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Location:
Sydney
Registered:
July 2002
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 20V trumpets.
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Tue, 04 February 2003 08:05
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Does anyone know if the trumpets in the 20V's plenum are designed more for noise control?.. or are they to promote the swirling of the intake air?
Also they are not all the same length.. #1 and #4 are the same lengh but are shorter than #2 and #3.
I am debating the pro's and cons of running trumpets and socks as opposed to running the standard plenum with a cold air intake setup with a K&N.
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Location:
Hornsby, Sydney
Registered:
October 2002
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Re: 20V trumpets.
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Tue, 04 February 2003 08:15
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trumphets are designed to bounce the air in pass the valve. (long explination) they will increase torque is simply what they do and should be all the same size.
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Location:
Sydney
Registered:
July 2002
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Re: 20V trumpets.
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Tue, 04 February 2003 08:47
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I assume its some kind of reverberation thing?.. Perhaps i'm going off on a tangent but wouldnt the trumpets then have to be a tuned length for maxiumum effect?.
The guy i spoke to at finer filter seemed to think the weber trumpets they sell should bolt up to the 20v's quads.. i'm taking the plenum to hornsby to confirm this.. perhaps ill have a chat.
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Location:
Sydney, Australia
Registered:
May 2002
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Re: 20V trumpets.
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Wed, 05 February 2003 03:29
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I've got a set of 20V quads sitting at home, and the trumpets are indeed different lengths.. actually I thought they were all different, I'll have to double check when I get home.
What type of 20V have you got AbaddonGZE, AFM or MAP? Are you running the standard computer?
sam.
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Location:
Sydney
Registered:
July 2002
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Re: 20V trumpets.
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Wed, 05 February 2003 05:00
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Silver top.. but running a mtech MT-8
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I supported Toymods
Location:
Sutho/Hills NSW
Registered:
September 2002
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Re: 20V trumpets.
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Wed, 05 February 2003 05:55
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did you notice much difference with the MT8 ??
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Location:
Sydney
Registered:
July 2002
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Re: 20V trumpets.
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Wed, 05 February 2003 06:23
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It hasnt made it into the car as of yet 
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Location:
Montrose, VIC
Registered:
May 2002
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Re: 20V trumpets.
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Wed, 05 February 2003 09:57
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I bought a 20v intake today (throttles, trumpets, plenum), and on pulling it apart, must say I wasn't overly impressed with the quality of construction of the trumpets + plenum. As it wont really fit in my car anyways, I'll be making my own plenum etc. anyways.
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Location:
Hornsby, Sydney
Registered:
October 2002
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Re: 20V trumpets.
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Wed, 05 February 2003 10:22
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Now before i get myself in too deep, i'm not exactly sure about this but i thought i was right. the trumpet should hold the amount of air about to be used for that cylinder for cylce. but if we have two engines with different sized trumpets on different cylinders somethings got to be going on there. talk to some one who knows before taking my advice. i dont want you too fuck something up on my account. but i would assume they would all be the same length.
Can you let me know what you find out if you do come to a conclusion on this?
Cheers Roadrunner
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Location:
Sydney
Registered:
May 2002
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Re: 20V trumpets.
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Wed, 05 February 2003 10:42
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but they may be unequal for the air plenum as the air enters at one end of the plenum..
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Location:
Sydney
Registered:
July 2002
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Re: 20V trumpets.
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Wed, 05 February 2003 10:57
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yeah i thought that too.. they are angled away from teh entering air....
its hard to describe.. ill just grab the digi and show you what i mean..
their is a fair bit of design that went into it.. which is why I am hesitant to replace it with trumpets. see pic
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Location:
Sydney
Registered:
July 2002
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Location:
Sydney
Registered:
May 2002
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Re: 20V trumpets.
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Wed, 05 February 2003 11:07
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how about you turn the lights on 
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Location:
Sydney
Registered:
May 2002
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Re: 20V trumpets.
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Wed, 05 February 2003 11:08
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were them pics taken with a nokia?
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Location:
Sydney
Registered:
July 2002
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Re: 20V trumpets.
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Wed, 05 February 2003 11:39
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lol man i had the lights on.
