JW/Pro Jay intake manifolds
 

ive been thinking of converting my street ported s4 13bt to use the jw intake manifold along with some sort of multiblade t/b.im sure im going to lose a significant amount of bottom and midrange power, im ok with that as long as it will shift my powerband up towards the upper RPM band. with the conversion ive thought about a few thing...

1.)Does the JW intake have some sort of plenum, or does it just have a single hole for each runner?
a.)if not what is the best method to get a good vacuum signal for a MAP sensor?( vacuum spider with a leg going to each runner maybe?) with the stock intake manifold i pull about 15" of vacuum at 1300rpm (i havent played with my idle yet).

2.) How high up will these intake manifolds move my powerband? (i plan on going with a s475 on a street ported s4). of course i know there is no definitive answer to this question but im just curious what results others have seen.

3.) do people still use injectors staged?
a.)if yes do people keep the primaries in the center iron?

4.)what has more impact on powerband placement, intake manifold or port timing?

5.)the throttle body im looking at has provisions for 8 injectors,i want to use 4 or 6,does anyone make blanks/inserts?

6.)what are the differences between the JW and the ProJay manifolds?

thanx alot party people! :)

1 No, it's just four holes, one for each port. Just run two lines to a vacuum log, one from each primary port.

2 You won't loose as much bottom end as you would think, the off idle drivability will suffer the most.

3 Yes they do, i idle on 4-1600cc and then stage in 8-1600cc at 12psi.
a Yes, i have a set in the iron.

4 They go hand in hand. To really benefit from the shorter runners you need a pretty aggressive port timing (more than a street port)

5 Yes, i would look at the RXPARTS.COM intake and throttle body, they are VERY nice pieces. You don't have hood clearance issues, they have provisions for the 7th bolt (JW and Jay Tech don't), and they sell blanking plugs so you can run just about any combo you want to.

6 Personal preference and availability.

With the JW intake, I don't believe you could plug 4 injectors because of the intake runner layout. It can probably be done by blocking the #2 & #3 injectors of either side of the TB. Hope I'm making sense with my explaination.

Buy a RXPARTS intake... it will save you time, stress and you have the ability to block off an entire side of injectors with a simple block off plate.

i'll be running a rxparts.com intake and TB on my half bridge rew motor with a s475.

as allen and aaron stated, its your best option for driveability due to its progressive throttle linkage and has avalible block offs for one bank of injectors allowing you to run 2 in the center oron, and then stage the 4 secondaries in the tb.

e mail rxpartsonline@gmail.com for more info.

the manifolds are avalible for FD and cosmo engines at this time. no series 4 right now, but thier TB's will work on a JW or jaytech lower.

5 - I've seen people using mustang injectors as "blanks". Meaning they are installed on the TB, but not pluged in to the ECU.

6 - They are very similar. The most noticeable difference is how wide the area around the center/primary ports is. The JW manifold takes much more space, vs the jay tech. Its hard to explain, but picture it like this, if you are looking at both intakes from the top, they would look like this:

JW - U

Jay Tech - W

The jay tech provides more space, in the area were most conventional turbo sits. Does that makes sense?

Fellas,

Whats the price of the RXParts TB?

I am running one of the old school 4 injectors, and wouldn't mind going over to one of those!!

what is the "7th" bolt?

since RXPARTS doesnt make a manifold for my S4( and i cant port a manifold to match,since the intake mani. ports are too large (not a fan of epoxy)), do you think one of these would help me with the hood clearance problem you were talking about

http://www.6061.com/elbows.htm

im sure enzo is probably the best one to answer since hes the only one in here with a 2nd gen. now if i did go with this elbow and a massive 90 or 100mm t/b i picture having absolutly terrible off idle and part throttle performance (not that it matters).anyone have any experience with a large single blade t/b, or does everyone do multiblade t/b's for a reason!

thanx alot!

im an idiot, if i did that id have no provisions for fuel injectors lmao!

