[ThUmPeRcOn]

Originally Posted by breckboarder55

I would be happy to dyno test this on my 2.5 if someone wants to send me the part... I would even send it back if they wish...

We need someone to Dyno this thing Does anyone have one laying around or in a tool box they could send "breckboarder55" so we can see a true dyno result and put this to rest: Hold on bretborder55 someone who has one will surly chime in and want to see.

[Jerry Bransford]

The problem with dynos is you need a disinterested party to run the tests. It's very hard to run a dyno properly so the RPMs and other conditions are exactly the same between tests. One "dyno" test that was around the Jeep forums years ago showed higher HP from some gizmo. Unfortunately for the company pushing their product, you could also vaguely see the RPMs in the background were slightly higher on the dyno that showed the slightly higher HP on the product they were pushing.

[ThUmPeRcOn]

Originally Posted by Jerry Bransford

The problem with dynos is you need a disinterested party to run the tests. It's very hard to run a dyno properly so the RPMs and other conditions are exactly the same between tests. One "dyno" test that was around the Jeep forums years ago showed higher HP from some gizmo. Unfortunately for the company pushing their product, you could also vaguely see the RPMs in the background were slightly higher on the dyno that showed the slightly higher HP on the product they were pushing.

Well now I wonder how many manufacturers/products do the same? Oh well as usual thank you, Jerry And when I bought my '00 TJ it had one on it my fiance use to break into the chitty, chitty bang bang song every time I got 50-55 mph and it would whistle I gave it away it scared every deer off for a mile when my buddies and I were archery hunting we had to climb a big hill to get to where we were allowed to park, that thing would suck, whistle it seriously freaked the deer out. Hey I think I just came out a better marketing solution for it Get one today "THE SUCK & WHISTLE DEER DETERRENT by:Airraid

[Unlimited04]

Originally Posted by ThUmPeRcOn

Well now I wonder how many manufacturers/products do the same?

HP from most auto manufacturers is SAE certified, you may notice this note on their literature. This is important for some manufacturers, because they believe certain cars will sell better with this rating, like sports cars or tow vehicles. They must pay extra to get this SAE stamp, so not all engines have it.

SAE (Society of Automotive Engineers) developed engineering standards J245 and J1995 of how engines are to be tested. An SAE person is on site whenever these tests are run to verify accurate results.
http://en.wikipedia.org/wiki/Horsepower#SAE-certified_horsepower

For aftermarket stuff, you show me some SAE certified results showing 25% increase in horsepower and torque due to XXXXX mod, and I'm there with cash in hand.

This is why dyno results typically show a 'before' run and an 'after' run, because of the uncertainty resulting from drivetrain loss and other variables introduced by a non-SAE test. As Jerry pointed out, watch the RPMs and assumed drivetrain loss numbers closely, because lots of fudging can be done here. If you see a dyno of a 4.0L @ 6000rpm, well its worthless because redline is 5000rpm. Also notice most dyno charts start at 3500rpm...but how often does your 4.0L see 3500rpm?

[jgorm]

I may be the man for the job. If all my plans go well i should be buying a dyno from Alabama and shipping it back to san diego in a couple weeks. I will do scientific unbiased tests on some of this stuff to see what the real deal is. I have no affiliation with any jeep companies and will actually be using the dyno mostly for ford tuning. The results will probably be in the form of -- average of 3 pulls, do the part swap, then average of 3 pulls. I'll start the pulls from 1000rpms so we can get some numbers for the low rpms too. I just need to find an easy way to hook up the spark meter. My jeep has that giant coil block with no wires exposed.

[NikVallens]

Originally Posted by Jerry Bransford

Sez who, someone's friend who knows someone whose uncle had a buddy who saw the dyno results?

something along those lines

[McCall]

I'm tending to see a "consensus" of most people here (which may or may not be right just because everyone says it is) on this forum that spacers and even cold-air intakes are worthless on 4.0 liter motors. While I agree for the most part that at lot of aftermarket performance parts probably don't do that much vs. $$ spent, I did find this older review of a K&N cold-air kit by Off-Road Adventures Magazine. They did their own separate test and verified the manufactures’ claims about 11-12 rwhp.

http://www.oramagazine.com/pastissues/0508-issue/050801t-rubicon.html

Not a bad mod if you ask me for the money. Now a spacer might not make a difference but until I see actual dyno results I'm reserve my judgement. Bench racing via internet engineering should be held to a minimum IMHO.

