Do you have any data to back that up?

 

MechEE,

There have been many independant dynos of both configurations posted. Although the peak added HP is roughly similar, the MREV+ has consistantly shown more area under the curve and less of a loss at the last 600 RPM's.

Each car seems to take to the mod differently but the pattern of MREV plus is showing consistantly better. The first two dyno plots posted by Klumzyee at the beginning of this thread is a good example of the differences seen between the modified and non-modified.

The runners are not ported, the modification is a milling process by which a significant amount of aluminum is removed from the top portion of collector. This allows for more flow area in the one key area of the plenum assembly. This area of the stock plenum assembly is what started the whole plenum mod business for the VQ. The flow restriction almost amounts to a design flaw where runners 1&2 have restricted air flow because the top of the intake runners is only 1/8" away from the top of the upper plenum. 1/8" isn't enough room to allow the engine to breath.

On the 287 HP engine, plenum spacers (or new plenums) fix the air flow restriction and allow for more power. This is old news. But on the REVUP engine, it doesn't quite work the same. First off, none of the old plenum mod science works on the REVUP engine. The only effective modification is MREV. And with the MREV installed, testing shows bigger isn't necessarily better. When MREV is used, there is a tradeoff between HP and TQ as larger spacers (or plenums) are used.

With no plenum spacer at all, MREV produced the most TQ but it took a big hit on the highend HP. It would be great for daily driving, but the loss up top was too much.

With the 5/16" spacer installed on the MREV, there is a significant increase in the highend HP, but there was also a small loss of TQ. The large gain in HP was a good trade for the small loss in TQ. And the TQ was still vastly improved over the stock manifold.

With the 1/2" spacer installed there was approximatly 2 HP more in the high RPM's but there was also a significant loss in TQ. It wasn't a good trade relative to the 5/16".

Seeing how the different spacers affected the power curve, it basically shows that plenum internal volume should be minimized if you want to maximize TQ. The testing also shows that by maximizing the flow clearance above runners 1&2 you can increase HP at high RPM.

These are competing variables that trade one for the other. It begs the question, how can the best of both be obtained? Is there any kind of work around? ... Machining down the the top of intake runners 1&2 is a workaround. It doesn't add volume to the plenum, but it will add more flow area where it is needed most.

The total added flow clearance with the machined runners does not quite add up to the clearance of a 1/2" spacer, but it is close. And of course, there is no significant additional internal volume generated by the modification, so you can maintain the TQ of the 5/16" spacer.

At a minimum it can be said the collector modification is good for 1-2 HP. (And I have posted 1-2 HP on several threads here and on 350Z.) When you look at the independant dyno plots that are being posted, it appears there is a pattern of significantly more area under the curve being generated by modified collectors.

It can be said that it does more than 1-2 HP but I'll keep it on the conservative side and leave it at 1-2. I am also confident that it will do at least that much. MREV is also advertised as a 15+ HP mod even though all the independant dynos are consistantly showing higher numbers.

I believe it is better to underate rather than exaggerate so there will never be any disappointments. And if the bolt on meets or excceds expectations, its all good.

 

DaveB,

I measured a 30-60 degree F decrease in plenum temperature with Iso Thermal installed. OCG35 measured his deltas over a two week period at about 40-80 degrees F. Thats a pretty significant drop in temperature.

I was able to calculate the total heat flux both pre and post Iso Thermal to estimate a delta in air temperature. Basically to make a long post short, I calculated the Iso Thermal is good for about 1-2 HP. Its not much, but when enough elements like this are added in, it starts to add up.

And when competing in a world of other plenum mods on the market, there is no reason to stop at just good enough.

Chances are that if its a design feature I would like to have on my car, its probably what most others would like to have on their car too.

 

45 degree track day. Scalding hot intake manifold after driving 45 minutes to the track. 14.32@97.79mph with a 2.15 60'. Cold intake manifold after sitting 1 hour. 14.38@98.0mph with a 2.17 60'. Same stuff goes for when I ran back in May is much warmer weather.

The engine is a pretty big mass of metal placed inside a small box. When it heats up, it heats up everything. It even heat soaks the plastic intake pipe, the battery, etc. There's no way of getting around radient heat.

The ambient air intake temperature is far more important than the heat of the intake manifold. The air is being sucked in a rapid rate and it really doesn't have time to heat up as it passes through the intake manifold. For ideal power, you want cold dense air and a very hot combustion chamber (hot block/heads). If it's 90 degrees outside, the VQ is going to be a slug regardless of if the intake manifold is cool or hot. As ambient temps rise, there is less 02 in air. It's as simple as that.

 

I must beg the question, how was temp measured? Were the intake temps measured or did you use a Pyrometer on the intake manifold? Using the intake temps would be pointless seeing that intake temp is measured at the MAF.

