Why do you think the TopSecret plenum will benefit FI only?

 

Because it is so large inside (obviously) that the decreased air velocity will hurt NA. FI forces air into spaces anyways so it should help FI produce the same power at lower boost.

 

thanks mike. (hehe)

so are crawford and the pending lsdunique the only NA solutions still?

 

hrmm.... well, if Larger inside decreased air velocity in that plenum and it is only for FI... then....................

 

It will also be good for NA motors that are built to turn high RPMs and I don't mean 7K. There will be a torque loss. It will probably make power up around 9K. So it is much more suited to FI. LSDUnique is coming out with a NA version very soon and a FI version a little later. The FI version will also replace the lower manifold and I guess be a little bigger though I have not seen a close to production version yet.

 

Also Top Secret wont sell the part seperatly, you need to buy their turbo kit to get it. Last I heard.

 

Any clue on the cost of the kit or when it will be released?

 

I only got a ruff quote from someone here in Sydney. It was about AU$14,000 or ~US$10,500, but I dont know if that was installed or not?? And you can't just do a simple conversion like that cause shipping would be different, duty, labour(if thats in the price), etc etc.

And no idea on release.

Murray

 

It's due to the design of the plenum.

 

2.

 

12secZ, what are you referring to? The original question? If so, just to let you know that prototype pic of LSDUnique's plenum is not going to be used. That design with SMALLER runners and overall inside volume will be used for FI. A more Crawford esque style plastic plenum will be used for NA. So, overall, it is due to the design of the plenum being so large inside. Is that what you are inferring? Because I have no idea.

and in reference to the second pic which was posted while I was typing that, the LSD FI plenum will also include a replacement for the lower portion in the second pic. I have no idea if this is what you are saying already.

 

having our car rev up to 9rpm = less torque for us right?

 

I was reffering to FI and that is the TS design and I have FI.

I haven't seen any other pics of any plenums since that was posted. I understand an N/A version is being made, I was attempting to show how an FI setup would benefit more than an N/A with that design.

Would love to see more pics because TS told me theirs is not for sale as a stand alone.

 

the pic you posted is LSDUniques prototype.
https://my350z.com/forum/showthread....ghlight=plenum

same concept as the TS. too big inside for FI so LSD is resizing it smaller for FI and has a different design entirely for NA. Still not sure if this is what you are saying.

 

Interesting about the lower portion being replaced too, should work well. I didn't know he was doing that. I only *wish* I had stayed N/A 15K ago!!

That is an interesting thought process to pursue.

The Crawford make power both N/A and FI (I have raced it both ways and even with N20) but it does increas the interior size as you state above.

So that in of itself is interesting to me. Plus it leans you out on FI you have to make adjustments.

 

Our posts are coming in at the same time.

TS didn't change their design though for Turbo did they? Why not?

I want to see more current pics of LSD's products I have followed his posts since his very first post here and was interested in his FI plenum but got impatient (I do that quite often.) lol

 

it doesn't have to mean that. it could also mean a lot more power at 9K. but to just put a plenum like this on would mean less torque at the low end yes. you would need more RPM to create the HP.

for those that say FI is the replacement for displacement, that is not correct. You can always add FI to a bigger motor. The only real replacement for displacement is RPMs. and even that has limits.

 

there are no recent pics of either the NA of FI plenum from LSDU. The prototypes of the new versions will be dynoed within the next 2 weeks and brought to market shortly thereafter.

as far as TS changing designs I do not know. i have been referring to the latest pic posted on another thread that this thread is in reference to.

as far as internal volume, the Crawford plenum is not tons bigger than stock, just enough in front to even the flow to all cylinders. The FI LSD plenum and the TS plenum are shaped to allow A LOT more airflow to each cylinder but are too big to allow much air to actually make it to the cylinders for NA since NA sucks air in at a much lower rate than FI pushes air. If that makes any sense.

Think back to muscle cars and Edelbrock manifolds. Remember the characteristics of a Performer compared to a Perfomer RPM compared to a Victor Jr. intake manifold? Check out www.summitracing.com and look at the pics and recommended applications for easy reference.

 

I had a high rise Edelbrock Manifold below a Holly 750 Quad Carb on a 1970 Camaro and blew out my bottom end lol, I remember w/o going to look at pics. I built up the top end (chrome valve covers and breathers etc, but not the bottom end and BANG!)

I also remember watching a video on here of Doug making the plenum where he said ideally it would be larger if not for the Z hood. More air in will effect your A/F Ratio too right ;how is this being addressed N/A with ALL plenums

Anyways I guess my post was to address why that original design was better for FI than N/A and I do not have any other pics to base that on although again can't wait to see them I am sure they will be great!

More air in is a good thing on our cars, with FI Blower you get this already so the pleunums for FI Vs N/A would need to be different?

If so why doesn't Doug have a N/A and FI plenum?

Guess I am causing more questions than answers lol, sorry. Just sorta wondering about this FI plenum question aloud because I too am curiuos.

 

Well, I have not scienced out the Z plenum as LSD and Crawford have been working on. I am sure a little more volume could very well be a good thing. My impression is that the molded plastic NA intake from LSD will have more internal volume than the Crawford but I have no idea in reality about that. With the ability to mold the plastic much better than welded aluminum, that is the impression that I get.

Anyways, just think of the intake like a properly tuned exhaust in reverse. Air velocity is important as well as low restriction. The Crawford plenum nicely addresses the restriction issue and allows air evenly to the cylinders. But it is not so big (a dual 5" exhaust) that air can hardly flow through it. With separate runners for each cylinder, it is easy to make them too large as they are not being shared by the whole motor like the Crawford plenum and stock does. This is a characteristic of both the LSD FI plenum and the TS plenum. They are so big inside that air cannot flow through very fast. Remember Tommy Kaira's individual throttle bodies? Ignoring the fact that they are open under the hood (hot air) they are very short in runner length. Much better power at lower RPMs and better throttle response compared to the stock setup. The longer distance the air has to travel the longer it will take to make power after you open the throttle. I am starting to lose myself, but you have to be getting it. I know you do so I am done with this explanation.