[grymattr]

This is a question to all the makers, manufacturers and creators of catless downpipes. I see all the different makers, all the different welds, types, etc.

Is there a reason they just don't mandrel bend them? Seems like it would require no welds. Now mind you, I'm only about 20% knowledgable about this stuff so please don't flame me.

Is it cost? Complexity to the bends, cost of a mandrel bender?

I'm just curious and would like a logical response.

Thank you.

[Mattscott]

Riss Racing Dp's are mandrel bent.

[asdflkijd]

Originally Posted by Mattscott

Riss Racing Dp's are mandrel bent.

no they aren't. they are welded, just like the ones from UR... if you mandrel bend the pipes, they will cause creases or wrinkles if you will, and which will disturb the airflow....

[Mr. 5]

Originally Posted by Mattscott

Riss Racing Dp's are mandrel bent.

They aren't mandrel bent.
This is one of the things that pissed me off so much when the pipes finally came out. It was completely false advertising in my book, and I don't care how much they disagree with me on this.

They polished all of the welds on the outside to make it look like everything was mandrel bent and they posted pictures of these "completely mandrel bent" pipes. People were complaining when they received the pipes and they were wondering why there were welds inside the pipe.
I believe that somebody counted a total of 9 welds that were performed.

To answer your question, I will give you the answer that was given to me by Riss Racing--"That would be way too expensive if they were completely mandrel bent."

[DrewKo]

Wow, I am shocked...Riss flat out called their catless pipes mandrel bent pipes without qualification. That's disgusting in my humble opinion. Makes me question Riss as a product supplier/business.

[Mattscott]

Sorry guys, I just remember them saying they were mandrel bent. MY BAD.

And my .02 I'd rather have the welds on the outside of the dp's then on the inside. <3 UR

[Mattscott]

Originally Posted by DrewKo

Wow, I am shocked...Riss flat out called their catless pipes mandrel bent pipes without qualification. That's disgusting in my humble opinion. Makes me question Riss as a product supplier/business.

Wanna hear something funny, my sig said i was going to get UR dp's. Riss racing sent me a PM saying I should buy their product, as they would sell it to me cheaper then "the competition". That is very very low IMO

[O-cha]

For those of you who don't know mandrel bending is a very specific process used to bend pipe as to keep it very smooth. However the term is used to refer to pipes that are bent in manners other then the technical mandrel bending technique that achieve the same results. Probably 80% of the stuff advertised as mandrel bent isn't actually mandrel bent, but is in effect the exact same thing.

Stuff like this is pretty much the only thing that wouldn't be referred to as mandrel bent.

[roozie2001]

yah but the what they're saying is don't advertise the product as mandrel bent if its not. i used to have an AEM CAI on another car that was mandrel bent and it made a for more airflow, power, better throttle response than any other product that wasn't. Its bad for business to advertise something that its not.

[nd54]

Why is everyone so shocked these companies are making false claims about a product? They're all new, have no history, and little to no experience with BMW's. It's amazing what these forums can do for some no-name brand by making a few posts.

[Orb]

Originally Posted by Mr. 5

They aren't mandrel bent.
This is one of the things that pissed me off so much when the pipes finally came out. It was completely false advertising in my book, and I don't care how much they disagree with me on this.

They polished all of the welds on the outside to make it look like everything was mandrel bent and they posted pictures of these "completely mandrel bent" pipes. People were complaining when they received the pipes and they were wondering why there were welds inside the pipe.
I believe that somebody counted a total of 9 welds that were performed.

To answer your question, I will give you the answer that was given to me by Riss Racing--"That would be way too expensive if they were completely mandrel bent."

The tubes are mandrel bent but only in small sections. They most likely bought it this way or had a few custom pieces made.

There no expansion section in these pipe which kind means drop the ball. Supersprint has them in thier pipes but thye have no hangers?

Orb

[roozie2001]

Originally Posted by nd54

Why is everyone so shocked these companies are making false claims about a product? They're all new, have no history, and little to no experience with BMW's. It's amazing what these forums can do for some no-name brand by making a few posts.

