IMO - the reason Kinetix's plenums kept cracking is because they were trying to cut costs by using a material that might be strong enough, but was cheap enough to justify the price they were charging... now they figured they can't skimp on materials, so we're going to have a product that is well worth the money, but hopefully doesn't bankrupt Kinetix...

 

I am just wondering how they reinforced the inside without the two mounting bolts on top...

 

I doubt thats true. resin for something like this is cheap; and they are all pretty similair in price, within a few bucks. now maybe they did try to save, but if so, its in the order of 5$ or less. Id bet it had more to do with the material having either better (worse) heat transfer; or perhaps stronger in a different way, could be strong to impact but not flexing. maybge they went with something a bit more flexable, you know, bent but dont break.

 

That's what I am guessing, bend (flex) but don't break... since the two mounting bolts are not needed anymore...

 

Kinetix is a great company with great customer service and great people who work there. This plastic plenum is a great idea, its cheaper, stays cooler, you get to keep your stut tower bar, use your engine cover with no modification, imo looks better then crawfords, and I also commend them for bringing a new and different product to the 350Z community. However, the CHANCE that the thign MIGHT crack and cause problems does not justify all of the above for me anymore. I don't know why I tried the V3 in the first place, should have justwent the 110% reliable way. If you can avoid headachs, and you damn well know there could be a problem, why put yourself in that situation?

No more "chances" for me, do it right the first time.

Again, great company and great idea on the product. Might even be perfected one day, but I just would not take the chance.

 

From what I understand, the V4 has the center posts integrated into the top of the plenum (similar to the stock plenum). I think that that if they keep with their original design there will only be the 2 center posts.

However it may be better if they integrated all 6 posts, it may serve to make the unit FAR more stable and remove all flexing completely.

I am curious though how the plenum will be mounted with those posts. The previous plenums included 4 screws to close up the holes in the top of the bottom portion of the plenum and then the 2 center posts filled the remaining 2 holes. If there are 2 solid posts now in the center of the plenum, will we have to screw in two screws like the other 4 and then the posts will rest on top of those screws? I'm not really sure how or if that will work??

-Chris

 

I just recently replace my cracked V2 which was still running fine with V3 and I notice the V3 sound not as loud as V2 like it doesnt get as much air as V2. Anyone going from V2 to V3 notice this?
I hope V4 doesnt reduce air flow to like the stock one with build in posts.

 

My guess and its only a guess is that the 2 center posts will be integral to the plenum (like the stock)and will mate to the lower plenum. They will be hollow on the inside (like stock) with provisions to again bolt them to the lower plenum just like it is with the earlier versions (and stock).

With an integral design the load(s) will be more evenly distributed rather than localized at the bolt holes as it is with the v-1,2,3, versions.. Again only a guess.

 

Well, I am not sure about that because they said that there will no longer be mounting holes in the top since that caused the stress cracks. I really don't know all the specifics, but I am very curious about how the posts will work with the holes in the bottom of the plenum? When someone gets a new V4, PLEASE take a picture of the inside and post it up here so that the answer might be apparent.

-Chris

 

maybe just supports, as the pressure is downword, maybe they are just supports that butt up to the bottom, but not actually screwed in. so the top cant push down, but it could push up, it just wouldnt. but this kinda introduces a problem for FI as then the pressure might force it up, and it lacks anything holding it back down.

theirfore Id assume what Ijust said isnt true... and if it is... we'll see. but you cant have screws without a screw hole on top. so no matter what I dont see how it can hold itself down for FI.

 

Yeah, I would definitely NOT use this plenum for any form of F/I. I would wait until they come out with their F/I Specific plenum or go with crawford. You could even stick with the OEM plenum with F/I with no problem.

 

Well I ordered the Kinetix resonated test pipes...sounds like they're working better than the plenum. Although I must admit, I ordered them from them simply because no one else I know of makes a resonated version.

I think Kinetix should do more field work on their plenums before they start shipping them to people...Why ship a V3 if they need to make a v4 a month later? Just seems bizzare to me. I guess they don't want to loose out on any orders, but in reality I think they're going to hurt themselves in the long run.

 

I don't think that they are making plenums with the thought that they will have to make design changes down the road. I believe that each one they produce is done with the thought that it's the "last one", but after being installed and used, they discover that there are flaws that need to be resolved, henceforth the next version. I really don't think they are sitting around going "Let's get all these V3 plenums shipped out to make room for the new V4's that are being made."

-Chris

 

I agree with Chris here. I think that anytime a company designs something they believe it will work as it is supposed to. Think about it, each plenum returned is less profit that they are getting. So they would not make a plenum just to get the V3s out so they have to spend more money to replace each newer version. Correct me if I'm wrong here but isn't Crawford on their 5th version. Kinetix = V4, Crawford = V5. Hmmmmm. Sounds to me like Crawford is in the same boat as everyone is saying about Kinetix. By the way, don't think I'm ******* Crawford because I'm not. I know nothing about Crawford or their products. I'm just stating what I have read on this forum. I have a Kinetix V4 plenum on the way and i'm going to stick by Kinetix on their products. If the V4 cracks, then so be it. I'll just get it replaced. This way, I learn more about the car!

Zach

 

"but after being installed and used, they discover that there are flaws that need to be resolved, henceforth the next version"

Which is why they should be testing them on themselfs for a MUCH MUCH longer period of time before introducing it to the market. Sure they would not have gotten started as fast, sure people would be waiting and waiting, but it would make for a happpier customer in the long run and less bad words going around about their products.

Nismo for example tests their parts for daaaaaaaaaaaaaaayys. As we all know they are all quality.

 

crawford is on V5, but to this day I havent heard of a single one failing structurally. the versions were cosmeticly related. crawford will admit that their earlier versions were butt ugly. theyve refined their process over time. old versions were not replaced, as they were not broken.

 

Is the performance alot better than the Crawfords or what because i haven't heard of any problems with crawford? I dont understand why you would choose a part for your car that has a history of breaking when theres something out there that doesn't.

 

i believe the gains were quite similar.
the main reason why people are not going with crawfords is probably due to the fact that you cannot use the oem engine cover or strut bar. crawford does offer an aftermarket strut bar with their plenum for an extra $185. also with the crawford, you need to send in your oem plenum, or pay $200 to keep it.

with the kinetix you can keep your oem strut and engine cover, but take the risk that the thing will crack. and then starts the constant sending of plenums back and forth. not to count the time spent installing and uninstalling the plenums.

so in the end the crawford is more expensive but more reliable. and the kinetix is a little cheaper, but the chances of cracking are there.

 

v5 is the model, but not the fifth variation....

 

but there were 4 models before it.