OK, so as we all have seen Full Race has released the newly developed bottom mount manifold for the B-series peeps.

I have a few questions and would like to open up a discussion on these two manifold designs. I would really love to hear from Geoff and I would like to see some test results when they become available.

Questions that I have....

Could I expect to see better response with this new manifold design?

Are the primary lengths shorter than the top mount design?

Same diameter primaries in both manifolds?

Collector design in the top mount seems to be designed better for flow.... any truth to this?

Since we all know that exhaust manifold pressure plays a big role in turbo response (mostly turbine housing A/R related) does this new manifold flow well and can one expect to see an increase or decrease in pressures?

How close to equal length is this new design?

Please keep the "top mount is better" or "ccfab is better" comments to a minimum. I would really like to keep this discussion professional and technical.

Thanks.

 

its been a while since i was actively posting on here, but we have experimented and learned a LOT in the past few years. Following the tradition that Full-Race strives to maintain as the most cutting edge state-of-the-art turbokit and manifold mfg, optimizing turbocharger response and powerband has been our primary focus over the past 2 years. The lesson i have learned loud and clear is that if its not twinscroll dual wastegate, its not working as well as it could be. We have refined twinscroll so far that we can consistently run huge turbos with massive turbine housings, allowing the bigass turbo to flow huge numbers and still spool MUCH earlier and respond MUCH faster than any traditional singlescroll "open volute" turbocharger. This is a result of our perfect collectors, consistent runner and collector geometry, and impeccable construction/welding/fabrication. I believe this latest twinscroll bottom mount manifold design is a step fowards from our twinscroll top mount, which is long considered the best manifold for street class b series turbo hondas. anyone who thinks open scroll works better, doesnt understand what theyre talking about.

The twinscroll bottom mount manifold we had on display at etown was a pre-production prototype and it will receive a few more small revisions before going on sale. testing will take place as soon as the design is finished, and with a few differnet sized turbos. to answer your questions without giving all the data out on a public forum for the lemmings to eat up ill say this -

i consider our topmount manifold to have the "perfect" runner geometry for a high power singlescroll turbocharger, and it lends itself perfectly to twinscroll dual wastegate configs. Our twinscroll dual wastegate design obviously works very well, but i felt the runners were slightly longer and had a higher pressure drop than optimum for these turbos when setup perfectly.

this new twinscroll bottom mount manifold takes a step forwards in terms of improved response, better CG, shorter downpipe, shorter charge piping, reduced pressure drop, reduced wall friction, shorter oil return, it fits an EF with 42R and 2 WGs, it fits an EG better and with more room, same with EK and DC... until testing is done its hard to say which will reign supreme. tony proved the superiority of the top mount design this weekend and i know of a couple more guys who went reallll fast and commented how well the twinscroll top mounts worked for them.



Modified by Full-Race Geoff at 9:51 AM 10/14/2008

 

Thanks for the details Geoff. Seems like everything that I assumed would be better actually is. I know that the topmount is proven, but I felt that this design would be even better. It was only a matter of time. I'm sure the next design just may be the front mount.... right?

When you say less wall friction I would have assumed that the topmount would have less. Is that only due to there being less overall bends and not having to make that 'U' shaped topmount turn? (the turn that takes place at the lower half of the manifold)

Reduced pressure drop.... where is this measured? Inside or outside of a bend or in the collector?

I put it in the drag forum because that is where the racers are. The ones who mostly use the manifold to it's full potential. Plus, there tends to be better tech and less "youngsters" that add wise *** comments. lol

Thank you for your time and response.

 

 

Looks like it would also eliminate a lot of heat on the radiator from the downpipe. For those who arent running it through the hood. I was hoping that it was going to be cheaper than the top mount (solely from less material) but from what Geoff has said I can understand the price from the R&D thats been put into it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Full-Race Geoff &raquo;</TD></TR><TR><TD CLASS="quote">but i felt the runners were slightly longer and had a higher pressure drop than optimum for these turbos when setup perfectly.</TD></TR></TABLE>

...says the man who's company is pimping the WRC dual-scroll kit on the front page. THAT 'manifold' has runners longer than my ... well, far longer than any Honda topmount - despite the engine's extra displacement.

Yes, I'm joking not flaming. I appreciate that some companies are interested in advancing the 'scene' as other call it, rather than ONLY make money off of it.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tepid1 &raquo;</TD></TR><TR><TD CLASS="quote">When you say less wall friction I would have assumed that the topmount would have less. Is that only due to there being less overall bends and not having to make that 'U' shaped topmount turn? (the turn that takes place at the lower half of the manifold)

Reduced pressure drop.... where is this measured? Inside or outside of a bend or in the collector?</TD></TR></TABLE>

The unscientific way of finding that out is guessing based on runner length, which can be very inaccurate. I think it was something like 3-4' of tubing has less restriction than a 90* bend. For that matter, three 45* bends have the same pressure drop as a single 90*. Given both types seem to have roughly the same amount of bends, it generally would come down to runner length.

If F-R did measure pressure drop, it would have been between the collector base to right after a exhaust port. Less pressure drop means you need less backpressure at the exhaust port for the same turbine speed. We all know what that helps with...


btw just for visual compairison, the topmount style:

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HiProfile &raquo;</TD></TR><TR><TD CLASS="quote">...says the man who's company is pimping the WRC dual-scroll kit on the front page.</TD></TR></TABLE>

I don't normally double-post, let alone quote myself...(who better to do so to? ), but I have a kinda side-bar question:

Given the <U>Full-Race WRC kit</U>'s 4-2-1 design, have you ever tried that with a Honda topmount? Something tells me it would be excellent for the street (cheaper, better spool than undivided). As I mentioned, fluid dymanics tells us bends are a big killer of flow (vs anything else), and a 4-2-1 design on a Honda would require 1/3 less elbows than those two manifolds, as well as less piping. Given the pulses are well divided, I would assume merging hald the runners RATHER FAR before the turbo would end up better due to less bends and piping?

 

my experience going from a t3t4 sc61 turbo ramhorn to a full race top mount bw s372r you can barely notice a diffrence in spool up driving it on the streets. sounds like a jet ahaha here are some pictures

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by timg &raquo;</TD></TR><TR><TD CLASS="quote">when are you coming out with a divided setup for the S2000? </TD></TR></TABLE>

we have a hardcore s2000 testbed here, and have been working on the development of a very impressive and affordable turbokit. The system will cost less than our current kits, make more power, spool faster and weigh less. Unfortunately the turbo will not be for sale to the public until december. Once it is available, we will not disappoint.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1Quikgsr &raquo;</TD></TR><TR><TD CLASS="quote">my experience going from a t3t4 sc61 turbo ramhorn to a full race top mount bw s372r you can barely notice a diffrence in spool up driving it on the streets. </TD></TR></TABLE>

thanks for the comment, glad to know you can spool a MASSIVE S372 turbo like its a little 35R wait until you see what we have in store... all in due time

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mikey3000 &raquo;</TD></TR><TR><TD CLASS="quote">would there be a possibility of one of these new bottom mounts being available for the H22? even if it was a 1-off just for meeeeeeee. </TD></TR></TABLE>

no possibility of doing any more H series, sorry for the bad news

 

I have read this thread and it should remain locked.

It will be searchable in the database, and users having questions can ask them in followup, independent threads.

Thread has been redacted after we decided that there was evidence that it's basically a thinly veiled marketing device.

However, we do not think that any particular prejudice should be applied to the developer because it's a very common occurrence that simply happened to attract enough attention for it to generate reports to moderators and staff.

People who want to ask more about this can just start their own independent threads and moderators will monitor them.