hacim105

iTrader: (6)

I was looking through the 3rd Gen forums and came across a thread about a plastic spacer that goes between the upper and lower IM. The purpose is to resist heat transfer and thus help keep the upper IM cooler, which would mean cooler air entering the engine. However, this mod will only be beneficial to those with the USIM and the MEVI, seeing as the 00VI is already made out of plastic.

The tests undergone and the results of the mod were quite amazing. With a heat soaked engine he was able to average 5hp and 8tq higher with the plastic spacer. Here is the link for others to look up and enjoy.

http://forums.maxima.org/showthread.php?t=511517

Now Aaron92se is the maker and said he would be interested in making a spacer for us 4th genners provided there was interest found. There is some cause for concern with regards to the EGR connection, but if this problem can be overcome this would be a great mod for us. So please read through his posts of the thread and post opinions here and possibly we may be able to get something going.

KsuMax

Is it going to still be $35 + s&h?

90stanza

I'm intrested

bpk01

I'm interested

XAugusta MoonX

iTrader: (1)

Ditto to above statements

Blackwind

iTrader: (9)

no, the egr adapter will most likley be the cheaper of the two components. it sounds like he will fabricate a new EGR tube to use with this spacer. but this sounds great. im in for this.

scrhale

Spacers also shift the powerband to the right ... although this one is probably much smaller than those designed to do so, it can be the reason that the 5 ponies are gained.

Aaron92SE

iTrader: (128)

In theory, the longer the intake runners, the more the powerband should shift to the left, providing more low end power and losing top end power.

But this is NOT the case with my spacers. I noticed a NICE low end power gain and still gained top end horsepower, probably due to the lower intake manifold temps.

These are Phenolic Intake Spacers, which will prevent heat from transferring to the upper intake manifold.

I have not been able to get my hands on a test vehicle in my area, but as soon as I do, I will go ahead and design this and see what kind of EGR and coolant problems I might run into.

Here are a few pics for the VE30DE kit.

supazn

Isn't it possible to just stack them then? will this provide the same yields for the VQ?

Kevlo911

iTrader: (36)

Looks like good stuff. If I had a MEVI or the stock IM I would DEF jump on this.

Aaron92SE

iTrader: (128)

Yes, you can stack them if you REALLY want to lengthen the runners. But even longer bolts will be needed.

I expect the same gains to be seen from the VQ30DE. If I'm able to bypass the coolant somehow, it will help a little more. It all depends how much the VQ30DE is effected by heat soak.

hacim105

iTrader: (6)

But this isn't just 5 peak hp. It's an AVERAGE of 5 across the powerband, and mind you these tests were also done after really trying to heat soak the engine. Which really proves how well the Phenolic Spacer actually works. So this will really prove beneficial in summer months when temps get high. A 40-60 degree drop in temperature is quite impressive. So while part of the hp gain can be contributed to the lift the spacer provides, it's probably more so the resistance to the heat transfer.

So now what we need is someone in or near the Snow Hill, NC area. We bid you to offer your car for testing and fitment.

dgeesaman

iTrader: (10)

Dyno testing 16x is pretty extreme. Engine bay temps will go up under hard driving, but the heat soak possible on a dyno is way tougher than road conditions.

While I'm impressed with the simplicity and the theory supporting this is sound, I would like to know if there is any power difference on the first one or two dyno runs. I suspect there is not - I see this as a 'heat soak insurance' measure.

Dave

Aaron92SE

iTrader: (128)

I have a one hour long testing procedure that I follow before every dyno session. First, I start the car and allow it to warm up at idle until the fans kick on around 210*F. Then I very aggressively drive the car around the block (2 miles) and then park it and allow the cooling fans to cycle on and off a few times. All this time, I am taking intake manifold temp measurements. Then after about 40 minutes of abusing the car, I do 8 dynos back to back all within 5 minutes. Then I park the car and allow it to idle for another 15 minutes while taking temp measurements every 1 or 2 minutes.

This testing is WAY extreme, I know. But there is no better way to heat soak the motor than to let it idle, with the hood closed, in gear, and allowing the cooling fans to cycle on and off repeatedly.

So to answer your question, No. The first couple dyno runs didn't show a noticable gain in power over the later runs since I fully heat soaked the engine before conducting any testing.

Also, let me mention that this was not done on a chasis dyno. This was done using a system called Home Dyno. Home Dyno is software that takes the spark plug pulses using an inductive pickup and puts them into a laptop. Once this data is recorded, it uses the car's parameters to calculate acceleration, therefore calculating Horsepower! This system is just as accurate as a chassis dyno, in fact, it's more accurate when you take into account you are actually accelerating on the road. The only difference is instead of using the rollers, you have to use the street and the actual car. So there are certain parameters that can't be figured precisely (ie, drivetrain loss, crosswinds, frontal drag, etc). But the gear ratios and curb weight are the most important parameters and that will allow me to get close to the same HP output as a chassis dyno would show. The main purposes of using Home Dyno is to ACCURATELY do before and after comparisons such as comparing the gain that phenolic intake spacers have on the street.