WITH
the portable light i use for working on the car.
damn old skool mavica just doent liek the dark
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Location:
Sydney
Registered:
May 2002
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Re: 20V trumpets.
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Wed, 05 February 2003 11:46
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looks like the shit nokie phone camera quality pics.
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Toymods Board Member
I supported Toymods
Location:
Turramurra, Sydney.
Registered:
May 2002
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Re: 20V trumpets.
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Wed, 05 February 2003 12:14
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I reckon piss them off. I can't imagine them being better than set of nicely shaped even length trumpets. They've been designed with space as the main influencing factor, it looks like they wanted longish trumpets but just didn't have the room.
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Location:
Sydney, Australia
Registered:
May 2002
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Re: 20V trumpets.
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Wed, 05 February 2003 21:26
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Actually I just took another (good) look at the set that cam with my quads, while they are different shapes, I think they might actually all be the same length. It's a bit deceiving to look at them..
Bigworms right tho. they are pretty crappy looking, you can tell they're meant to sit inside the plenum chamber, they're definately not for show I'll take a pic now and upload it when I get to work.
sam.
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Location:
Sydney, Australia
Registered:
May 2002
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Location:
Montrose, VIC
Registered:
May 2002
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Re: 20V trumpets.
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Fri, 07 February 2003 07:49
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Out of interest, do anyone else's trumpets have numbers written on them? I've seen a few different sets, and every one has had cylinder numbers on the plastic trumpets - was this a factory feature or just that people write on them as they come apart? 
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Location:
Sydney
Registered:
July 2002
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Re: 20V trumpets.
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Fri, 07 February 2003 07:54
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its the order you are meant to throw them away in 
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Location:
1st street on the right
Registered:
November 2002
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Re: 20V trumpets.
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Fri, 07 February 2003 14:34
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Mate has 20v in 2dr 1600s corona, no plenum just 4 x webber trumpets. they do come in different lengths though. But explanations of tuning trumpet lengths would take the rest of my life 
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Location:
Gold Coast
Registered:
October 2002
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Re: 20V trumpets.
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Sat, 08 February 2003 09:45
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| AbaddonGZE wrote on Fri, 07 February 2003 17:54 |
its the order you are meant to throw them away in
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or put them back in 
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Registered:
December 2002
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Re: 20V trumpets.
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Sun, 09 February 2003 03:34
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from what I thought, its that the plenum on the 20v plays a major role in torque, ( i think that was mentioned earlier on)
obviously in a RWD application the plenum becomes useless. I have seen a few ppl block off one end and then cut a hole in the other but once again they still lack a bit of the torque.
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Location:
Phoenix, AZ
Registered:
January 2005
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Re: 20V trumpets.
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Tue, 04 January 2005 00:43
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That's true, a longer intake (valve to trumpet opening) will result in moving the torque a little down the rev range as opposed to shorter intakes that move the power up. I would think for street use one would want a longer intake to push the power down the rev range.
-Sven
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Registered:
May 2002
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Re: 20V trumpets.
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Tue, 04 January 2005 01:23
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But you chaps are speaking of a stock standard motor. If you install an aftermarket exhaust and webbers trumpets you'll be allowing for a healthier breathing motor. Yes, longer trumpets will provide more torque, but will actually restrict your response up top end.
It's all up to your driving style and what your engine setup is or will be.
But i suppose to answer the original question of the reasoning for engineering the trumpets in such a way. Well it's the thousands of dollars Toyota spent to engineer what they had in mind to best suit the market and keep the polution police happy too; i suppose... 
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Location:
nelson, new zealand
Registered:
October 2004
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Re: 20V trumpets.
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Tue, 04 January 2005 02:59
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leave them in. they are there for torque and the last thing you want to do on a 20v is anything that will decrease torque.
if youv got the room and ecu for it then experimenting with different lengths could find some gains but itd take dyno time!
if your engines stock, or near to it then your wasting your time removing them.
they all have numbers on them
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Location:
Gippsland Lakes. Vic.
Registered:
March 2004
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Re: 20V trumpets.
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Wed, 05 January 2005 01:35
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I totally agree with Mr. Revhead on this one.
