After my NA engine build is complete (build link), I plan on performing a plenum test prior to bringing the car home to help out those looking for a good plenum for their non FI car. Below are the plenum configurations I plan to test and the ones I will be receiving from the manufacturer or have bought previously.

1. Cosworth Plenum (personal item)
2. Motordyne ISO 5/16" + MREV2 (provided by Motordyne Engineering)
3. Skunk2 5/8" Spacer (provided by Skunk2) + Revup Lower (personal item)

I was intending to test the Powerlab 3/8" spacer since it's quite a popular one but unfortunately I have not been able to successfully come into contact with Intensepower/Powerlab.

Edit: I've also omitted the Kinetix as well as the Crawford plenum as those have been already proven to be worthless for NA application.

Edit to: I've omitted the Kinetix SSV as it has shown disappointing results on NA cars. Crawford was also left out as the performance is very similar to a spacer but at a higher price.

If anyone has any suggestions please let me know. Test will probably be done in a few weeks. I'll keep things updated as I get more information.

Update 10/29/2009: I just sent an email to Kinetix Racing to see if they would like to provide a V+ for the test and if they believe my statement on the SSV is incorrect. Also I've updated the paragraph to clarify things about the Crawford and Kinetix.

 

it will be interesting to see... however, the results wont be viable for the majority of NA cars... I suspect you will benefit from the Cosworth (with your build) much more than a typical DE would... in fact, all the results will be different for you than most.

Interesting project though.

 

I have another thread on the same exact topic on my350z with much more inputs. Perhaps for a guy like you it may be interesting to hop over there.

These kind of technical topics always seems a lot more popular on that site since guys are a little more technical there. For this thread I'll just post the results when I am done. Just posted here since some guys here never go to my350z.

 

yep I know... I used to spend time in the NA section... I have some threads about my moderate stuff...

But some pansy kooks in an FI thread that couldn't handle the fact that I wouldn't join their bandwagon cried to their admin friends and had me banned... so I cant post there anymore... I check out the NA section every now and then though.

 

Are you sure your statement on the Kinetix is accurate since their pleunum was re-designed?

 

This is concerning the SSV, you can take a look over at my350z.com the same topic has been discussed as well as the crawford piece. However there is a general consensus that the SSV doesn't do much, I'd be happy to test one if I can get one but other then that I will fall back to what has been previously noted.

 

we all know that the ssv is garbage for N/A it's just for bling. He is talking about the composite one the V+. I didn't know the crawford was garbage isn't it similar to the aps plenum?

When do you expect your car to be finished?

 

When I mentioned worthless for the crawford, it was more in regards towards the higher price you have to pay for the unit and the relatively similar but lower performance compared to the MD spacer. Sorry for the confusion.

I expect the car and test to be done within a one month. I'll post the results as soon as they come available.

That's too bad that you are banned from posting. This is the problem with forums sometimes at least you can still read.

 

interesting cant wait to see the results

 

Crawford expensive? think I paid $400 new for mine back when they first came out with the V5. this may be a little more than a spacer, but much less than most plenums out there. this piece was proven to make power and I had read several tests in magazines and forums that had proved it before it bought it.

unfortunately I did not save the dyno, but when I originally had my Crawford installed on my previous early 03 sedan it did not lose any power, so I swapped it over to my current 05 coupe. the Crawford gains are in line with most spacers.

I think you were a little hasty in declaring this part worthless for N/A applications. my current N/A setup of bolt ons, including the Crawford, does quite well and so far I have never lost any power.

in fact I had a discussion with Tony @ Motordyne and he confirmed that the Crawford combined with the MREV2 will give approx. the same gains as a spacer and MREV2 and there was no reason to exchange.

from what I know Crawford no longer produces these, otherwise I am sure they would be happy to supply one for your test. would give you mine, but I am happily using it and getting ready to add the MREV2 to it for even better performance.

 

I don't disagree...but the extra money you pay compared to a spacer is worthless. Other plenum designs like the Kinetix and Cosworth are completely different in design since they include both the upper and lower part of the plenum, which modifies the intake runner... If you do the math then crawford + mrev2 is not too different then kinetix SSV or Cosworth, price wise.

 

that's the whole point, same gains 2x the cost of a spacer

 

From feedback the feedback I got here and my350z, I updated my first post.

 

A little VQDE Plenum history lesson (for those that care) ~

Crawford was the first plenum that addressed the issue of front slope (front two cylinders starved for air) – and it worked great.

That very plenum is what gave birth to Motordyne's spacer (and ultimately the company in general)… Tony was looking for a cheaper way to accomplish what the Crawford plenum did. He realized you don’t need to go to the extent that they did – and he set out to find a machinist to make the spacer. Initially he wanted it just for himself (he started as an enthusiast with a G35 sedan) - but as we all know, it became a hit once dyno test were done and now it’s available to the masses.

A little known fact though is that MD wasn’t the first spacer to be made… there was a composite version out of Japan (I always forget the name, it's a known company)… their version was extremely expensive – which is another reason why the Motordyne version became so popular, it was/is affordable.

So anyway – the Crawford works well – but it’s pointless these days since a spacer does the same thing for less money. *Incidentally, the success of Motordyne’s spacer is what ended up being the demise of Crawford’s plenum… way back then there were forum wars about the two mods (Crawford’s camp tried to slam MD’s product)… I don’t believe you can even buy a new Crawford plenum even if you wanted to (I could be wrong, but I’m pretty sure Doug stopped making them).

Okay – back to your regularly scheduled programming.

 

^Good to know.

By the way. I got into contact with Kinetix and there is an improved version of the "SSV" called the "Velocity Manifold". I asked them to see if they are willing to provide one for the test. Their claim is +30hp at the top end over stock.

Here is a link to the same thread over at my350z.
http://my350z.com/forum/intake-exhau...tout-test.html