Please note that ALL my dynos were done with the exact same weather conditions, same road, same routine, and same vehicle parameters.

So, the gains shown in the dyno results are true and as accurate as you would see on a chassis dyno. Both sets of dyno runs were done on a fully hot motor after a half hour of racing and idling.

I used every rpm point for each of the dyno runs, averaged them out and plotted the point. After doing this for all the rpm points on all 16 dyno runs, this dyno chart was created to show true average power increases. It took me several hours to average out all 16 dyno plots at every single 100rpm increment!

hacim105

iTrader: (6)

While this is true, for those that go to the drag strip, this will help tremendously because we're always worried about heat soaking. And I think the main purpose of this is to prevent heat soak. But if in the meantime we can gain a little more hp that what do you have to lose?

alcatranz518

iTrader: (8)

I would be interested as well.

shiftnatredline

iTrader: (1)

I'll take one.

jvelos3

iTrader: (2)

very interested over here

pod97654

iTrader: (13)

sign me up, sounds like it's well worth it

TurTLe*

iTrader: (11)

but this is only for people with stock and mevi's then. how diffrent would it be if you had a MEVI and a stock IM. as i do have MEVI coming from overseas =P

Kevlo911

iTrader: (36)

What?

Aaron92SE

iTrader: (128)

I plan to design the spacer kit around the USIM. But if the ports and bolt holes on the MEVI are identical to the USIM, then this spacer kit should work. I just might have to make some minor changes if the bolts are different.

Kevlo911

iTrader: (36)

95% sure they use the same gasket.

Aaron92SE

iTrader: (128)

Gaskets are usually slightly oversized on purpose so it doesn't overhang the lip of the port obstructing the airflow.

So, the ports from the MEVI and USIM might be ever so slightly different. If they are, then they may be port matched by hand. If not, I'd have to create a completely different drawing to get a new batch CNC machined. It would be a completely different project since I won't release something for a particular motor unless it's port matched and ready to be installed.

My spacers are designed to match the port flawlessly so there isn't a dip or bump in the airflow!

natty99

iTrader: (6)

would this require two UIM gaskets for installation?

and yes, I'm def interested.

Aaron92SE

iTrader: (128)

No, I recommend using Black Silicone RTV or equivalent.

My spacer can replace the gaskets or if you have the thin paper type gaskets, then you can use two gaskets and sandwich the spacer.

But I recommend a very thin coat of RTV on each side of the spacer. That will ensure a perfectly smooth transistion from the LIM or the UIM.

Now, if you use too much RTV, when you torque down the manifold, it will smoosh out and obstruct the airflow slightly. In my instructons, I recommend applying a small amount to your finger and apply a thin coat on the spacer.

hacim105

iTrader: (6)

The bolts hole locations and the port locations are exactly the same. And I'm going to guess the port sizes are pretty close to the same.

I'm not fretting about the difference from the MEVI compared to the USIM. If there is a difference, it's already being affected by the LIM as of now for those who have it installed.

Aaron92SE

iTrader: (128)

That's exactly right. Since this is the case, I might base my design off the top of the LIM instead of the UIM. Yes, there is always a slight difference on how the ports line up. That's why gasket matched portwork is a good thing to do if you are handy with a die grinder.

Every kit is different whether I will base my CAD drawing off the top of the LIM or the UIM. The VE was better using the UIM. On the 3.5 VQ, it should be better to base it off the top of the LIM. I will determine all that when I get a test vehicle locally.

BTW, I am only located an hour east of Raleigh and only 20 minutes from Greenville and Wilson, NC. I am also very close to Kinston and Goldsboro.

grey99max

iTrader: (12)

I propose another test.

The USIM and MEVI have identical mounting holes, and use the same thick rubber gasket between the LIM and USIM/MEVI. The only points of contact between the engine and the intake manifold (either one) is the bolts holding the manifold to the LIM, the EGR port, and the two brackets supporting the manifold on the firewall side. Of course there are a couple of vacuum ports in there.....

If there is a lot of heat-soak taking place into the intake manifold through the rubber intake gasket, there must be even more from the EGR tube - hot exhaust gases and all that. The manifold sits in the hot engine bay, and soaks up heat fron the hot air in there. I don't see how a phenolic spacer can make much difference.

I propose another test for you - heat the engine by lots of driving, "dyno" the car and record what you find. Spray the intake with CO2 until it is frosty on the outside, then "dyno" again. If there is a real difference in power between a heated intake and a chilled intake, it will be obvious - and worth pursuing. If it is, build and market a "manifold cooling kit" for those dyno runs and drag strip runs. Show me 10 real hp to the wheels and I'll buy one.

Aaron92SE

iTrader: (128)

Now you're just being difficult! Just kidding.

But since I haven't seen a test vehicle yet, I can't say anything. But a 10 hp gain is kinda high as a goal with just phenolic spacers.

The first thing I do to any test vehicle is get it as heat soaked as I can, then I record the difference in temperature between the LIM and UIM. If the temps are within a certain amount of one another, then it's worth pursuing. If not, then I doubt I'll invest the money to make a prototype.

