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Discussion Starter · #1 ·
I have read a lot of stuff on phenolic spacers and I have seen the "dyno" charts, but do they really work? For the I4, the gains looked great, but were a little unbelievable. If anyone has used them, I would appreciate some feedback.
 

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You do not "gain" anything from phenolic spacers.

They act as insulator, so in effect the prevent the "loss" of power, which in the automotive world is the same as gains. The IM will usually heat up after a period of driving, causing the air inside to heat up and the mixture of fuel to richen slightly making a bit less power. The Phenolic keeps the IM cool and helps keep heat out of the IM. If you dyno back to back on a cool enegine it doesn't do anything. But after awhile it does have a noticable effect. The KL's I've driven with phenolic seems to pull harder top end after about 30 minutes of driving than the ones without.

That being said, even the cooling effect on the IM has it's draw back. Since the heads and block is not able to dissipate heat through the IM it might cause trouble somewhere along the line. Again all of this is very minute and never been proven or disprove, so far everything about phenolic are theories and counter theories.
 
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Discussion Starter · #3 ·
I see. It never really made sense to me how air rushing into the IM at high speed is going to have enough time to heat up in the split second it is in the IM and make a horrendous difference in engine performance.
 

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The tests I have seen show a little gain down low, and nothing up high. This makes sense as down low the air has time to heat up cos it is going slower. Up higher it is going through so damn fast it doesn't have time to heat up.
 

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Baja Wes said:
The tests I have seen show a little gain down low, and nothing up high. This makes sense as down low the air has time to heat up cos it is going slower. Up higher it is going through so damn fast it doesn't have time to heat up.
Couldn't the explanation to this just as easily be pionned on the fact that you have now changed your intake path length?
 

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Yah, definately question the intake lenght.

The Phenolics are like a good 1/4" higher than stock, consider that this is after the runners it's a big big gain. Not to mention the injectors are now squirting into a longer injector port allowing "maybe" a better mix.
 

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I don’t know .. probably not but with out a doubt they do keep the inlet cooler.. and with the ZE you have to use something for gaskets(KLZE gaskets are not so easy to come by)
 

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Mr. MX6 said:
I don’t know .. probably not but with out a doubt they do keep the inlet cooler.. and with the ZE you have to use something for gaskets(KLZE gaskets are not so easy to come by)
Millenia gaskets work just great on the ZE and you don't need to worry about raising the IM any more on a hood that rubs on it as it is. As for gains, I just don't see it. How long is air in the IM anyway? When you actually drive for power your RPMs are no less then what? Maybe 3K? So at 3000 RPMs per minute, 2.5L engine, we'll say 75% volumetric effieciency. Well, I don't really want to do the math, but frankly I don't see the air being in the IM long enough for it to make any appreciable difference. And let's face it, the IM will heat up anyway. It's just gonna take longer. All that being said, I'd much rather take the money used to keep my intake cool and save it for a cold beverage or 2 to keep me cool.
 

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parisifal said:
Yah, definately question the intake lenght.

The Phenolics are like a good 1/4" higher than stock, consider that this is after the runners it's a big big gain. Not to mention the injectors are now squirting into a longer injector port allowing "maybe" a better mix.

So does this mess with the VRIS points or not? I am guessing it doesnt since it is after the runners, but if someone knows for sure..........
 

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The longer runner length issue has been addressed before, but the addition of a 1/4" length to the runners should shift torque production about 50 RPM to the left on the Mazda KL.

The fuel having a longer mixture time is slightly unfounded as much of the fuel vaporization takes place upon contact with the back of the hot intake valves and the tumbling encountered inside the cylinder prior to ignition. At first we were concerned that the movement of the injection point would negatively affect exhaust emissions, but testing has proven otherwise.

As far as the cooling system being taxed by the thermal separation of the intake manifold, this has been disproved by testing and the evidence of thousands of spacers in the field for years. A stock coolant system has enough excess cooling capacity to cool the engine under the most inhospitable conditions and the coolant temperature simply does not increase after spacer installation. If it does, than you have other more serious problems.

Our own testing does show a greater gain in the lower RPM band versus redline and we also attribute it to charge velocity. Check out the plots from some of the other engines on our website.

Indeed, the ThermoBlok spacers do not make "horrendous" gains, but the gain is there. Outlaw has always made a commitment to never offer a product that does not produce a reasonable gain for the money. In fact during prototyping this summer, some engines such as the Acura B18B and Chrysler 420A did not respond very well to ThermoBloks, but others did. Therefore we will not be offering kits for these engines (although people have been asking) unless we can change the product to make power. We want to stay far, far away from gaining a reputation similar to the company that produces the Tornado.

If thermal insulators are "snake oil", it would seem that Outlaw is in good company. BBK and Edelbrock produce them for american engines. Hondata and Evolution amongst others produce them for imports and even Ford's own SVO offers them for Mustangs. Thermal insulators have been around for decades, just ask any old racer you see at the track, but they are just now receiving growing recognition with the import crowd.
 

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Also, as far as the VRIS points go, the addition of spacers affects the points very minimally. The resonance points, as stated above, move on the order of 50 RPM. Outlaw is considering offering custom ECU chips (EEPROMS) for those that would like to have different VRIS change points, rev limits, etc. Anyone interested?
 

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scmorgan said:
Also, as far as the VRIS points go, the addition of spacers affects the points very minimally. The resonance points, as stated above, move on the order of 50 RPM. Outlaw is considering offering custom ECU chips (EEPROMS) for those that would like to have different VRIS change points, rev limits, etc. Anyone interested?
There's already a few people who have accomplished this as I'm sure you're well aware. If you're gonna jump into reprogramming ECUs from phenos, you should also consider the offering them with the ZE VRIS points as well. I'm sure some of us would love another option in that arena.
 

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Actually, we would probably offer custom revised chips to whatever VRIS points, etc. the customer wanted rather than a one size fits all chip.
 

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Yes, I think the VRTuner is a long overdue product. I also wonder if it can be used as an RPM switch for other applications. Obviously, a chip would not have the VRIS functionality of the tuner, but a chip would be cheaper and include other functions such as custom rev limits and EGR valve operation changes.
 
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