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Potential Re-Release Of Two Brothers Racing Vfr800 Headers


Rush2112

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I think a single system to meet the largest number of peoples needs would be lightweight stainless steel, center stand stop, stock angle and placement of the header discharge, O2 bungs, and performance upgrades to include equal length larger ID primaries with small convergent angle collectors (<15 degrees if possible), mimic TBR cylinder connection scheme...

I'm still waiting to hear back from Erion since our discussion on Friday he is reaching out to Yoshimura & Akropovic.

Do we have any estimate on pricing from the guy you contacted?

Agree with all of this, should we also spec the primary header size? 35mm?

I think so... is 35mm ID what we want to go with?

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I say 36 or 37.

CandyRed marked ABSOLUTELY no power loss below Vtec with 35mm primaries. how far can the design therefore be pushed?

38 MIGHT be the limit, as HRC did the RC45 like that, but!

different firing order too. so who actually knows?

I want 36 or 7. :)

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I just measured three sets of exhausts that I have laying around...

6 G - 32.2mm exterior

5G - 35.5mm exterior

TBR - 39.1mm exterior

I don't know the wall thickness of any of those but I cant imagine the TBR being less than 36mm internal diameter primaries.

I would be in favor of mimicking the TBR diameter as we see from the tuned dyno chart that it doesn't drop below 50 ft lbs of torque from 6400 rpm to 11000 rpm.

I would be concerned about a larger diameter primary robbing me of my torque since we wont be adding more rpm to the package (even with ignition tuning our V4 will not rev much beyond 12k without a good size college fund thrown at the engine work).

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I just measured three sets of exhausts that I have laying around...

6 G - 32.2mm exterior

5G - 35.5mm exterior

TBR - 39.1mm exterior

I don't know the wall thickness of any of those but I cant imagine the TBR being less than 36mm internal diameter primaries.

I would be in favor of mimicking the TBR diameter as we see from the tuned dyno chart that it doesn't drop below 50 ft lbs of torque from 6400 rpm to 11000 rpm.

I would be concerned about a larger diameter primary robbing me of my torque since we wont be adding more rpm to the package (even with ignition tuning our V4 will not rev much beyond 12k without a good size college fund thrown at the engine work).

I agree... the HRC RC45 race kitted exhaust was 38mm ID primaries but we won't see those kinds of rpms. I believe the TBR are 18ga ss so that works out to about ~1.24mm wall thickness. From external calculations that would give ~36.5mm primaries for 18ga and 35.8mm for 16 ga, but it has been reported they measured to 35mm ID like the stock RC45.

I'm ok with 36mm, more and we need more displacement or rpms... I don't know if the fabricator has an inexpensive supply of metric stainless tubing (it ain't cheap and would likely need to be ordered); but 1.5" 18 ga ss tubing will give us ~35.6mm ID primaries and 1.5" 20ga will yield ~36.3mm. I think 20 ga is too thin for primaries and 35.6 mm seems a nice incremental increase over the TBR equating to a +3.46% increase in cross sectional area of the primary

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I agree with the primary sizes and trying to stick with readily available stock SS tubing.

35.6mm is a good compromise and as long lengths are correct and matched and the collectors are a good design with good knife edges etc. we should see a reasonable return in the HP stakes.

So from my point of view, I would like:

Centre Stand to stay.

O2 bungs x 2

Same exit as standard Gen 6

Slip on stubs to fit to the heads (with springs) Not much good if we cannot guarantee matching to the ports and gaskets don't protrude in to gas flow.

Good designed collectors

Phil

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Guess what.... Talked to Erion Racing (called me on my cell). They had their headers made by an outfit in Japan. He can still source but they would be crazy expensive... spent a while talking to him and he feels for our cause. He asked specifically what we wanted and I conveyed the info that a stock exit configuration of the '98-'99 headers (angle and placement) would allow the headers to fit 1998 - 2009 + 2014 - ????. He wants to help and he is calling his friends at Yoshimura & Akropovic to see if they can work something out. I told him we already had 10 - 15 people interested and that seemed to be enough.

I'll keep you posted...

Where's that fingers crossed emoticon!!!

I am definitely interested, but I think that 100 orders from 2bros is a bit much. Keep us posted!

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This.

.050" wall tubing would be the common 'murican size to look for (1.25mm wall).

I agree with the primary sizes and trying to stick with readily available stock SS tubing.

35.6mm is a good compromise and as long lengths are correct and matched and the collectors are a good design with good knife edges etc. we should see a reasonable return in the HP stakes.

So from my point of view, I would like:

Centre Stand to stay.

O2 bungs x 2

Same exit as standard Gen 6

Slip on stubs to fit to the heads (with springs) Not much good if we cannot guarantee matching to the ports and gaskets don't protrude in to gas flow.

Good designed collectors

Phil

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This.

.050" wall tubing would be the common 'murican size to look for (1.25mm wall).

I agree with the primary sizes and trying to stick with readily available stock SS tubing.