 

Measurements were taken directly from the plenum itself and measured with an array of thermocouples. I had thermocouples all over the plenum, inside the plenum and even on the bottom of the lower plenum.

OCG35 (Mike) used a pyrometer to take his data points and used a consistant precedure every time. He used his regular commute and took measurements over a two week period. Mike also did a really good job on documenting the results into a spread sheet.
I think he posted his review of Iso Thermal in the Review section.

 

Soooo..........no data. Gotcha.

 

38,341 views and still growing. I wonder how big this thread is going to get?
Wait tell, Tony releases a few more of his Item's. I wonder if this is the biggest thread yet?

 

Ok. There is more in life than 1/4 mile times. Another thing here - if you can decrease the temps of the air going into the engine why would you NOT do it? Assuming that the decrease is only a few degrees (which I will believe Tony that it is NOT only a few degrees) then that is still a lower temperature. If you don't think a few degrees matters then you should pull up one of those atmosphere correctors you are so damn fond of and plug in a few degree difference and see if it changes things. Those are as good as gospel to you apparently so that might set your mind at ease.

 

Yep, absolutely no useable data.

I thought you swore your new "intercooler" setup was going to lower you ETs and improve MPHs; however, you never posted your new 1/4 mile times from last month.


Correct me if I'm wrong, but isn't the point of the mod to improve performance?

Sure there's more to driving than the 1/4 mile and you're missing my point. The manifold is going to heat soak after a while. Whether the manifold is 130 degrees or 160 degrees. There's no way of getting around it. Even my friend's plastic Kintex intake manifold gets hot, though it won't give me 1st degree burns like my manifold will when it's hot I don't doubt Tony's product does in fact lower manifold temps, but how much do you think a hot manifold will warm up the incoming air? With temps in the 20s and 30s in Kansas City, my intake manifold stays cool after 30 minutes of constant driving and assuming jump out of the car right away and touch the manifold. If I sit at a light for more than 30 seconds, the manifold gets warm. If I turn off the car and let it sit with the hood down, the manifold will get hot. My point is when the car is being driven and you have a stock style intake, the natural movement of air at speed in the engine bay and the intake charge will cool the manifold. When you stop, the temps will rise. It's natural.

As for the density altitude atmosphere correctors, if you don't believe them, fine. However, if you're an NHRA driver or more importantly an aircraft pilot, knowing DA are very real and honest and could mean an engine stall at altitude. Ambient intake air is maybe going to warm up 5-10 degrees as it passes through the entire tract intake. There are laminar flow vs heat formulas to calculate this stuff, but I don't have them nor do I have the time to always be calculating things for others. When it's hot out (usually teamed with humidity), the VQ is a complete dog whether the engine is hot or cold. When it's cold out and your VQ is hot, the VQ still hauls butt. So many people think it's the hot engine that's killing the power, but in reality it's really the ambient conditions.

I've dealt with phenolic spacers before on Contour SVTs, Mustangs, Hondas, etc. Yes, you do see reduced manifold and throttle body temps, but you'll never see any of them have legitment improvements in the 1/4 mile.

 

www.sah2o.com/intakeproject.htm has my results on the temps as well. There was a huge drop in temp. You could not keep your hand on the intake manifold before the thermo gaskets. Now there hasn't been a time it has been HOT. And thats even after racing at the AUTOX which puts more heat on the engine that the 1/4 does.

There is a way. And again you don't know what your talking about.

 

I didn't say that I didn't believe them. Don't put words in my mouth - most people would agree I say enough ALL by myself. I just don't seem to feel the need to nit pick everyone about them. You have often seemed a bit hung up on them. Again, you admit that there is a likely raise in temp of 5 - 10 degrees in the air as it passes through the intake tract. Assuming that is true then it is certainly enough to have an effect. Plug in a temp 5 degrees higher in your DA calculator and see if it doesn't make a difference. Will it make a massive difference? Likely not, but Tony has claimed a gain of 1-2hp and that is not a massive gain.

 

It is posted... And reviewed many times over in many threads. The way I see this and all mods is: If a vast number of people have tried and tested a product and have positive results and opinions, there must be some validity. Not every person using these mods are sheep and ignorant and just spend the money because one (or a few) individuals say they should. I've seen soooo many pages of debate on issues that have 90% in favor and 10% opposed. It just gets ridiculous. If you don’t like the factors that are presented - it's simple, don't use the mod. There are plenty of people that have had positive experiences and that should not consistently be met with debate.

Let's move on now.

 

Do Tell Pasta!!!!!!

Tony - Please oh please go old school and give us non revups some TQ!!!!!!!