+1

[astris]

Originally Posted by Mr. 5

They aren't mandrel bent.
This is one of the things that pissed me off so much when the pipes finally came out. It was completely false advertising in my book, and I don't care how much they disagree with me on this.

They polished all of the welds on the outside to make it look like everything was mandrel bent and they posted pictures of these "completely mandrel bent" pipes. People were complaining when they received the pipes and they were wondering why there were welds inside the pipe.
I believe that somebody counted a total of 9 welds that were performed.

To answer your question, I will give you the answer that was given to me by Riss Racing--"That would be way too expensive if they were completely mandrel bent."

Wow, thanks for the clarification. I have told others that there were completely mandrel bent.

I apologize to those I accidentally mislead. I was just regurgitating info I had read.

[trueblue]

Originally Posted by asdflkijd

no they aren't. they are welded, just like the ones from UR... if you mandrel bend the pipes, they will cause creases or wrinkles if you will, and which will disturb the airflow....

Please don't comment on things you do not have any ideas about.
It constantly amazes me how much mis-information is on this board.
The advantage of mandrel bending is because it does NOT cause creasing or wrinkles. The bends are constant radius therefor will not introduce flow disturbance. A decent 3 axis mandrel machine can cost more than 100K.

[roozie2001]

just talked to a buddy of mine thats welder. and depending on the weld the downpipes can be ok. Like trueBlue said the mandrel machines are very expensive and not all of these small companies have that capital. As long as they are getting mandrel pieces and are TIG Welding them together then your ok. Because the TIG weld is smooth and unharmed on the inside and rough on the outside. So i think next time you buy an intake or DP ask the dealer. Is your product mandrel bent or mandrel pieces welded together? and if it is welded. What kinda weld is it? If its a TIG weld then your good to go.

[asdflkijd]

Originally Posted by trueblue

Please don't comment on things you do not have any ideas about.
It constantly amazes me how much mis-information is on this board.
The advantage of mandrel bending is because it does NOT cause creasing or wrinkles. The bends are constant radius therefor will not introduce flow disturbance. A decent 3 axis mandrel machine can cost more than 100K.

if I am "misinformed" then why not just correct me instead of being a smart ass? I am just passing on information that I read from this board. nonetheless, they aren't mandrel bent.

[grymattr]

Originally Posted by trueblue

Please don't comment on things you do not have any ideas about.
It constantly amazes me how much mis-information is on this board.
The advantage of mandrel bending is because it does NOT cause creasing or wrinkles. The bends are constant radius therefor will not introduce flow disturbance. A decent 3 axis mandrel machine can cost more than 100K.

I didn't mean to start a war here, I simply wanted the answer and now I believe I have it. I've seen many samples of mandrel bent pipe and have watched it being done, I thought if done properly it was the best way to achieve the end result for a good downpipe due the very reasons listed above.

Thank you for your input, now back to your regularly scheduled flame war.


Dean

[Ultimate Racing]

Good post.

Mandrel benders work great, but can't always replace good old fashioned welding techniques (eg. pie slicing). The majority of the affordable mandrel benders on the market can only bend a tube so tightly. Certain products, like 335 Downpipes, require a much tighter bend than a mandrel bender can produce. This is why we need to cut and weld these sections. Another reason why a mandrel bender isn't always the best option is because of the machine's grab area. Most mandrel benders need a certain amount of straight tubing before it can produce the next bend. This why you never see a tight bend right after another tight bend on a mandrel bent piece. When you do see pieces like these, investigate further. You'll probably find that the piece has been welded, grinded, and polished to appear to be completely one piece.

Here's an example of a cut and welded piece we make for the Lancer Evolution that could never be produced by a mandrel bender:



Interestingly enough, we've never had Evo customers complain about "pie slicing" techniques. They absolutely love the hand fabricated look.

We also don't often use mandrel bends to cut and weld. Like some have already mentioned, mandrel benders don't always give the most uniform product. Majority of the time, they leave the tubing with ripples/wrinkles, and/or not quite round. When we cut into these mandrel bends we 're actually left with something more oval than round. This just looks hideous when we try to weld it onto a perfect round pipe section.