35.6mm is a good compromise and as long lengths are correct and matched and the collectors are a good design with good knife edges etc. we should see a reasonable return in the HP stakes.

So from my point of view, I would like:

Centre Stand to stay.

O2 bungs x 2

Same exit as standard Gen 6

Slip on stubs to fit to the heads (with springs) Not much good if we cannot guarantee matching to the ports and gaskets don't protrude in to gas flow.

Good designed collectors

Phil

Yup... that's 18 gauge (0.049", 1.2446 mm) according to SPDexhausts

I want at least 36mm ID. period. the end.

Next size up in standard tubing size in 18ga would result in ~39mm ID primaries... way too big

16ga would yield ~38.2mm... still too big and heavier

... bigger isn't always better

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Guess what.... Talked to Erion Racing (called me on my cell). They had their headers made by an outfit in Japan. He can still source but they would be crazy expensive... spent a while talking to him and he feels for our cause. He asked specifically what we wanted and I conveyed the info that a stock exit configuration of the '98-'99 headers (angle and placement) would allow the headers to fit 1998 - 2009 + 2014 - ????. He wants to help and he is calling his friends at Yoshimura & Akropovic to see if they can work something out. I told him we already had 10 - 15 people interested and that seemed to be enough.

I'll keep you posted...

Where's that fingers crossed emoticon!!!

I am definitely interested, but I think that 100 orders from 2bros is a bit much. Keep us posted!

We've moved beyond 2Bros and are looking at going with another manufacturer who will do smaller runs. http://www.hiperform.com/new_page_3.htm
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next size up, but a lil thicker then?

Probably should be asking Rod about what can be done to achieve a 36mm primary, rather than assume a standard?

... that's what 16ga is, a little thicker (+0.41mm thicker wall than 18 ga)

non standard sized stainless tubing is very expensive. We are already looking at paying for a small run, custom exhaust where the labor and expertise is expensive... adding expensive materials could double the price.

What sized secondaries ID would you use with a 36mm or greater primaries and how would this feed into the stock sized header collector discharge? It is not just about the primaries... the exhaust velocity and volume need to work with the pipe volume changes downstream to prevent undesired reflected waves that reduce exhaust gas scavenging and reduce efficient gas flow

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18 gauge 304 stainless steel with 1.5" tubing primaries, 1.63" tubing secondaries, 2.0" header collector discharge results in:

~35.6 mm ID primaries

~39 mm ID secondaries

~49mm ID header collector discharge

According to my searches and data collection for the past year and a half RC45 & TBR headers specs are:

~35 mm ID primaries

~39 mm ID secondaries

~49mm ID header collector discharge

I propose these specs as the closest to known performance race headers with documented results using commercially available materials to keep costs down... and there is ~3.5% bump in primary header area over the TBR and RC45

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What is the ID of people's slip-on mid-pipes that they want to retain?

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FYI my two brothers racing full system mid pipe and two brothers slip on are an exact match in inner and outer diameter, thickness etc....

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I think a single system to meet the largest number of peoples needs would be lightweight stainless steel, center stand stop, stock angle and placement of the header discharge, O2 bungs, and performance upgrades to include equal length larger ID primaries with small convergent angle collectors (<15 degrees if possible), mimic TBR cylinder connection scheme...

I'm still waiting to hear back from Erion since our discussion on Friday he is reaching out to Yoshimura & Akropovic.

Do we have any estimate on pricing from the guy you contacted?

Yep, I would buy that. I haven't put my hand up for these because I'm not keen on a full system per se & I'm already committed to few other expensive parts at the moment, but if someone made that in the future, I would buy one.

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FYI my two brothers racing full system mid pipe and two brothers slip on are an exact match in inner and outer diameter, thickness etc....

Sent from my iPhone using Tapatalk

what are the ID & OD?

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now that it's explained out, I'm done freaking out hahaha ^_^

Maybe a midpipe is in order, but we will see. I'll have another talk with rod, and maybe measure my stock midpipe, and see what's up.

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Have we come to a general consensus to hand to Rod? I told him we would try and get him an answer this week, not rushing anyone, just wanted to get back to him and give him an update. At least it shows we are still interested and not just blowing smoke.

Also, has the list of interested folks changed, now that 2Bros is not the shop going to be providing the kit, has anyone changed their mind?

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I'm still in, and I'll have to admit I'm a bit more up for it than I was. I'm not knowledgeable enough about OD and ID of tubing so I'll go with whatever is decided. I would like the retain the center stand, stock header pipe outlet position, stainless tubing, and the stubs out of the exhaust ports.

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I think a single system to meet the largest number of peoples needs would be lightweight stainless steel, center stand stop, stock angle and placement of the header discharge, O2 bungs, and performance upgrades to include equal length larger ID primaries with small convergent angle collectors (<15 degrees if possible), mimic TBR cylinder connection scheme...

I'm still waiting to hear back from Erion since our discussion on Friday he is reaching out to Yoshimura & Akropovic.

