header / max boost ?

[KnappAttack]

imo the header is worth the investment alone to get rid of the problematic flex joint that always cracks after 3-4000miles.

What about when the header cracks?

I've never seen a header yet NOT crack. We used to crack them all the time on the turbo RX-1 and Apexs, Even cracked them on stock 1200's as well as the turbos, and they usually are almost impossible to weld up. Have to replace them more often then not. Ted was building manifolds to stand up to the abuse rather than cracking headers all the time and having to deal with that headache.

Is the flex a known issue? I know a couple that have. How much to replace the flex pipe?

I had a good friend that took all the headers they installed off a bunch of 998's due to his own sled going up in flames, doesn't know for certainty it was the header that caused it, but wasn't wowed by the power and not worth the risk if it was the cause. He stated they were no faster than stock manifold 998's if at all. His report, nothing I've seen myself, but I trust his word. He is now running stock manifold again with no issues and no desire to go back to a header on a trail sled, says he won't do it again.

 

[74Nitro]

What about when the header cracks?

I've never seen a header yet NOT crack. We used to crack them all the time on the turbo RX-1 and Apexs, Even cracked them on stock 1200's as well as the turbos, and they usually are almost impossible to weld up. Have to replace them more often then not. Ted was building manifolds to stand up to the abuse rather than cracking headers all the time and having to deal with that headache.

Is the flex a known issue? I know a couple that have. How much to replace the flex pipe?

I had a good friend that took all the headers they installed off a bunch of 998's due to his own sled going up in flames, doesn't know for certainty it was the header that caused it, but wasn't wowed by the power and not worth the risk if it was the cause. He stated they were no faster than stock manifold 998's if at all. His report, nothing I've seen myself, but I trust his word. He is now running stock manifold again with no issues and no desire to go back to a header on a trail sled, says he won't do it again.

I really appreciate that info Mike as I was considering a header.
With that fuel tank in close proximity the last thing anyone wants is a header leaking or cracking.
I guess there is a reason Yamaha opted to go cast.

 

[snowcaine]

I really appreciate that info Mike as I was considering a header.
With that fuel tank in close proximity the last thing anyone wants is a header leaking or cracking.
I guess there is a reason Yamaha opted to go cast.

The header fits under the stock heat shields with only a little massaging. The shields still completely cover the header. I also put 2,000 F heat reflective tape on the gas tank portions that face the heat shields. There are also slots in the tunnel under the heat shields that allow heat to vent toward the track. I believe the reason the main heat shield extends so far rearward is to cover more of the tunnel slots to dissipate additional heat. As the track spins, it pulls heat down through the tunnel slots or, at the very least, circulates a lot of air through the tunnel slots, thus cooling the header/manifold. Bottom line: I doubt a sled is burning up because of a cracked or leaky header. Of course, I could be wrong or mistaken.

 

[KnappAttack]

I really appreciate that info Mike as I was considering a header.
With that fuel tank in close proximity the last thing anyone wants is a header leaking or cracking.
I guess there is a reason Yamaha opted to go cast.

Also the reason I decided to try a SideWinder and the 998, the cast manifold is way less likely to crack. Heavy, but less issues, and I've been down the craking road before... The stock flex could however be an issue, but a quick easy replacement is an easy fix there. I've seen a few so far but far from a rash of them. If the boost suddenly goes away we'll know why. Of course you'll hear the exhaust leak too.

Not many headers out there yet, but you'll see, they will crack in time. Always have, and always will.

 

[ClutchMaster]

What about when the header cracks?

I've never seen a header yet NOT crack. We used to crack them all the time on the turbo RX-1 and Apexs, Even cracked them on stock 1200's as well as the turbos, and they usually are almost impossible to weld up. Have to replace them more often then not. Ted was building manifolds to stand up to the abuse rather than cracking headers all the time and having to deal with that headache.

Is the flex a known issue? I know a couple that have. How much to replace the flex pipe?

I had a good friend that took all the headers they installed off a bunch of 998's due to his own sled going up in flames, doesn't know for certainty it was the header that caused it, but wasn't wowed by the power and not worth the risk if it was the cause. He stated they were no faster than stock manifold 998's if at all. His report, nothing I've seen myself, but I trust his word. He is now running stock manifold again with no issues and no desire to go back to a header on a trail sled, says he won't do it again.

Absolutely, that is a major concern with the exhaust under the tank. The heat shielding helps but I believe the blankets that wrap them are a good second line of defense too. I have had good luck making my headers out of 321 stainless and ceramic coating them. It’s twice as expensive as 304 stainless so it’s not likely these production headers are made from 321.
321 stainless only prolongs the eventual crack, Mike is correct, inspection of your header should be a maintenance item done several times a year if your trail riding with a header on a turbo because the headers get much hotter than a N/A header.

Running the stock muffler is definitely going to detract from performance. At minimum I would run the modified stock muffler to improve the header gains. Buying a $900 header and not pairing it with a better flowing muffler seems moot.

 

[snowcaine]

That’s exactly what is happening ^^^^

This I what happens when you add the header.
There’s more airflow through the turbo at a lower boost level. You can lock the wastegate but it probably won’t help more than a pound or two. Once the airflow is maxed out on a turbo, efficiency drops significantly and it begins to overspeed heating the air substantially, not good. This is common on smaller turbocharged vehicles, the boost will start dropping as rpm increases. Turbo is maxed out.
Airflow is what determines horsepower not boost level. Since the boost is actually lower your octane requirement is also lower, good thing.
Rest assured there’s more airflow with the header and its at a lower boost level, all good things imo.

