works out for ya. There were some folks on the c43 forums who polished the intake manifolds and showed that there were gains to be had.
If you're going to redesign the top half, why not just rebuild the whole thing? :x There are intake spacers available that would provide the rough shape of the intake right against the head.
It very easy when you don´t need to build all injectorbungs, throttlebody bracket etc etc etc.
And as a bonus, the 'bottom' of plenum is already done, no need for construction at all at that place.
With all my years of experiance i´ve learned one important thing.
Do NOT try to invent the wheel again!
Things that works with your plan unmodified, leave them.
Not to doubt your abilities, and I do agree on the philosiphy that 10 less lb-ft down low means nothing, but 10 more hp up top means everything(if you bought a performance car and care about the torque curve at 1000rpm's clearly you don't race) but assuming you'll loose nothing seems like an EXTREME stretch.
I'm very interested in your results though. What were stock runner lengths and did you decide what length you'll be going with? I was actually thinking about something last weekend. Something that bugs me, and I guess it's because in the LTx/LSx world I'm coming from half of America owns one then half of them have pulled the motor apart, is 10 years later(15 if you count the 1st, torquey version) there doesn't seem to be a definitive list as to what exactly the restrictions are on the 5.4. A lot of it has to do with A) limited aftermarket and B) pricing. Is the intake so torque biased it's choking up top? There are several cams available, all for stock valvetrain, so are all mods limited until you dive into custom cams/springs($$$) Sure it has twin intake valves, but are the heads a so-so design? Is the casting pretty ugly? Just how much would a hand or CNC job free up, and is it all for not if the intake isn't cleaned up to match the ports? A 5700rpm peak hp isn't bad, but not astounding for an OHC 3-valve.
There's just a lot of questions I'm interested in, even if I would never drop the time/money to do it. I love the research.
He has already ported the heads with good results. He said the casting was not great from the factory.
Exhaust transition from headers to cats is another weak point. Everything is centered around low end torque which is what your average non enthusiast is going to appreciate the most.
wow, looks great. I just started taking apart a spare intake I have sitting at home. But this seems like a much better idea. If you end up selling it I call dibs
did you take into account the added length created by the lower intake portion?
yes, calculated length is from valve to radius on veloctity stack.
my ideas are from that sls manifold acutally, but with small mods to keep everything tight in enginebay
The vacumlines,, i solve that with some bungs welded into the 'lid'.
To make it aviable to trill and tap some connections.
i have been a sucker for acceleration the last weeks, took of my 20" rims and mounted my std 18" rims with Federal 595RS-R tires.
I have now managed 4.6s in 0-60 och 12s dead on 1/4 mile.
With ~116-117mph trapspeed(116.22 according to GPS)
I hope to get it around 118-120mph with new manifold.
Just to break the 12s barrier at the quartermile.
How to get fast 0-60?
stickytires at first!
then a brutal takeoff ofcourse.
How to make that happen with std converter?
Well, you have to be a bit brutal.
push brake as hard as you can.
Then push gaspedal to the limit where it almost breaks loose the rear tires.
Hold a couple of seconds.
repeat three times.
then do an real takeoff.
This isn´t nice to the tranny, but with fresh oil there are no problems.
This way you will actually rise the stallspeed a couple och hundreds rpm.
Makes a huge difference in takeoff.
This is because the oil in tranny gets thinner in viscousity and makes the converter slip a little bit more.
I managed 4.6s on no prepped surface. just ordinary tarmac and about 20degree celsius.
and ofcourse, a little heatup of tires, a small burnout just to rub the tire.
Stop when first little smoke appears, should be just a 0.5-1second long, no more!
This with federal tires, these are a 'semisemi' slick...
06-30-2015, 02:19 PM
