12cm housing question

[stunt2]

I'm interested if the 7 blade HX35 can reach its maximum capability with 12cm TS housing ? is there any chance of choke on 2.3 engine with S2 cams ?

thanks

 

[Marchev]

Yes, hx35 can reach its full potential in the stock t3 housing. Its also recommended that you use a non divided t3 manifold for better results. Check out the holset sticky thread under the turbo section on the forum.

 

[stunt2]

can't get why non divided manifold can be better on divided hotside

 

[LandSpeed-DSM]

Yes, hx35 can reach its full potential in the stock t3 housing. Its also recommended that you use a non divided t3 manifold for better results. Check out the holset sticky thread under the turbo section on the forum.

False, you not only are failing to take advantage of the VE gains associated with a divided housing by mounting it on an non divided manifold, you will be hurting spool and total flow from the turbulence of hitting the divider.

It's safe to say that in general, almost all available combinations of parts that mate any flavor of HX35 on a 100mm crank 2.3L 4G63 engine will make for a rowdy street ride.

The specific combination of VE components (cam/manifolds, etc) is going to determine where you will wind up on the compressor map at a given PR/RPM point.

The 12cm^2 Divided T3 housing is the best option for an HX35 turbine and will allow you to max out any of the available compressor wheels. It's just not the most affordable to do properly.

 

[Marchev]

Im just stating whats on the FAQ holset turbo thread. People put a lot of effort to create that thread so I always used it as a secure source of information. On it, it clearly states to use a non divided manifold...

http://www.dsmtuners.com/forums/turbo-system-tech/362444-holset-turbos-faq.html

 

[stunt2]

LandSpeed-DSM

the reason I'm asking is that I've got the turbo mentioned above but with 14cm housing and I'm wondering - use it as is, or spend money for 12cm housing, if 14cm one won't give me anything but the increased spool time and transient response

 

[LandSpeed-DSM]

Im just stating whats on the FAQ holset turbo thread. People put a lot of effort to create that thread so I always used it as a secure source of information. On it, it clearly states to use a non divided manifold...

http://www.dsmtuners.com/forums/turbo-system-tech/362444-holset-turbos-faq.html

There is also a ton of bad information on this site, beyond that there is the reader's own interpretation.

The only thing I can find on that page about this is:

"This mated to a NON-divided runner manifold has produced a 132mph trap speed with a full weight 1g AWD. This is about 600whp. So the flow is there with the stock housing if you use a non-divided manifold."

This statement is not telling or recommending that readers to use a non-divided manifold with a divided housing. This is clumsily worded, but it is just providing the singular data point that this particular turbo was mounted on a setup with an Open T3 manifold and trapped 132mph.

Mass flow is still limited to what the nozzle area and wheel will permit.. the big flaw is that you are allowing exhaust pulses and valve events to interfere and interrupt each other, requiring smaller overlap (cam timing) to fight charge contamination in other cylinders, slowing pulse velocity and choking prematurely because the gasses then have to try and re-organize themselves around the divider effectively making the available cross-section smaller.

This decreases turbine efficiency, which hurts the breathing ability of everything upstream, in gasoline vehicles it will make them more knock prone among other effects..

In short: You do want to use a divided manifold with a divided housing. You can get away with a non divided manifold.. but then you would be better off with swapping in a non divided housing.

 

[stunt2]

let's not talk about manifold guys I do know what manifold to go with, my question is completely different

 

[LandSpeed-DSM]

It's safe to say that in general, almost all available combinations of parts that mate any flavor of HX35 on a 100mm crank 2.3L 4G63 engine will make for a rowdy street ride.

The specific combination of VE components (cam/manifolds, etc) is going to determine where you will wind up on the compressor map at a given PR/RPM point.

The 12cm^2 Divided T3 housing is the best option for an HX35 turbine and will allow you to max out any of the available compressor wheels. It's just not the most affordable to do properly.

let's not talk about manifold guys I do know what manifold to go with, my question is completely different

 

[bastarddsm]

From personal experience, a true divided setup will flow less than an open manifold on the same housing.