ram tubes...

[Clinton]

Ok so this has always been abit of a grey area for me.

I've seen a few deifferent styles of ram tubes. long ones, short ones, metal ones, FG ones, ones with filters on them, no filter, big lips on the end of them, std inverted ones etc.



But I dont think I've actually read about advantages of longer ram tubes or FG ones or whatever. Obviously the FG ones would be lighter but is that the only advantage?


The reason for the question is I'm looking to buy some. I'm not too happy with where air is being sucked from with std flipped pieces as it would just be sucking straight of the top of the engine.


So can ANYONE who has ideas on these things PLEASE shed some light?


Thanks in Advance

Clinton

[Beau]

its all depends on the tune and specs of your engine and so on as to what tubes you mate to it. Thats the theory. Im sure some will go into alot more detail.

But to get better airflow you should be running a air box on your 'ram rubes" with a ducting tube to the front of the car for the best cold air induction

[slydar]

the longer they are the more torque you get, too a point obviously. the harder your engine revs, the shorter stacks you need. here it should be noted, on the grand scheme of things, 4ages dont actually rev that hard. so youre really wanting the longest stacks you can physically fit in most cases. 20vs are at an advantage here. ive seen tests done on fairly normal 4 cylinder engines, and basically, the longer the stack, the more power it made, these were ridiculously long, like 200mm or more.

the taper helps the venturi effect as well. so tapering all the way is better than just straight with a bell on the end. ive heard very experienced race engine builders say 7* is a good amount.

a full radius on the bell is better than just a slightly flared end. your engine will be pulling air even from behind the bell, so this helps to get more in, less turbulence around the rounded edge than a sharp one.

the material isnt really important. think of that last. i guess there could be arguments about laminar flow like inside the ports (rough v's smooth) but thats beyond the point of worry about. funny to note black top throttles are a flexible rubber. where as silver top are a rigid plastic. but anyway, dont worry about what theyre made from.

[slydar]

heres some pics

datsun L motor. makes some ridiculous amount of power (well over 200hp)

http://www.ae86drivingclub.com.au/dcimages/1/8/4187.jpg

older FA engine. remember. this 4age runs to over 10,000 rpm. yours will be lucky to see 8000. following convention, if anything, you want longer stacks (if you can fit them)

http://www.ae86drivingclub.com.au/dcimages/1/8/4188.jpg

[ae86hachiroku]

As Slydar mentioned, the air is sucked in from around the trumpet, as opposed to conventional thinking that it goes straight through the middle, so if you intend using a filter, avoid using ones that strap directly ontop of the bell and look for the filters that have a larger space inside, ideally, the ones that do have these space are the filters that fit 2 trumpets per filter.

[ae71neo]

Ive been looking at some longer stacks, but the hardest thing for us is to get around the brake booster and master cylinder. I guess its all good in a US car, but im still trying to find some you can use while retaining the booster.

[ae86hachiroku]

Be a man, say bye bye to the booster... haha

[beagle]

Be a man, say bye bye to the booster... haha

:hehe:

[Rian]

yeh the length will come down to where your want you engine to have its power band...

lower or higher rev ranges.longer or shorter trumpets.

[Vezza]

Ive been looking at some longer stacks, but the hardest thing for us is to get around the brake booster and master cylinder. I guess its all good in a US car, but im still trying to find some you can use while retaining the booster.

You can go the shorter stacks which will fit, other wise the longer Techno Toy ones (70mm I think), will need the rear one trimmed a bit.

Yeah for looks, open stacks look pure horn. Otherwise it's better to run an airbox over them, with a cold air intake as Beau mentioned.

[Sam-Q]

Rian: on a few occasions I have heard reports of 4age engines not responding in a theoretical way to trumpet length changes.

ae71neo: thats easy just have trumpets that curve down thats what I am going to do

[Rian]

sam-q - yeh fair enough, by theoretical do you mean it was tested theoretically.. or it was physically tested and any performaces changes/differences were negligable.... my statement wasnt based on any facts.. just the basic information of intake manifolds for general population... ie the reason for variable intake. ect.

[Sam-Q]

what I am mean is that I have heard a few times now of people fitting trumpets that are longer than what should work and they still gainer power everywhere in the curve. In theory the power should come down in the top end but it hasnt, for these people anyway.

[Vezza]

Interesting, were the car's dynoed or going off feel?

[Sam-Q]

dont know, these peoples reports I have read over the years where vauge to say the least. However one of them was from the result of a dyno on their race engine and they found 300mm trumpets or something stupid like that was the best, I find it hard to remember though