6g7x Aftermarket Headers

[Keith6110]

I had taken measurements of my Megan Headers for my 6g72 engine. I had just thought maybe people would be interested to see them.

Individual cylinder exhaust pipe




Before the "Y Pipe"





Output after "Y Pipe"

[boostzealot]

outer diameter isnt what makes a header or any exhaust flow better, remember its the inner diameter. wall thickness and bend radius are the important things for sure. good measurements though. do you mind taking pics of this set of headers like you are critiquing it?

[Keith6110]

yep, I'll put up some pictures later and get some inner pipe measurements.

[SPD_FRK]

Thanks for posting up this stuff man. I (as well of the rest of us now) know for a fact that the Megan headers and the cheap Ebay headers are identical. The main tube diameters are the same. Wth the OD measurement on the mid-pipe section I would assume that section is probably 2.1xx" ID (same as the Ebay). After the "Y" section though may be the only difference between the two, but I will have to get measurements on mine here to see. I "think" the Megan system uses a 2.5"ID though.

[Keith6110]

Thanks for posting up this stuff man. I (as well of the rest of us now) know for a fact that the Megan headers and the cheap Ebay headers are identical. The main tube diameters are the same. Wth the OD measurement on the mid-pipe section I would assume that section is probably 2.1xx" ID (same as the Ebay). After the "Y" section though may be the only difference between the two, but I will have to get measurements on mine here to see. I "think" the Megan system uses a 2.5"ID though.

Ha no problem. Figured it's not helping anyone else that may be curious if we kept it a pm. Let me know if you want me to grab any other measurements before I put it on next weekend.

[SPD_FRK]

Totally agree with you man, this is what I had planned to do with the information anyways

Just get the inside diameter measurements of the primary (which you have done), and ID where the mid pipe connects to the headers. It's hard to tell what the ID would have been on the piping that was originally attatched after the Y pipe though. I know on my set the Y pipe section was wider before entering the flexpipe and then narrowed down to the smaller diameter piping...but I have to double check mine again.

[Keith6110]

alright, I won't be home again until friday. You'll have to wait to see measurements until then

[m-rod]

I wish I would have measured my RPW's before installing them. I believe they are 2.5" I.D. where they would meet up with the cat, but the rest I never checked. It would be an interesting comparison to see really how similar they probably both are to each other.

[Keith6110]

I wish I would have measured my RPW's before installing them. I believe they are 2.5" I.D. where they would meet up with the cat, but the rest I never checked. It would be an interesting comparison to see really how similar they probably both are to each other.

Definitely should have! It would be interesting to see the difference.

[SPD_FRK]

alright, I won't be home again until friday. You'll have to wait to see measurements until then

Not a problem man, I know everybody here is actively involved in this stuff at least.

I wish I would have measured my RPW's before installing them. I believe they are 2.5" I.D. where they would meet up with the cat, but the rest I never checked. It would be an interesting comparison to see really how similar they probably both are to each other.

Go out to the car, take off the front bank, measure the primary lol.

I am really curious to see what RPW ran for Primary ID though. I wouldn't be surprised if it was still 1.5" ID and just the long tube design, but couldn't say for 100% until we got that measurement.

[boostzealot]

RPW's shorties have more primary ID than their longtubes. the only measurements i got were the OD's for both headers when i switched from the shorty headers over to the longtubes. i even saw a minor increase in power when i did the switch. the longtubes were better at scavaging and collecting than the shorties but i think there would have been more of an increase if the rear header was turned to the rear like how im doing mine now. i believe thats why the hytech's and RIPP's were a better performing set than the RPW's.

[m-rod]

Go out to the car, take off the front bank, measure the primary lol.

I'll get to it eventually. As simple as it is, I'm just burned-out right now. I think sometime within the next week or 2, I may end up checking it out.

[CMC]

RPW




collector:


to cat:


RPW vs CMF





believe it or not, but the primary OD on both sets are the same!

[Keith6110]

ha wow! thanks for the RPW measurements. It looks like cmf ID is way bigger.

