FULL RACE T4 bottom mount Twin Scroll
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I know this manifold has been just released, but what would be the benefit of running this one compared to a topmount twinscroll? Spool time? Max HP? Size of DP...etc.?
Originally Posted by TheShodan
Interesting design. Like back in 99.
would one of these be better for a 30r(with twin scroll) than say the 30r with a tial housing
Its not exactly a new design by any means... I thought the same thing, but if it works, why fix it ---
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Originally Posted by EARLdaSQUIRREL
care to explain the comment
would one of these be better for a 30r(with twin scroll) than say the 30r with a tial housing
Originally Posted by boostedcivicsir
that manifold can also facilitate a 372/42r into a crx. and still have the benefit of the twin scroll.
Originally Posted by EARLdaSQUIRREL
care to explain the comment
would one of these be better for a 30r(with twin scroll) than say the 30r with a tial housing
can you explain the differences than? between twin scroll and divided housing, i feel this thread would be a great place for it to be explained
Twin scroll is NOT simply a divided housing....
It derives its name from the geometry of the exhaust gas inlet into the turbine. Two different-sized scrolls are generally used, a primary and a secondary. The primary is open for low-speed operation, and both for high-speed use. This creates the ability of the Twin scroll setup to be a small A/R housing at low speeds and a large A/R at higher speeds.
Divided is simply a split housing that you can pair runners to in order to aid spool.
Totally different
It derives its name from the geometry of the exhaust gas inlet into the turbine. Two different-sized scrolls are generally used, a primary and a secondary. The primary is open for low-speed operation, and both for high-speed use. This creates the ability of the Twin scroll setup to be a small A/R housing at low speeds and a large A/R at higher speeds.
Divided is simply a split housing that you can pair runners to in order to aid spool.
Totally different
Twin scroll refers to the entire system - half the cylinders pumping into one half of the turbine. Divided refers to the housing & flange. Kinda like saying 'tranny' and 'drivetrain', one is part of the other.
The benifits of a twin-scroll setup is listed in many threads & web pages - its rather simple. Due to less volume (half in this case) for each exhaust pulse fill, you reach peak exhaust pressure faster to spool the turbo. You also prevent one exhaust pulse (opening valve) from interfering with an overlap event (closing valve), so less issues with reversion as well as better scavenging. AND since you can size the housing & runners a bit larger, you end up with better overall flow.
So you get:
*faster spool
*more power
*better scavenging
*less reversion
Its obvious why this is seen on V-motors and I-6's - its much easier to divide the cylinder pulses properly.
The benifits of a twin-scroll setup is listed in many threads & web pages - its rather simple. Due to less volume (half in this case) for each exhaust pulse fill, you reach peak exhaust pressure faster to spool the turbo. You also prevent one exhaust pulse (opening valve) from interfering with an overlap event (closing valve), so less issues with reversion as well as better scavenging. AND since you can size the housing & runners a bit larger, you end up with better overall flow.
So you get:
*faster spool
*more power
*better scavenging
*less reversion
Its obvious why this is seen on V-motors and I-6's - its much easier to divide the cylinder pulses properly.
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Originally Posted by leach
geoff says there 3 to 4 weeks out but my name is on one
ok new to this but is there a difference between it being bottom compared to top im tryin to decide on what manifold i want and im using h1e holset turbo
I would imagine the bottom mount will spool the turbo faster vs the topmount mainly due to the runners being much shorter, it is probably lighter too. I wonder if it shares the same collector length/design as the topmount or if that area has been revised as well. I am very interested in this pending the price, a topmount is just too baller for me
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