You mentioned a thick rubber gasket. That does act as a great insulator. I've never seen what this gasket looks like. Is it entirely made of rubber? Or is it metal with rubber around each port?

With the VE, there is a thin paper gasket. The heat soak does get pretty bad. And on the 3.5L, there is a thick metal gasket that really helps transfer the heat! I would really love to get my hands on a 4th gen so I can do some testing.

dgeesaman

iTrader: (10)

Wow, that's elaborate. Thanks for explaining it.

As for the drag racing guys, I would think these gaskets plus an icebag on the manifold should pretty much eliminate temp issues.

Dave

grey99max

iTrader: (12)

I'm not trying to be difficult - just trying to provide accurate details about the intake manifold. I'm not picking on you - I know you know how to think and act on it. You just need more information here.

Yes, the LIM gasket is a thick piece of rubber - no metal in the construction. There are very few points of heat transfer between the engine and the intake manifold - that's the point I was trying to make. Only the four bolts that hold the manifold to the LIM might add to the heat transfer.

Now, if you have found the VE has lots of heat transfer between engine and intake, and a better gasket reduces heating, and cooling the intake produces more power, that's good information. Lots of racers cool their engine with bags of ice between rounds - and most of them put the bags on the intake manifold.

The VQ30 has a thick rubber LIM gasket, so improving on that would be hard. Would cooling the intake manifold on the VQ30 produce more power? How much? How could you do that? CO2 cooling comes to mind, at least for testing, because it would be immediate and effective. Fan cooling wouldn't work, because the engine compartment is hot.

Just some food for thought.... Keep thinking.

Aaron92SE

iTrader: (128)

Oh it's ok. I don't care if you pick on me. It's very likely the rubber gasket would prove to be enough of an insulator already and render these spacers useless as far as heat transfer properties are concerned. But sometimes lengthening the runners prove to be a gain. But you can't know for sure without a flow bench. Or I could invest the money in making the protoype, dyno test them and find out. But I won't do that. I will only produce these spacers if I see a temperature gain to be had.

The main purpose of my spacers are to prevent heat transfer. Once I take several temp readings from various points, I will be able to know for sure if a horsepower gain is possible.

But yes, there is a nice gain to be had with the VE kit! It's already been proven. The lengthened runners along with much cooler intake manifold temps really make a decent power gain. I just don't know right now if the VQ has the same potential. With that rubber gasket, it might not.

Also, if you cool the VQ30 IM even more, then definitely there will be a power gain! Again, I just don't know if these spacers will help the VQ30. But I know without a doubt that having an intake manifold at 30 degrees versus 165 degrees, you will see a gain. Like you said, there is a reason people put icepacks on their upper IM.

But as you know, I didn't rely on the testing that others have done with other cars. I did all my own dyno testing and took my own temperature readings. I made 16 dyno runs just so I could determine the average gain.

I can't provide any more information about the 4th gen right now b/c I haven't even seen a test vehicle yet. Once I do, I will be able to take that next step and conduct my testing.

grey99max

iTrader: (12)

Actually, the 4th gen USIM runners are already too long for racing - the MEVI and the 00VI act like shorter runners for the higher RPMs, to move the power band up some.

To test a 4th gen, you would have to adapt your dyno software to that car first, so you can get accurate readings.

Then you could do three comparisons between a run with the engine just started up from cold, a heat-soaked engine, and cooling the upper works with a CO2 spray. Nitrous would work for cooling, but it's $4.00/lb these days. These tests would define what really works.

A side note - I spray a lot (150-shot or more) so my intake gas temperature is pretty low, regardless of the temperature of the manifold. CO2 cooling wouldn't help me, but NA and boosted cars could benefit. Instead of all those icebags, make a "Race Cooler" kit that can be used as either a permanent installation or a carry-around unit like a battery jumper pack. A nitrous solenoid, some nitrous flex line attached to a small CO2 bottle, a jet or two spraying on the manifold/engine, and you could bring down any engine's temperature quickly - with off-the-shelf parts.

If a cooler manifold gives real and repeatable HP gains, you got a market for the Race Cooler.

Dark99GLE

iTrader: (2)

I'm interested, might get one if I get an MEVI

BEJAY1

iTrader: (19)

Exactly the problem for 4th gens whereas 3rd gen is a paper gasket and the 5gen metal. We looked at this 3 years ago and an independent shop said they couldn't improve. Sorry.
http://forums.maxima.org/showpost.ph...&postcount=116

Aaron92SE

iTrader: (128)

Yeah, I've already talked with the guy that got his car tested. If those temp readings are 180 for the lower and 120 for the upper, then the kit probably wouldn't help much to be honest. The kit would definitely lower the temps some more, but maybe not enough to make a 5hp difference. Also, I don't know HOW they took those temp readings. They could be different than my readings.

I still want to get my hands on a test vehicle to be certain! I'm not ready to give up on the 4th gen guys yet.

MikeSDA

iTrader: (23)

depending on price Id probably be in, these generally work on anything, just some better than others

trialt

im also interested. if the price is right.

hacim105

iTrader: (6)

The problem is we have no test vehicle. So I don't think anything is going to come about with this.