Ehughes

I pulled this off my 94' from Puerto Rico.
What do you think of the layout?

https://www.rx7club.com/forum/attach...postid=2155944

I am not crazy about the dump of the Wastegate into the open.

Carl Byck

The wastegate runner is going the wrong direction, you can always plumb the WG back into the DP farther down. It is undivided(not optimum) and the runners are shorter than optimal, all in all about what many run, but far from optimum.

Ehughes

Thanks. Anyone else have comments?

crispeed

That looks like a SFP manifold!

Ehughes

What is "SFP"?

in2twins

South Florida Performance.

carx7

iTrader: (31)

Typical... but far from optimal as Carl said.

-Chris

MeLoco

Is the exhuast side diveded on the turbo?,if not, that may be why it's not a divided manifold though it could still benifit from it to some degree, I don't see how the wastgate runner is going in the wrong direction though, you would need to see in the manifold to see how it mates up with the runners, ie. if it is angled slightly downward it wouldn't be bad, you could also cut the wastegate flange off turn it clockwise 90' and you would be good to go for rerouting it back in the DP.

Ehughes

http://cgi.ebay.com/ws/eBayISAPI.dll...tem=2433072629

RETed

Funny, a few years ago I ragged on the A-Spec Tuning FD kit and it had a worse design that the SFP unit, and I got jumped on for bagging on their stuff.&nbsp Now, it looks like consumers are getting a lot more knowledgable about turbo exhaust manifold design.

The SFP one is not that bad, IMO.&nbsp We're going to try and run a similar design for a Zenki 13BT soon with a Garrett GT-35xx.&nbsp The reason for running the wastegate discharge from the base of the turbine inlet flange is due to a high pressure area for the exhaust gases right before going into the turbine - see Corky Bell "Maximum Boost" for pics on this set-up.&nbsp Sure, it's not optimal in exhaust gas vector direction, but running an HKS GT wastegate should more than handle any exhaust exiting responsibilities. The one bad design flaw of the SFP unit is the fact it's using unbalanced runners to the turbo.

That other eBay SS shiny unit I don't like at all.&nbsp Unbalanced runners with non-optimum placement of wastegate discharge makes for an inefficient design.

Zero R

iTrader: (1)

True, but you sometimes you don't come off right either, and I think most people on here only know just enough to think they know ehough wouldn't you agree.

-Sean

RETed

Sure, but when Corky Bell supports it in his book, I would think that's pretty good evidence that you're on the right track.

Most of this turbo exhaust manifold design stuff is common sense - think like a gas molecule.&nbsp Corky Bell does a good job in "Maximum Boost" to go into depth on what is good and what is bad in terms of turbo exhaust manifolds...


-Ted

Zero R

iTrader: (1)

I would agree,and that's why when I got the time to redesign the manifold I did, keep in mind the first time I asked someone else to handle it for me and that mistake wont happen again,but I do get so tired of hearing "Corkey Bell says" don't you?

crispeed

The SFP might look un-balance from the outside but from the inside both sides are very closely collected.

Ehughes

Your right. I took a line and measured the runners on my manifold (from the pic above). They are pretty damn close in length. Visually, it is deceiving.

RETed

I dunno...
Not many times I've heard people say they get tired of the Bible or the dictionary...


-Ted

Maxthe7man

Corky bell , I might add , has had plenty of fuckups of his own, and is not the be all and end all of trubo installation, while I do like his book, and some of the theory in it, its not possible sometimes to incorporate all of it perfectly into a design.. When he shows a "bad" or "poor" installation, he does not show the same car with his alternative installed, its ok to posture from the sidelines, its a whole different story to be the one holding the tig torch...
Ask corky about turbocharging NSX's...He just about lost is *** over that kit, maybe he forgot to read his own book...Max

RETed

Sure, I understand where you're coming from, but his manifold design section is pretty damn good.&nbsp I don't see anyone offering alternatives out there?&nbsp You can criticize Corky Bell and his book all you want, but I haven't come across anything better that's in print...

I don't see anything wrong with what he talks about when building a turbo exhaust manifold.&nbsp Might I ask where you have a beef with Corky Bell on this particular subject?


-Ted

boostedrotor

i don't think that is a sfp manifold, of all the ones i have seen none have the waste gate dump there......mine also says sfp and so do all my friends that have the sfp manifold...

crispeed

A lot of the early ones did not have the SFP badge on it and also had the pipe for the wastegate in that position.