Do we have any estimate on pricing from the guy you contacted?

This.

.050" wall tubing would be the common 'murican size to look for (1.25mm wall).

I agree with the primary sizes and trying to stick with readily available stock SS tubing.

35.6mm is a good compromise and as long lengths are correct and matched and the collectors are a good design with good knife edges etc. we should see a reasonable return in the HP stakes.

So from my point of view, I would like:

Centre Stand to stay.

O2 bungs x 2

Same exit as standard Gen 6

Slip on stubs to fit to the heads (with springs) Not much good if we cannot guarantee matching to the ports and gaskets don't protrude in to gas flow.

Good designed collectors

Phil

18 gauge 304 stainless steel with 1.5" tubing primaries, 1.63" tubing secondaries, 2.0" header collector discharge results in:

~35.6 mm ID primaries

~39 mm ID secondaries

~49mm ID header collector discharge

According to my searches and data collection for the past year and a half RC45 & TBR headers specs are:

~35 mm ID primaries

~39 mm ID secondaries

~49mm ID header collector discharge

I propose these specs as the closest to known performance race headers with documented results using commercially available materials to keep costs down... and there is ~3.5% bump in primary header area over the TBR and RC45

I think the above has outlined the most promising results to reach the greatest number of potential buyers.

This should be communicated to Rod and we go from there.

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I think a single system to meet the largest number of peoples needs would be lightweight stainless steel, center stand stop, stock angle and placement of the header discharge, O2 bungs, and performance upgrades to include equal length larger ID primaries with small convergent angle collectors (<15 degrees if possible), mimic TBR cylinder connection scheme...

I'm still waiting to hear back from Erion since our discussion on Friday he is reaching out to Yoshimura & Akropovic.

Do we have any estimate on pricing from the guy you contacted?

This.

.050" wall tubing would be the common 'murican size to look for (1.25mm wall).

I agree with the primary sizes and trying to stick with readily available stock SS tubing.

35.6mm is a good compromise and as long lengths are correct and matched and the collectors are a good design with good knife edges etc. we should see a reasonable return in the HP stakes.

So from my point of view, I would like:

Centre Stand to stay.

O2 bungs x 2

Same exit as standard Gen 6

Slip on stubs to fit to the heads (with springs) Not much good if we cannot guarantee matching to the ports and gaskets don't protrude in to gas flow.

Good designed collectors

Phil

18 gauge 304 stainless steel with 1.5" tubing primaries, 1.63" tubing secondaries, 2.0" header collector discharge results in:

~35.6 mm ID primaries

~39 mm ID secondaries

~49mm ID header collector discharge

According to my searches and data collection for the past year and a half RC45 & TBR headers specs are:

~35 mm ID primaries

~39 mm ID secondaries

~49mm ID header collector discharge

I propose these specs as the closest to known performance race headers with documented results using commercially available materials to keep costs down... and there is ~3.5% bump in primary header area over the TBR and RC45

I think the above has outlined the most promising results to reach the greatest number of potential buyers.

This should be communicated to Rod and we go from there.

I agree...

Wait a minute... isn't the center stand stop on the mid-pipe not the header?!? On my 5th gen it is on the muffler assembly pipe not the header... can a 6th gen owner confirm location of center stand stop? This may be outside the scope of work for the custom headers...

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Personally, I'd like to see a SS system that uses the stock exit point so I don't have to do additional fabrication in order to accomodate my TBR exhaust. It's also got to be compatible with the center stand, preferably with a center stand stop in place, & O2 bungs. I'd also prefer to have a system that mimic's the TBR pipe as closely as possible while maintaining the above. And yes I'm still interested.

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The center stand stop on all cat equipped bikes is located on the back edge of the cat.

On non-cat bikes it is located on what would be the mid pipe of a high mount system.

For this application (to keep the maximum number of exhaust exit configurations possible) the center stand stop should be on the header.


Personally, I'd like to see a SS system that uses the stock exit point so I don't have to do additional fabrication in order to accomodate my TBR exhaust. It's also got to be compatible with the center stand, preferably with a center stand stop in place, & O2 bungs. I'd also prefer to have a system that mimic's the TBR pipe as closely as possible while maintaining the above. And yes I'm still interested.

Please let us know what you are looking for in the way of specs if the 3-5 quoted posts above do not cover it. As I read your wish list it looks like you are right in the center of our target spec.

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Regardless of the outlet angle I think the exhaust stop would end up on the mid-pipe, either low or high mount.

I'm still in, and I'll have to admit I'm a bit more up for it than I was. I'm not knowledgeable enough about OD and ID of tubing so I'll go with whatever is decided. I would like the retain the center stand, stock header pipe outlet position, stainless tubing, and the stubs out of the exhaust ports.

If we're talking a SS set with all FJ listed, I might be in too. The outlet is the deal breaker for me, it would need to be OEM positioned. Not sure what stubs though?

If this does come to pass, anyone want to buy a clean, vintage, original generation TBros SS full exhaust?

:wink:

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