Pics. of straight trumpets available if anyone intrested. I don't know how to attach them. I checked on F.A.Q. but BROWSE doesn't come up on the bottom of my post page.
Merv. McCallum.
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Location:
Adelaide
Registered:
December 2004
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Location:
S.E suberbs, Vic
Registered:
December 2003
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Re: 20V trumpets.
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Thu, 06 January 2005 11:35
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those standard ones just dont look very good for airflow at all. Toyota may of spent thousands but in the end they wanted something cheap and easy to make with some kind of half decent result. I have a RWD 20V and I am going to fit mandrel bends with some trumpets I am making myself with some exhuast pipe that has been flared out.
Who has experimented with different legths?
How about some non standard ones people have made, pics of them?
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Location:
Gympie Qld
Registered:
December 2004
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Re: 20V trumpets.
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Thu, 06 January 2005 12:33
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Those billet trumpets may look nice but at $185us, no thanks.
I would suggest the Toyota ones are made that way for a very specific purpose, which could simply be to ffit the longest trumpet within the available space. Have a look at the shape it would be far cheaper and easier to make the patterns and moulds and pump out straight ones. They actually have a reasonable curve and inlet shape (considering), better than most cheap ram tubes.
I am going to (attempt to) make up a timber pattern with a very similar shape to the billet ones and use as a mould for fibreglass trumpets. Wil try and fold the edge right back and square about 30mm so there is a nice flat surface to clamp say a set of small K&N style filters instead of the usual socks.
If you are going to make them and you can't a radius like the above aluminium billet ones don't waste your time, you will defeat the purpose. That radius is there to aid air flow. If you have a fairly straight edge on your inlet inlet, even if it is flaired it will be hardly better than no ram tubes at all as it is hard for the air to turn the corner into the mouth of the tube.
Gavin
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Location:
S.E suberbs, Vic
Registered:
December 2003
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Re: 20V trumpets.
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Thu, 06 January 2005 13:01
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if I am not mistaken a pipe which has a full bellmouth has only a 3% higher max flow than one of a 45 degree angled bell on the end of it . I think mine is just fine, I will post a pic when I could be stuffed. I had a friend flare the exhaust sectiona and I ripped into it with a carbide burr, I like the result, as a bonus its stainless, so easy to weld and no rust.
Also my curent engine was running without anything in there, how badly does it effect the power? alot I assume
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Location:
Gympie Qld
Registered:
December 2004
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Re: 20V trumpets.
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Fri, 07 January 2005 08:50
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I am not sure exactly what you mean by your 45% flare, is that just at the tip. There was a tunin ook put out by David Visard for the A Sereis Mini engine that comapred flow restrictions with different inlets on an SU carb. Thsi was off the engine to just compare maximum flow throught carby with different shape entries.
A straight extension of pipe 3" long reduced flow by 6.7%.
A pipe with a 7% taper from end to end reduced it by 5.5%
A 7% taper with a 1/8th radius reduced it by 1.2%
A 7% taper with 1/8th radius but rolled back 270% increased it by 4.4%
With a 1/4 radius and same roll back and taper increased it by 5.2%
The largest increase was by a 3/4 pipe that had an eliptical flare right round. This increased it by 5.8%
A 2" pipe with 10% taper, 1/4 radius and 270% rollback incrreased it by 5.5%.
He goes on to state that anythin with a radius over about 1/8th is going to work reasonably well. If the radius is noty totally formed ie does nto roll back on itself then as long as it turns out at least 60% iit will work.
not sure how that relates to your 45% but I'd like to see the end result.
Gavin
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I supported Toymods
Location:
sydney.au
Registered:
August 2002
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Re: 20V trumpets.
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Fri, 07 January 2005 08:55
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rounded lip velocity stacks (like the t3 ones listed) work the best on a 20v, read mr sherwood site about this kinda shit.
longer is for power?
shorter is for torque?
right? or the other way around?
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Location:
nelson, new zealand
Registered:
October 2004
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Re: 20V trumpets.
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Fri, 07 January 2005 09:09
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longer runners after the t/b is for top end horse power
longer before the t/b is for torque
bit of a generalisation though...
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