Test results.. "Big" CT Black vs CT Black
Posted: Sun Oct 23, 2011 7:35 pm
Test results... ÔÇ£BigÔÇØ CT Black verses Bears CT black
Bear was kind enough to send me his CT Black intake/reed setup with the 2 petal carbon fiber reeds to test along side a out of the box ÔÇ£bigÔÇØ CT Black that Darin sent me.
Visual observations
The ÔÇ£BigÔÇØ CT Black is just that... bigger. It has a larger internal volume.. and can accept a larger reed block package than the smaller one can. Because of the extra volume the out side mounting bolts have to come from the bottom of the manifold meaning some case modifications have to be done before using the ÔÇ£BigÔÇØ manifold setup.
The reeds appear to be fiber glass and have factory installed spring steel reed ÔÇ£fingerÔÇØ springs and reed stops. Looks like improvements can be easily made by removing the springs and stops and going with CF reeds or the after market reed setups that are available for this size intake.
Bears version of the CT Black seems to be a lower half of the std CT with a 2 petal CF reed and a different upper piece that uses the bolt on rubber carb adapter like the ÔÇ£BigÔÇØ CT Black. Bears upper section appears to have been modified and smoothed out to improve flow... doesnÔÇÖt look like a factory modification.
Bears reeds have no reed stops or finger springs on the reeds and because of this it is set for maximum flow.
The Test
I machined a flat plate to the Honda intake size using a stock gasket as a template. The manifolds were bolted to this plate and attached to the flow bench for testing.
No carb was used during testing and both manifolds used the same size carb adapter.. although the ÔÇ£BigÔÇØ CT comes with a optional larger rubber manifold to accept larger carbs I didnt use it to keep the test equal as possible.
All tests were done at 15 inches.
Results
Out of the box Bears manifold passed 59 cfm
'BigÔÇØ CT Black 57 cfm
Win for Bear
Next test I removed the stock ÔÇ£finger springs and reed stopsÔÇØ from the Big CT
and it improved to 88.7cfm
Win for ÔÇ£BigÔÇØ CT
Next I put in a 4 petal CF reed block (no finger springs) made for a std CT manifold into Bears setup and the flow dropped to 55.5 cfm.
This proves that Bears theory about the two big reeds flowing more than 4 (or more) smaller
is true (although I for got to remove the reed stops)... doh.
I didnt have a aftermarket V Force setup to test but I believe it would flow more yet in the ÔÇ£Big CT
I then tested both intakes with out the reed blocks installed. This number compared to the best flow number with reed blocks installed will tell us how much each reed setup restricts flow.
Since booth inlet and exit sizes were the same it didnÔÇÖt surprise me that they flowed almost the same.
Bears 93.9 cfm
BIG 95.0 cfm
Conclusions
Bears CT Black with the 2 petal CF reeds setup is better the the Std CT most of us run.. even if you run the optional CF reeds with the finger springs removed. Also I cant see anywhere you can improve this setup.. IMHO its maxed out as tested.
But while the ÔÇ£BigÔÇØ CT Black flows slightly less out of the box it flows substantially more by simply removing the ÔÇ£fingerÔÇØ springs and reed stops.
I think it has still more untapped potential using a better after market reed setup that you cant fit in the smaller Black.
As you can see from the ÔÇ£No reed blockÔÇØ test the smaller manifold is held back by the smaller reed block area available and the smaller area around the reeds that seems to restrict the flow.
In my opinion if your motor can benefit from more intake flow the ÔÇ£BigÔÇØ is the better manifold system. Now how big a motor you need to benefit from the increased flow will have to be proven at the track.... I can only show you which one flows more air.
Special thanks to Bear who graciously sent me his manifold for testing!!
Bear was kind enough to send me his CT Black intake/reed setup with the 2 petal carbon fiber reeds to test along side a out of the box ÔÇ£bigÔÇØ CT Black that Darin sent me.
Visual observations
The ÔÇ£BigÔÇØ CT Black is just that... bigger. It has a larger internal volume.. and can accept a larger reed block package than the smaller one can. Because of the extra volume the out side mounting bolts have to come from the bottom of the manifold meaning some case modifications have to be done before using the ÔÇ£BigÔÇØ manifold setup.
The reeds appear to be fiber glass and have factory installed spring steel reed ÔÇ£fingerÔÇØ springs and reed stops. Looks like improvements can be easily made by removing the springs and stops and going with CF reeds or the after market reed setups that are available for this size intake.
Bears version of the CT Black seems to be a lower half of the std CT with a 2 petal CF reed and a different upper piece that uses the bolt on rubber carb adapter like the ÔÇ£BigÔÇØ CT Black. Bears upper section appears to have been modified and smoothed out to improve flow... doesnÔÇÖt look like a factory modification.
Bears reeds have no reed stops or finger springs on the reeds and because of this it is set for maximum flow.
The Test
I machined a flat plate to the Honda intake size using a stock gasket as a template. The manifolds were bolted to this plate and attached to the flow bench for testing.
No carb was used during testing and both manifolds used the same size carb adapter.. although the ÔÇ£BigÔÇØ CT comes with a optional larger rubber manifold to accept larger carbs I didnt use it to keep the test equal as possible.
All tests were done at 15 inches.
Results
Out of the box Bears manifold passed 59 cfm
'BigÔÇØ CT Black 57 cfm
Win for Bear
Next test I removed the stock ÔÇ£finger springs and reed stopsÔÇØ from the Big CT
and it improved to 88.7cfm
Win for ÔÇ£BigÔÇØ CT
Next I put in a 4 petal CF reed block (no finger springs) made for a std CT manifold into Bears setup and the flow dropped to 55.5 cfm.
This proves that Bears theory about the two big reeds flowing more than 4 (or more) smaller
is true (although I for got to remove the reed stops)... doh.
I didnt have a aftermarket V Force setup to test but I believe it would flow more yet in the ÔÇ£Big CT
I then tested both intakes with out the reed blocks installed. This number compared to the best flow number with reed blocks installed will tell us how much each reed setup restricts flow.
Since booth inlet and exit sizes were the same it didnÔÇÖt surprise me that they flowed almost the same.
Bears 93.9 cfm
BIG 95.0 cfm
Conclusions
Bears CT Black with the 2 petal CF reeds setup is better the the Std CT most of us run.. even if you run the optional CF reeds with the finger springs removed. Also I cant see anywhere you can improve this setup.. IMHO its maxed out as tested.
But while the ÔÇ£BigÔÇØ CT Black flows slightly less out of the box it flows substantially more by simply removing the ÔÇ£fingerÔÇØ springs and reed stops.
I think it has still more untapped potential using a better after market reed setup that you cant fit in the smaller Black.
As you can see from the ÔÇ£No reed blockÔÇØ test the smaller manifold is held back by the smaller reed block area available and the smaller area around the reeds that seems to restrict the flow.
In my opinion if your motor can benefit from more intake flow the ÔÇ£BigÔÇØ is the better manifold system. Now how big a motor you need to benefit from the increased flow will have to be proven at the track.... I can only show you which one flows more air.
Special thanks to Bear who graciously sent me his manifold for testing!!
