As some of you may have seen, I dynoed at 340whp/wtq with my 5000 series turbo (GT30 equivalent). It's a small turbo and reached its efficiency range at around 8-9psi. Here's my question: I currently have a Kinetix V+ plenum, and dynoed using it for the 340whp/wtq. My tuner believes I may have better results by replacing the V+ plenum with my stock upper plenum. I'm trying to wrap my head around what reason the stock plenum would yield better results than the Kinetix V+...any thoughts??

My only thoughts are: more air flow=more power and a different aspect being that less intake flow, or more pressure, created may lead to better performance...?

I know I just butchered ^ all that.

 

If you maxed out that turbo air flow, no matter what plenum you put, will not gain more power.

 

I know that the turbo is maxed out. But power is created by increase in intake pressure vs decrease in exhaust pressure (my vague understanding). So I am planning on doing this, because I'm quite honestly not very sure that the V+ will hold up over time (hardened plastic plenum), and it won't cost me a dime (I still have stock plenum, and will sell V+ to cover dyno time), and lastly, I trust my tuner and would like to see if I do gain any power.

The previous owner had this exact kit and made 360whp on the same dyno on only 6psi, but didnt have the v+ plenum. Not saying I will make same power as he did, but i do wonder if the v+ is hindering my performance on this app.

 

That is around 5%. Due to the many, many variables at play in dyno testing such as humidity, dyno repeatability, ambient temp, etc I would not call it significant and not use that as a decision to change a part.

 

I agree with you on both parts. My reasons are:

 

Yeah. I wasn't arguing with you - just making sure that you weren't basing too much of your decision on his 20hp.

 

These are the turbo specs (the turbo you have in there):

Specifications:
Suggested application: 1.6L - 2.5L engines
Turbine Housing: free float
Single:A/R .36, A/R .48, A/R .63 / T3 flange with a 4-bolt downpipe flange
Compressor Housing: A/R .50 please see technical drawing
Notes: good up to 500 HP
Average weight: 9.0 Kg / 19.73 lbs
Compressor TRIM:50
Turbine TRIM: 73

Please note the bold...no matter what you do, you will not make more power. I mentioned this early in your build thread on driver. Buy another turbo that size, and add it to the build, then you will make some power.

 

I understand, I'm just trying to clarify the overall reasoning I have I mind. It will be free, it will be more reliable, and performance(?).- I agree NO big change will happen. No question here. Thank you for the input.

I am well aware of the turbo's specs, and the fact that it is small for our engine. I'm not trying to make massive power. I appreciate your input, although I feel you did not read my post carefully enough or understand what I wrote perhaps.

The stock plenum will be more reliable(than the plastic V+ -I've heard of them cracking).
It will be completely free, at the end of the day, to install & retune with oem upper plenum (via selling the v+).
The performance MAY be improved (slightly!). <this is the part I'm not sure on.

I read your post where you say "no matter what you do, you will not gain more power". To me, "more power" could mean any gains (>0hp), to you "more power" may mean large gains (>50hp)- I don't know. I wholly disagree that >0hp could not be gained on any setup, turbo or otherwise. However this is not my main focus.

I believe you know much, much more than I do about FI. I'm not questioning that. However, I am astonished that you would make such a generalized and untrue statement- "no matter what you do, you will not gain more power". That would mean that back pressure has NOTHING to do with engine power made FI. That would mean that timing has NOTHING to do with engine power made FI...as well as many other aspects.

 

we seem to be going 2 directions. one is you getting more power.. the other is your tuner telling you to ditch the kinetx.

I owned the kinetix na and i had the latest version.. it still leaked.
the bolts are less than hand tight. as in 8-10 INCH lbs of torque.. not ft lbs. Id not run FI thru one out of safety. Im not just talking out my @ss either lol.. i went FI and ditched mine. just like ur signature says, i didnt want any issues over something stupid like a cheapo plenum.

The reccomended set up aside from Cosworth etc.. is the stock plenum, an aluminum plenum spacer, and to really max it out, an MREV collector (depending on your existing engine)... and an iso thermal collector gasket.

 

The statement is true. Sure you can change the plenum, improve flow on the charge side, but your turbine housing and wheel are staying the same. This is why you will not be making more power. It is the choking point of the system. You can get a 5" exhaust after the turbo, but it won't do much. It will change the curve a bit, but the max power/torque will not change a significant amount (+/-10hp). That is all I am trying to say.

I understand that you are chaning the plenum to be more reliable, but you also mentioned better results, hence my reply..

 

You are correct. My tuner wants me to ditch it, but also think some amount of power, however insignificant, can be had by doing so. He and I both agree that Kinetix has had some issues of reliability, which is a good reason to ditch it already.

 

Here's what you do.
log a pull with the V+ plenum
swap to stock
log a pull with the stock plenum
if you dont see a drastic change in AFR, then you will not see anything on the dyno.

You are running so little boost, whatever plenum you use will be reliable.

 

Gotcha, thanks for the input.

 

I would like to switch out on the spot and compare, howeverthis is not solely about gaining power, and I will have to switch out the plenum before going to re-dyno/tune.

My opinion, contrary to your last statement, is that 8-9psi is enough to blow apart that Kinetix. I do not feel confident in it's durability, even though they claim that it's good up to XXpsi. Yes it's a small turbo, however, its forcing enough air through that I gained over 100whp/125wtq in parts of the powerband. I don't trust the plastic the more I think about it.

 

I thank you for your opinion, and in this application you may be 100% correct, we will never really know -even though i will dyno on same machine, there will be many variables of course, temp, hum. etc...

I truly do not believe that power cannot be made as you claim though, with this turbo in place. That would mean that upgraded cams=nothing, cosworth plenum=nothing, nitrous=nothing, built engine=nothing, anything else=nothing. I'm not going to do any of that stuff, but I know for a fact that just removing the air filter alone, has yeilded 20+whp on turbonetics kit (not going to do that either). This isn't a horsepower easter egg hunt, I just wanted to know opinions on whether or not this change held theory. I have your answer, and I thank you for that, but I disagree on your reasoning, still.

 

i dont understand this thread is your mind is made up.

please close thread.

 

Beat me to it.

 

lol yup.. ditch the kinetix.. its cool when youre NA as the sound it makes is very unique at low rpms , parking lots etc.

But i carried a ten mm hand driver and carb spray everytime the weather got really hot outside as it would ALWAYS start to squeal w vacuum leak on heat soaked hot starts.. clearnaces change, its plastic, the rest of what its bolted to is metal, etc etc.. just was what it was.
I think the top that you see is less important for "heat soak" thatn the lower collector and runners anyways.. I say ID IMAGINE thats the case.
spacer, mrev and iso thermal.. they arent part of your posts issue, but if youre going to wrench off a plenum, might as well swap in those parts too.

 

I'm not sure what is not to understand. I will be doing the swap. I'm asking if there's any theory behind why the OEM plenum would yield gains over the Kinetix V+, in this case. If you don't know the answer then......you don't know.

 

Its was answered for you already... at least twice.

Fixed and your wish is my command Rich