[CMC]

bigger does mean better sometimes, agreed?

i think the CMF is a 2.5" collector... i could measure it if there is an interest

[SPD_FRK]

If you can, get a set of calipers and measure the insider Diameter of your RPWs so we have good "hard" numbers to run with in this post.

[CMC]

soft numbers

RPW:

primaries OD 1.5"
collector ID 2"
to cat ID 2.25"


CMF

primary OD 1.5"
collector ID 2.5"
DP/cross over pipe ID 2.25" ... and yes it trans from 2.25 to 2.5 @ the collector flange

I will try to get you hard number when am home next....

[CMC]

i got a buddy with RIPP front header... maybe i could get him to post some numbers

[boostzealot]

great documentation. i'll provide some info on why the headers are designed so differently.

with the shorty header design (RPW shorties, CMF, Megan and the like) the reason for having a much bigger section at the collector is because the scavenging process hasnt fully occured. this is good for top end power or midrange power depending on how the motor's volumetric efficiency (VE) is created. an exhaust system that compliments this setup is most beneficial because the scavenging process continues with the exhaust.

a longtube design (RPW longtubes, RIPP, and Hytech) will grant you more low end torque as the scavenging process is happening more naturally and with a greater deal of occurance. with the scanvenging occuring not only more correctly but more efficiently it enables a motor to get air out of the way faster (in terms of exhaust or spent gases), this in turn aids the motor's VE and happens to help it occur earlier. this equates to more torque down low.

hope this helps. i did a great deal of research when i was playing around with the RPW's as some of you may remember. i even compared the graphs a little bit between the two to show that i ended up with a more efficient setup with the longtubes over the shorties because of the construction of my build.

[CMC]

i got the rpws for 36 bucks on ebay

[boostzealot]

get the **** outta here are you kidding me!

[CMC]

no BS here... they were listed for a diamante by a seller that didnt have a clue... i think it was an estate sale. i bid with 4 mins left on the clock @ 9.99 and i got in a bidding war with other ebayer. i put $75 down and sat and watched the other person bid a few dollars at time... it ended at $36... it was 53 bucks shipped to my door.

http://cgi.ebay.com/ebaymotors/ws/eBayI ... &viewitem=

[m-rod]

no BS here... they were listed for a diamante by a seller that didnt have a clue... i think it was an estate sale. i bid with 4 mins left on the clock @ 9.99 and i got in a bidding war with other ebayer. i put $75 down and sat and watched the other person bid a few dollars at time... it ended at $36... it was 53 bucks shipped to my door.

http://cgi.ebay.com/ebaymotors/ws/eBayI ... &viewitem=

Whoa what! That's a steal.

[CMC]

as of right now the primaries on a RIPP set are roughly 1-3/4", my buddy is going to re-measure it... see photo

[CMC]

this is how i re-worked the DPs to work on the avenger...probably something you guys wont have to do, but here it is. am not a fan of the circle...







under the car...


on the bench...

[boostzealot]

good work but can you say ground clearance issues

[CMC]

good work but can you say ground clearance issues

yeah, am going to build a "bash guard" on the cross member to protect the tube a little bit... it hangs below the cross member about 1.5". i really think it going to be ok because its pretty much in line with the front wheels.

[Keith6110]

I don't know about the clearance part. It looks like it will get some dents in it fairly easy. Not really sure what you can really do about either except cut and re-weld pipe.

[boostzealot]

today i put together my "jig" for the headers my buddy and i will be making for the 6g series motor. the plan is to offer a midrange header that will out perform the rpw's and be more cost effective than the hytech's. they will be on an order basis with about a week or two lead time. they will go for no more than $700. i say no more than because as one's setup changes it will determine the cost of materials. so if you order 1.65" primaries then they will be less. if you order the 1.75" primaries, they will be slightly more. it also depends on whether you require o2 bungs and a flex pipe. these can also be ordered in SS or mild steel. pics to come from this set we are building for a Club3G member.