ClutchMaster, how/why does increased airflow from the header translate into lower boost? Wouldn’t increased airflow spin the turbo faster resulting in greater boost? In your opinion is the header a net positive or negative for hp and seat of the pants feel? Sorry just trying to understand this. Thanks.

 

[sledding rocks]

fyi guys ,
talked with the guys at td , ben is currently working on tunes for the header , soon to be released , max 17 will produce boost at 17.3 , and max 20 at 18.3 , adding more hp ,
as for the stainless header it self , we all no it will crack in time , what is that time 10,000 ,20,000 miles who knows , one thing I can add the header does work and flows more then the stock manifold , a/f proved that , as for the fit of the header , I'm now using td header , the fit and clearance is excellent with no issues ,
I had the other tuners header last season , all I can say is the clearance is not enough between the header and fuel tank which melted my fuel tank , not good , the header is a performance part weather u want it or not its your choice .

 

[ClutchMaster]

ClutchMaster, how/why does increased airflow from the header translate into lower boost? Wouldn’t increased airflow spin the turbo faster resulting in greater boost? In your opinion is the header a net positive or negative for hp and seat of the pants feel? Sorry just trying to understand this. Thanks.

This is a turbo compressor map, it shows airflow on the X axis and boost pressure on the Y axis, it’s in absolute pressure so 2 Bar is 14.5 psi boost 3 Bar would be 29 psi boost, ect.

It’s not the graph for a Winder Turbo but good enough for example. Take the pressure ratio of 2.5 follow the line over to 48 lbs min airflow line. As you can see the efficiency lines (choke line) are basically straight up and down. Forcing this turbo to boost up to 3.0 Bar will offer no added airflow even tho the turbo is spinning faster, all it will do is increase intake air temps. this to can actually make the boost gauge read higher because intake temps have increased, Same amount of airflow at a higher temperature takes up more space equaling more boost, remember we are talking about airflow here.

Most of the boost decrease is just due to the fact air flows through the engine more easily so it takes less boost to push the same amount of air through it. When the turbo is maxed out this is common to see. Less boost can add more horsepower because intake air temps will be lower along with lower boost pressure so timing will be higher in the tune with less chance for detonation.

I’ll add that the compressor map shown is for a larger turbo than the Winder turbo. Larger turbos with bigger wheels can boost more pressure. If this were a map of the Winder Turbo it would likely not even be charted up to 3 Bar pressure ratio.

 

[snowcaine]

View attachment 152450

This is a turbo compressor map, it shows airflow on the X axis and boost pressure on the Y axis, it’s in absolute pressure so 2 Bar is 14.5 psi boost 3 Bar would be 29 psi boost, ect.

It’s not the graph for a Winder Turbo but good enough for example. Take the pressure ratio of 2.5 follow the line over to 45 lbs min airflow line. As you can see the efficiency lines are basically straight up and down. Forcing this turbo to boost up to 3.0 Bar will offer no added airflow even tho the turbo is spinning faster, all it will do is increase intake air temps. this to can actually make the boost gauge read higher because intake temps have increased, Same amount of airflow at a higher temperature takes up more space equaling more boost, remember we are talking about airflow here.

Most of the boost decrease is just due to the fact air flows through the engine more easily so it takes less boost to push the same amount of air through it. When the turbo is maxed out this is common to see. It does add horsepower because intake air temps will be lower along with lower boost pressure so timing will be higher in the tune with less chance for detonation.

I’ll add that the compressor map shown is for a larger turbo than the Winder turbo. Larger turbos with bigger wheels can boost more pressure. If this were a map of the Winder Turbo it wouldn’t likely even be charted up to 3 Bar pressure ratio.

Well after reading this a half dozen times and standing on my head, I believe I understand now why a freer flowing header and less boost can actually be better for the engine. Thank you for the explanation and your knowledge.

Now, what are your thoughts on the Bikeman bigger wheel or that Hurricane monster turbo? Good, bad, problematic? Thanks.

 

[DooZ]

We haven't heard much from TD lately, I'm surprised Ben hasn't chimed in more.

 

[DMCTurbo]

We haven't heard much from TD lately, I'm surprised Ben hasn't chimed in more.

Ya he's pretty silent this year.

 

[ClutchMaster]

Well after reading this a half dozen times and standing on my head, I believe I understand now why a freer flowing header and less boost can actually be better for the engine. Thank you for the explanation and your knowledge.

Now, what are your thoughts on the Bikeman bigger wheel or that Hurricane monster turbo? Good, bad, problematic? Thanks.

Not sure about those turbos.

I’m positive that a header will help in my case so I’m just going to make one with nice long tubes and equal lengths.

Now it’s time to get some welding practice!

 

[snowcaine]

Not sure about those turbos.

I’m positive that a header will help in my case so I’m just going to make one with nice long tubes and equal lengths.

View attachment 152466 View attachment 152467

Now it’s time to get some welding practice!

That’s awesome nice work! Looking forward to seeing the final product!

 

[1nc 2000]

Not sure about those turbos.

I’m positive that a header will help in my case so I’m just going to make one with nice long tubes and equal lengths.

View attachment 152466 View attachment 152467

Now it’s time to get some welding practice!

Looks good. Cat should have made the sidewinder heat exchanger flange come up the tunnel like it is on your viper.

 

[Fleecer]

Nice work CM!!