Maxthe7man

Find a good technical library in a trade school, there are more books out there than Corky's , I have a whole range of books written on the subject of manifold building and tuning, Hugh Macinnes, smokey Yunik, Mickey Thompson, Dave Vizard, have all touched on the subject of manifold design, especially tuned length runners for both n/a and forced induction, they actually give you the calculations, and the workable physics behind it, not just,"it works better" or " we saw a measurable difference", gee thanks corky, I feel so enlightened...
His theory though sound, oops or his assumption, shows up in his book, but doesn't seem to follow what he sells in real life, I bought his book, and was actually a little dissapointed in the fact that it was more shear opinion on most of the subjects, while he fails to show the theory in depth behind it, and thats what makes Hugh Macinnes's book especially so much better, even though its quite dated, its far better book for actual turbo application.. Bell is the Martha Stewart of the turbo world, he just regurgitates what everyone already knows, but was just selling no more than common sense in the book.. Can you size a turbo from Maximum boost, not really, from Hugh Maciness, yeah probably...
Corky bell needs to write a postscript in Maximum boost, that reads. "all the project cars used for examples in this book were finished by someone else that actually knew what they were doing, or sold and parted out because they never worked right, I think that Jag is still for sale, it was in Hemmings for years...
There are lots of people out there in this world like Corky that talk a good game, but can't play it in real life, most of them crown themselves as experts and then write books unfortunatly...Max

IGY

I have an early one that looks exactly like that. A friend of mine got a later one and the wastegate pipe was on the outside(does not work on a right hand drive car) and had to be changed. The pic is very misleading. As far as runner length goes they are very close to the same. I swear by this manifold, very stout.

RETed

I have the Hugh MacInnes book, and it's really outdated.&nbsp I haven't seen any of the other authors' writings, but I have a feeling they are all NA applications mostly?&nbsp If so, it's almost not applicable.&nbsp I do not recognize David Vizard's name though - I did a quick search on his name on Amazon, and it looked mostly like NA applications.

Have you seen the SAE papers on the (turbo) rotary engine?&nbsp I'll take this reference over any published media list, including Corky Bell's.

I think Corky Bell's "Maximum Boost" is a bit too simplified for your mind.&nbsp I think it's a great book for the beginner, and I think it was written at that level.&nbsp Hell, even the Hugh MacInnes "Turbocharging" was written at a much higher level.&nbsp I'd like to hear any options for the newbie who'd like to read up on turbocharging?




I agree the publication was too biased towards his company, BEGI.


I learned how to size turbos from "Turbocharging", although it uses the old standards of airflow for computations.&nbsp Other than that, the only other thing that was interesting was the water injection chart.


See above - I agree that it's titled towards his products; I never bought the book to read up on his VNT crap.&nbsp I did buy it because it was a publication on modern turbocharging theory.&nbsp There are very few publications available in the local bookstore on such subjects.&nbsp I had no problem following Corky Bell's explanation on turbo sizing...


I think it's a waste of time trying to argue the merits of Corky Bell's "Maximum Boost".&nbsp I still find it interesting, although the $30+ cost is rather high.&nbsp I still recommend this a read for most people trying to read up on turbocharging.&nbsp Very few of them can access special trade publications and materials that are limited.&nbsp I'm still looking for alternatives to "Maximum Boost", but I haven't found any suitable suggestions...I don't think applications on NA header an and exhuast tuning is especially useful in this case.
If nothing exiciting comes out of this thread, my additions end here.


-Ted

little rotor

Ted, you mentioned some SAE papers on turboed rotaries. Do you have their numbers? Thanks.

Maxthe7man

The only difference between a boosted engine and non boosted engine is the charge density, by all means n/a tuning applies, if it were not so, would the equal length turbo header not be so important? Remember the advantages of equal length were first found on n/a engines, and that tuning the exhaust pulses had merit.
I have a series of books called Super power, that are better than bells book for introduction to forced induction, as a plus they cover supercharging, intake design, efi theory, and nitrous application, its an older set, but you still see them around, far better read than Maximum boost..
I think what sets Macinnes apart from bell is the definite anwers, when you read macinnes, he starts sentences with "here is", "this is how"," THis is why", where as bell writes "Generally" "sometimes","it maybe"..etc etc...
When I put my system together, I can truthfully say, when I was stuck or unsure of something, I picked up maximum boost, but more often than not, I found for definitive answer, I ended up looking and finding it in"turbochargers", being that I have been through the turbocharger from scratch mill, I can say that for those interested in doing their own system , turbochargers is far better book...Max