Hey guys, I am still tring to find a solution to the stock plenum design where it causes our #5 and #6 cylinders to run slightly leaner then the others. I dont want a aftermarket plenum if it means replacing or removing the stock strut bar with a fugly looking one. Are there any nice looking strut bars that are as stiff or slightly more so then the stock one?

Has anyone considered modifiing their injectors in the #5 and #6 cylinder to perhapes deliver maybe 5% more fuel into the cylinders to compensate for the extra air.

I recently found a pic of someone w/o their plenum and noticed that there are like half domes over each cylinder's port. Is it possible to machine that dome slightly smaller so more air can enter the #1 - #4 cylinders and maybe even out the amount of air entering all 6 cylinders so the FI guys can get a truer WB reading and get the most out of our motors?

I dont know diddly so if it sounds like I just pulled something out fo my azz, please excuse me and set me straight. TY!

 

I ordered the crawford V5 plenum to deal with this problem as i will be going TT soon enough. I believe these Jic strut tower bars will fit over the crawford plenum.....I may be wrong however i think ive seen a pic of one on a car with the crawford!

 

squilll.....can you confirm that bar will fit? If so..I will order a V5 plenum.

Enron, with a stand alone...it would be a snap to add IPW to injectors 5 and 6. But the eManage wont let us do that.

Now...I bet someone with some electronical savy(not me) can develop a way to tap the #5 #6 injectors and add a bit more IPW to those wires, AFTER the eManage has done its across the board enrichement. You would need injector drivers in this special "black box"...I have no idea how to design this....but...
in theory, it does seem too difficult. Any suggestions?

 

Looks like i ve lost my mind and am seeing things again (my shrink warned me this would happen if i stopped all the meds )

https://my350z.com/forum/showthread....t=jic+crawford
https://my350z.com/forum/showthread....t=jic+crawford

oops looks like it wont fit.

 

Nope....no bars fit with the Crawford plenum, except for Crawfords

--wes

 

How much PSI is the V3 Kinetix plenum rated for?

 

Why not order the Crawford V5 and get the the Crawford strut bar as well? I did and I can't tell a difference in handling. The additional cost is minimal and is a lot easier than messing with the injectors like you mentioned...

By the way, I reccomend the polished V5 plenum but I am a little biased

 

GQ, That's a very difficult task. The emanage does a decent job of doing that. I think the best way to do it would be to get Greddy to add a function to the emanage software that would allow you to add more PW per channel on the injector harness. I can think of a lot fo cool stuff they could do with the emanage just in the form of software updates. For example, can you say studder box?

 

I am thinking at least for me personaly I will go ahead and get the (V4 now) Kinetix plenum, because as soon as any problem is found with their products, they automaticly create a new version.

Just on the basis of their customer service track record so far, I feel safe getting the Kinetix plenum with their HF cat in the special on their website.

Even though I will eventually need the plenum to be able to handle at least 8psi.

I believe their plenums are supposed to operate upwards of 9psi, and I assume this can only get better.

 

hey jax if you get the kinetix i would love to see how it looks in person as i have been considering it for some time, which side of town do you live on, im in arlington so maybe we could meet up if you get it.

 

The Kinetix will handle 9-10 lbs of FI air?

 

I'll let you know in about 2 days! (well, at least 8 psi)

 

CaneZMD, did you ever figure out where to get the boost "signal" from with the Kinetix plenum?

--Steve

 

You a better off turning you system into a return style fuel system. The design of the stock plenum is to compinsate for less fuel getting to the front 2 cylinders cause of the dead headed "Heated" fuel going to cylinders #1 and 2...So actually the front 2 cylinders have been noted to run the leanest or most prone to detonation, believe it or not...We had this discussion with Dave from APS over dinner during the ATCO weekend and he does not suggest exceeding 450 Crank HP on a returnless fuel system and stock rods..They have bent a stock rod on their car during development...

 

I know plastic is strong...and stuff. But I would never trust a plastic plennum with significant amounts of FI. With enough pressure, I think the plastic would stretch?? Maybe....

 

I completely agree. It looks like many N/A guys are having issues with plastic. I can only imagine what would happen if an F/I Z used plastic.

 

Interesting. What else did they mention?

 

Zimbo, I used the vacuum hose coming off the back of the plenum, just behind the throttle body.

About the idea of using plastic, It depends what kind of plastic your talking about. The real question, about NA vs FI with the plenum, is how much vacuum is placed in an NA engine compared to the amount of boost in the FI application. If there is say 12 "pounds of vacuum" at idle in NA, than 8 psi of boost isn't that bad. But I haven't found anyone who knows how much vac there is. I guess I'll find out tomorrow when my gauge gets hooked up.

 

There is 10psi of vacuum at idle.

Regardless, after the countless stories of cracked plastic plenums, I'm sorry, but I would never put this on my TT car....just my opinion.

I'm going with the V5 Crawford....even though I have to ditch the factory bar.

 

I disagree 100% with this. It's been well documented on the boards that cylinders 5-6 are running leaner. Nearly every engine blow-up with the Z has been in cylinder 5 or 6..or both...the cylinders closes to the firewall.

The fuel in the rail is at a relatively constant temp...since its returnless, and if the temp increases slightly...it is still not an issue in terms of detonation. excess vapors are venting back to the manifold....and the risk of detonation becuase of fuel temp would not be any different between the different cylinders.

The plenum was design to allow a steep sloping of the hood. No question, it was not designed for high performance applications. Take a look at any Mits/M3/etc..etc..not just supercars, but even normal sports cars...they have very intricately design plenums, that insure proper and even airflow to all cylinders.