We almost always use 304 stainless, casted elbows.





These are 100% uniform throughout, smooth as hell, and can be made with a much tighter center line radius (ie. tighter bend).


Hope I've answered some questions.

Darryl
www.ultimate-racing.com

[Ultimate Racing]

Originally Posted by Mattscott

Wanna hear something funny, my sig said i was going to get UR dp's. Riss racing sent me a PM saying I should buy their product, as they would sell it to me cheaper then "the competition". That is very very low IMO

Darryl
www.ultimate-racing.com

[hotrod2448]

Originally Posted by Ultimate Racing

Good post.

Mandrel benders work great, but can't always replace good old fashioned welding techniques (eg. pie slicing). The majority of the affordable mandrel benders on the market can only bend a tube so tightly. Certain products, like 335 Downpipes, require a much tighter bend than a mandrel bender can produce. This is why we need to cut and weld these sections. Another reason why a mandrel bender isn't always the best option is because of the machine's grab area. Most mandrel benders need a certain amount of straight tubing before it can produce the next bend. This why you never see a tight bend right after another tight bend on a mandrel bent piece. When you do see pieces like these, investigate further. You'll probably find that the piece has been welded, grinded, and polished to appear to be completely one piece.

Here's an example of a cut and welded piece we make for the Lancer Evolution that could never be produced by a mandrel bender:



Interestingly enough, we've never had Evo customers complain about "pie slicing" techniques. They absolutely love the hand fabricated look.

We also don't often use mandrel bends to cut and weld. Like some have already mentioned, mandrel benders don't always give the most uniform product. Majority of the time, they leave the tubing with ripples/wrinkles, and/or not quite round. When we cut into these mandrel bends we 're actually left with something more oval than round. This just looks hideous when we try to weld it onto a perfect round pipe section.

We almost always use 304 stainless, casted elbows.





These are 100% uniform throughout, smooth as hell, and can be made with a much tighter center line radius (ie. tighter bend).


Hope I've answered some questions.

Darryl
www.ultimate-racing.com

He speaks the truth.

Welds are not a bad thing if they are done right.

[Mr. 5]

Thanks for the informative post Darryl.

Originally Posted by Ultimate Racing

Good post.

Mandrel benders work great, but can't always replace good old fashioned welding techniques (eg. pie slicing). The majority of the affordable mandrel benders on the market can only bend a tube so tightly. Certain products, like 335 Downpipes, require a much tighter bend than a mandrel bender can produce. This is why we need to cut and weld these sections. Another reason why a mandrel bender isn't always the best option is because of the machine's grab area. Most mandrel benders need a certain amount of straight tubing before it can produce the next bend. This why you never see a tight bend right after another tight bend on a mandrel bent piece. When you do see pieces like these, investigate further. You'll probably find that the piece has been welded, grinded, and polished to appear to be completely one piece.

Here's an example of a cut and welded piece we make for the Lancer Evolution that could never be produced by a mandrel bender:



Interestingly enough, we've never had Evo customers complain about "pie slicing" techniques. They absolutely love the hand fabricated look.

We also don't often use mandrel bends to cut and weld. Like some have already mentioned, mandrel benders don't always give the most uniform product. Majority of the time, they leave the tubing with ripples/wrinkles, and/or not quite round. When we cut into these mandrel bends we 're actually left with something more oval than round. This just looks hideous when we try to weld it onto a perfect round pipe section.

We almost always use 304 stainless, casted elbows.





These are 100% uniform throughout, smooth as hell, and can be made with a much tighter center line radius (ie. tighter bend).


Hope I've answered some questions.

Darryl
www.ultimate-racing.com

[Geezer]

Originally Posted by Ultimate Racing

Most mandrel benders need a certain amount of straight tubing before it can produce the next bend. This why you never see a tight bend right after another tight bend on a mandrel bent piece. When you do see pieces like these, investigate further. You'll probably find that the piece has been welded, grinded, and polished to appear to be completely one piece.

Sounds exactly like the Riss "one piece" DP.
Good post