I am just modifing my exhaust set-up on my car and was wondering which is better for Drag Racing... at the moment I had a crap header with a half lengthed dump pipe under the car..
Now I have a DTR header and was wondering is it better to have a short pipe or a megaphone on the end of it... and how long would you recomend I made the pipe of megaphone??
and do I keep the pipe the same size as the outlet on the header etc etc...
I am running a stock K20A-R... the DTR header has a 2 1/4 or 2 1/2" outlet..

 

for drag, i would recommend the megaphone set up... and as for length, contact Danny about that..
<U>DTRfab</U>

 

A megaphone is going to be better for a drag racing application most times a megaphone will augment the powerband and actully raise it aboce its peak creating a broader more useable range.

As far as megaphone sizing it is going to depends on things such as collector outlet size over all header length, rpm range and other engine parameters.

We perosnally prefer a megaphone that utilizes a reverse cone when properly sized we have seen great results

 

Endyn and Hytech both believe in the meg, there are more pros than cons ... take a look at these testing badboys that Endyn uses ... see what they all have in common

Greg

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CHEETAH &raquo;</TD></TR><TR><TD CLASS="quote">... see what they all have in common </TD></TR></TABLE>

egt bungs ? lol j/k

 

we've had alot of success with hytech headers, usually the header that utilizes big primaries and a long pipe is ment for a huge motor 2.0 and up but if your setup leans toward spinning the motor past 9k i would suggest using a reverse megaphone like the ones burns sell.

 

Good thing burns is on the forum. Now here is what I would suggest. From Burns you can modify your header to have an adjustable Venturi Collector. Meaning you can adapt the different megaphones and venturi sections on your header. I would purchase a few different combinations and dyno them to see what works with your motor the best.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rtype16 &raquo;</TD></TR><TR><TD CLASS="quote">Good thing burns is on the forum. Now here is what I would suggest. From Burns you can modify your header to have an adjustable Venturi Collector. Meaning you can adapt the different megaphones and venturi sections on your header. I would purchase a few different combinations and dyno them to see what works with your motor the best.</TD></TR></TABLE>

In reference to our DYNO-SYS collectors we can also get you a design and work with you on the devlopment process of your header. This way the header can be tailored to your engine program and different track conditions as well!


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Drewh22a &raquo;</TD></TR><TR><TD CLASS="quote">we've had alot of success with hytech headers, usually the header that utilizes big primaries and a long pipe is ment for a huge motor 2.0 and up but if your setup leans toward spinning the motor past 9k i would suggest using a reverse megaphone like the ones burns sell.</TD></TR></TABLE>

Depending on many other things we normally dont prefer a large primary especially coming off the head!

 

What sort of size would be a good starting point for a megaphone??? given that the freight to get one here would almost cost more than the megaphone itself...

any suggestion on dimensions and the exit on the header is a 2 1/2".. so should I start with a megaphone about 400mm long that spans out to 3 1/2" and then have a 50mm reservse cone tapering back to 3"... or am I way off track here???

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dturbocivic &raquo;</TD></TR><TR><TD CLASS="quote">

egt bungs ? lol j/k</TD></TR></TABLE>

o2 sensor bungs

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hondog &raquo;</TD></TR><TR><TD CLASS="quote">What sort of size would be a good starting point for a megaphone??? given that the freight to get one here would almost cost more than the megaphone itself...

any suggestion on dimensions and the exit on the header is a 2 1/2".. so should I start with a megaphone about 400mm long that spans out to 3 1/2" and then have a 50mm reservse cone tapering back to 3"... or am I way off track here???</TD></TR></TABLE>


i would run a burns megaphone part number meg-24715 with a 3.5-4" short reverse cone....

cut back the base of the meg to match up with the 2 1/2 outlet on the header and weld it on...

 

You guys run a 2 1/2 collector? Why use a collector at all? If the header is correct.It shouldn't be much bigger than the primaries.I think only 1 cyl. fires at a time.But I could be wrong.

 

hey Dan, have you guys ever tried either dynoing or running at the track a meg setup vs straight pipe setup ?

we wanted to try that but my welding ability is very limited with s/s. Let me know

thanks
Greg

 

When sized PROPERLY you can see some pretty significant gains

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DTR-FAB &raquo;</TD></TR><TR><TD CLASS="quote">


2 1/2 outlet ...</TD></TR></TABLE>

The actually throat is smaller then that it has a transition that is welded on ... this is a street header we are talking about which has a 2 bolt flange on it.. i could recommend welding the meg on the actual throat itself if you can find someone who can perform a clean cut and weld...

 

Thanks heaps Danny.. I have got a guy making me a couple of megaphones one open and the other with a resersve cone on it, aswell as just a long peice of pipe made up all with a flange on so I can bolt them across and see which works the best.. I will post some results later on next week after I have dyno'd the car.. Thanks to everyone for there advise.. Once I find the optimum I will probably cut the flanges off and weld the megaphone straight to the header...

 

great post

 

What you should do and the best way to hook the meg. to the header is with a marmon clamp and flanges( V-band).That way its easy to change and it won't break off. Also I have dynoed every size tube and meg. you can think of.And......

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RMF &raquo;</TD></TR><TR><TD CLASS="quote"> What you should do and the best way to hook the meg. to the header is with a marmon clamp and flanges( V-band).That way its easy to change and it won't break off. Also I have dynoed every size tube and meg. you can think of.And......</TD></TR></TABLE>

And.....??