:(

Manifolds:
https://www.rx7club.com/picture.php?...pictureid=7521

Installed with mock up intercooler pipes:
https://www.rx7club.com/picture.php?...pictureid=7523

o crap i didnt know u had a 2nd gen aswell lol

are you still using a s4 or s5 or did you go to the re? what t/b intake are you using?

I'm currently using a jaytech manifold and e&j t/b on my extended port Tii motor.Originally i had a modified factory manifold.I've found that the engine does want to rev alot harder with the 4 barrell intake,as my engine is race only i couldn't comment on driveability but it sure is responsive!:)

Its a S5, with a JW intake and a 4 injector TB that I purchased from a PR tuner/mechanic (long time ago). The car needs a tune, (no boosting) but driving around the city seems fine.

Is there any benefit going with this pro jay intake and the big 8 injector carbeurator, over say an xcessive lim, with a port matched upper, what are the real pros/ cons.

^^
The shorter runners give you a broader powerband. (so a little birdie told me ;) )
BTW..the pvc intercooler piping is top notch! lol...

Thanks man :suspect::lol:

I understand the runners are shorter but the time spent fuel with air is actually more as the injectors are set quite far away, atleast thats what Pro Jay has told me. I was under the assumption the runner length biggest impact is played after the fuel has been mixed, still learning though. I am also wondering, similar to the first post in this thread about the number of injejectors that can be used, and also can the PFC run with this setup.

Ernie, thanks for the input but is there any other information you can shed regarding the cons moreso of this setup, or is it all good.

As far as the injectors, it all depends on the TB. You can run your primary & secondary injectors off the TB location, or you can run your primary injectors from the OEM location, and as many as you want on the TB as the secondaries.

There is a TB with 4 injectors and there is one with 8 injectors. The possibilities are endless...

As far as running four injectors in the tb setup , are the stock locations simply blocked off, and also, can the pfc run with this setup?

Yes sir.


Good question.

ANCIENT THREAD! But I have to ask...

Where do you figure on when you say "bottom end"? Just curious.

I'm running a bit different setup than most (S4 TII block, half-bridged but N/A) and I found that the TII intake manifold just plain sucks for airflow. Like, I somewhat ineptly epoxied and modified a S4 N/A intake manifold to fit and it flows better basically everywhere. 2000, 4000, 6000, 8000, everywhere. So it's not really hard to be better than the TII manifold, I think.

I also experimented with an open plenum upper for the TII manifold and found that off-idle response and drivability suffered greatly. (This was while I was still streetported) Like, I had to pull 10-20% fuel out in some places... so I think that a progressive throttle is mandatory for decent drivability, if you care about that sort of thing.

Aug 2010 Update.....


The Pro-Jay intake manifold and throttle bodies are hands down the best in the industry. ..They are the clean castings to begin with and the final machined parts are excellent.

On the Semi-manifolds, a home made version or a jw that is machined for a semi use is one way to lean out one rotor..I have seen irregular flow patterns from home made semi-manifolds...The Pro-jay manifolds have equal "volumetric" runners..

they are the only ones with a 1490cfm throttle bodies and the thick wall turbo -hats..this way you wont have to weld the crap out of the top section of the hat.


http://i30.tinypic.com/2pzg1ab.jpg
http://i31.tinypic.com/11rqgeh.jpg
http://i32.tinypic.com/1z15tmp.jpg
http://www.grs-motorsports.com/notic...jay/foro/2.jpg
http://www.grs-motorsports.com/notic...jay/foro/5.jpg
http://www.grs-motorsports.com/notic...jay/foro/7.jpg
http://www.grs-motorsports.com/notic...jay/foro/9.jpg
http://www.grs-motorsports.com/notic...ay/foro/12.jpg
http://www.grs-motorsports.com/notic...ay/foro/14.jpg
http://www.grs-motorsports.com/notic...ay/foro/15.jpg
http://www.grs-motorsports.com/notic...ay/foro/17.jpg
http://www.grs-motorsports.com/notic...ay/foro/18.jpg

From idle to say 2000-2500 RPM

Anybody have a JW intake they want to get rid off?

Rotaryb where do u get your info from?

I could be wrong but someone told me he was Goopy.