[plowe]

This guy has been sucking to many gas fumes. Trust us - spacers are junk!, and if you put a snorkel on your jeep, your mileage will actually decrease, unless its 4" in diameter. snorkels work to keep water out o the engine, thats all.

[NaeKid]

Filled up again last night. My little yellow idiot light turned on at 428km and I filled up shortly after at 433km. I took in 57.2 liter of gas.

21.38 Miles / CadGallon
15.11 Miles / USGallon
13.21 liters / 100km

If this continues to be the average, I only need 5 more tanks of gas to recoup the price that I paid for the spacer, then, I'll be saving money. I haven't really changed my driving style, or the places that I drive. 90% is from home to work and back again. The other 10% is errand-running or going out to visit friends.

[brass]

I bought the one for $25 listed in this thread
http://reviews.jeepforum.com/showproduct.php?product=233&cat=18

It was a little rough but I hit it with a polishing wheel and cleaned it up. Probably didn't need it but - you know

Anyway, I figured for $25 - whatever. Anyway - when all is said and done with a CAI + exhaust + spacer there was a gain in MPG plus some extra power that's slightly noticable in all gears.

Was it worth it?

Probably not. I am going to start saving for a crate stroker if I want to go for HP. For now, I have enough other crap I need to really start saving for - axles, lockers, wheels and tires to start. Then, say buh bye to any "performance" gains made by the above mods.

The only good news is that maybe by adding the K&N is that it will reduce my stock engine life and force me to buy a crate stroker

[Jerry Bransford]

There's no rational reason why a TB spacer would improve fuel economy. If it did, why wouldn't Jeep (and all the other automotive manufacturers) do the same simple inexpensive thing, especially since they are under enormous state and federal pressure to improve their CAFE (fleet) fuel economy numbers. I believe there's a subtle subliminal subconscious effect going on here to somehow show better gas mileage after installing that thing.

[Squeeky]

Originally Posted by WillysEdition04

So far the only engine bolt-on's that seem to have had positive results are the Trail Jammer kits from Edge...

...and the only reason that does any good is because of the performance module. I have one and I got no increase until I used my performance tuner. (I didn't get the performance module cause I have a tuner for the 04 wranlger)

[djt283]

Putting aside the fact that there's no possible way a TB spacer could possibly change anything...you do realize that keeping track of a few tanks of gas is a useless comparison, right? Also putting aside the fact that the OP believes this is working (so his tests don't count), you'd have to average gas usage over a very long period of time (like a year before and after mod) to end up with anything approaching scientific data. Just think of all of the different driving conditions, moods of the driver, road surfaces, etc for each "400 km" tank. Not to mention you're assuming each fill is to the exact same point and the gas is exactly the same and the weather is the same, etc...

Don't even know why I read these threads now that I think about it.

By the way, the original pics and write-up were nice.

[djt283]

Originally Posted by Jerry Bransford

I believe there's a subtle subliminal subconscious effect going on here to somehow show better gas mileage after installing that thing.

Granted, Jerry is usually right, but this is exactly my opinion as well. If anyone here has ever done any work with placebo tests or studied even basic psychology, you should see the same thing. Part of testing for new drugs is as compared to a placebo...problem is so many people now they are being tested and convince themselves they have side effects that even that doesn't work.

I'm going to start convincing myself that I make twice what I do and maybe that will come true as well.

Edit: I paid $3.95 a gallon today...if there was even a remote chance this could do anything, I'd buy it. Just think about what you're changing...nothing I can think of.

[cheapjeep06]

Originally Posted by Jerry Bransford

In all deference to NaeKid and what he feels he has experienced with his, my opinion is that it's more of a placebo effect than anything. There's no technical reason a TB spacer will add anything to low-end torque.

My 2001 Ford explorer with a 4.0L v-6 has a 2-path intake...longer used until around 3500rpm, i think, to increase low end torque, then switches to shorter for high-end gain. This is also multi-point injection. Are Ford engineers wrong? (Gotta play devil's advocate.)