[LoopOut]

Ok. I've been reading alot lately of guys trying to get an intake manifold spacer made for our trucks. This got me to thinking...

If I had an extra intake manifold sitting around from a motor change, I wonder if it is possible, that I could maybe just cut the tubes/runners off the mounting base plate of the spare and use that as a spacer????? I think it would be close to the same thing. Just might not be as thick as an actual IMS would be, and not aluminum.

Commence brainstorming.

 

[2WD_NISMO]

Yep. A guy in a Z forum made his out of MDF (?) plywood (a finished/smooth type of plywood ).

 

[rcr_kx250f]

for the time and energy to do it, you can use your uprev to advance timing 2* and have a much bigger difference.

 

[LoopOut]

2wdNismo: Yeah I guess eh? It doesn't see any moisture so I guess wood wouldn't be that bad. Not my first choice, but...

RCR kx250f: I will be advancing my timing. Im just waiting for some decent weather around me to do some tinkering and datalogging. Are you suggesting that IMS are kinda useless then??? Seemed alot of people were pumped about the idea, so figured it may be worth the effort, but I don't know.

Keep the brainstorming goin boys.

 

[rcr_kx250f]

in theory, because the intake run is longer, the air will move faster. however, it's such a small change, it doesn't make a noticeable difference. the only real reason is if you're adding nos or other ridiculousness. There is no such thing has easy power gains...unless you're playing with the computer, and even for that the guys had uprev had to do some serious work.

 

[2WD_NISMO]

The IMS DOES make a noticeable difference, but on the other hand the 2° advance did absolutely nothing for me. In my experience of course.

 

[colin123]

actually basically what your doing with this spacer is changing the tuning of the intake itself by lengthening the runners. basic rules when dealing with intakes is that shorter runners make more power top end longer runners make more power in the low end. this is why car companies from time to time have made come of those complex dual runner intakes you you find on the old for SHO and the JDM cyclone 4g63 that people often swap into there eclipses/talons. these intakes have both a set of long runners for making good power down low and short ones for better power up top than you could make with the long ones and butterfly valves that switch between the two. so when you add this spacer you lengthen your runners and change the intake tuning to slightly shift the powerband. you'll add more low end torque and slightly alter your power top end. a good book to read to get a good understanding of intake and exhaust tuning is Scientific Design of Exhaust & Intake Systems by philip h smith (FIMechE MSAE) and john c morrison (BSc PhD MIMechE) i've read through it atleast 3 times and learn more everytime.

 

[LoopOut]

HMMMMMMM. Well now I don't know if I wanna chop up a perfectly good intake mani just to find out it did next to nothing. Im not against the small mods, that aren't totally noticeable, as I believe a bunch of small mods can make a difference. I did get a chance to advance my timing on saturday, I don't think I noticed anything. If I did, it was just that it smoothed out the power a little. But really no noticeable change. Guess I'll just wait to see what happens after this round of IMS discussions going on, on the forum. Maybe someone will come up with something and some dyno numbers.

I really hate non-dyno proven part results. Nobody's butt is the same and it leaves too much room for opinion.

 

[NCFronty]

From I where I am it seems like a decent gain to me. I have one, and I can definitly feel the difference.

"hp peak [email protected]
torque peak 23ft/[email protected]
more important is mid range numbers
hp from 3600-4800 is 23hp increase
torque 3600-4400 is 33-23ft/lbs increase over previous run."

 

[rcr_kx250f]

2* advace takes time to have an effect. The ecu has to relearn some stuff to match it. I wouldn't cut up a good intake, it would be really long enough to do what the spacers do.

 

[BRUTAL]

ive said for years to make one from plastic or wood. we've done that on V8's for years for carb spacers. Just use your intake as a template and cut it out, cut gaskets and get longer bolts....theyve already been proven to work, much better than the 2* bump, and Ive done both

 

[LoopOut]

Ok. Since RDFronty provided dyno numbers, and since Brutal is pretty much the motor guru round here (not the only one, I know!), im gona do it. Might take some time before it's done. But atleast I already have a spare manifold, removed from a motor. I think seeing as how it doesn't seem to matter, and I have access to lots of MDF (wood) in various sizes, that's the route im gona go. Unless there are objections!

My questions to NCFronty or Brutal as you guys have "done-it" experience:

1) Is wood really a valid idea? What about moisture concerns, like swelling of MDF?

2) How thick should it be? Im sure there's a limit, but I don't even know where to start.

Thankyou all brainstormers. The sooner you teach me, the sooner I can get one of these babies fired off.

 

[NCFronty]

I really can't answer as to using wood. Brutal has done this and says it works fine. I have an aluminum one and it is 1/2" thick.

 

[BRUTAL]

I personally woodnt(pun intended) use MDF, do to moisture swelling issue. we always used quality plywood. The heigth is only limited by the hood and effectiveness of increased power production. once you go over the heigth of the original design you need to extend or add to the manifold support on the side. No one has ever done dyno test of larger spacers. personally if I was doing this. I would make 2 spacers. First dyno with none, then add 1, dyno again, then add the other one for 2 and dyno again. see what changes you get.

 

[LoopOut]

I don't remember who said it, but someone in this thread responded that cutting the mounting plate/flange off a spare int mani would be useless cause it would not be much taller/difference. Well, if NCFronty says his IMS is like 1/2" thick. The stock mani flange is way thicker, I willing to bet I could get a 1" spacer by cutting it off.

NCFRonty: 1/2" eh? HMMM, I wonder if a 1" spacer would be possible or worthwhile venture.

Brutal: Ok, I will also look into some type of Hard wood then, not MDF. My friends dad is big into furniture making and has some special African hard wood he's been using for a while, so I'll check that out. He uses it for deck/lawn chairs specificaly for moisture reasons, and looks. Unfortunately dyno verifying for me will not be possible. I can't afford what they want for dyno time in my area. Last I heard they want like $150 per pull, unless they like the vehicle you brought! And even at $100, it's not worth it to me, I was just throwing out an idea for a cheap DIY solution. And I just happen to have a spare(dead) motor sitting around that has all the parts on it still. I'll see what I can dig up on dyno prices though.

Thanks guys.

 

[bdhaeh]

Go to a sign shop and see if they have any spare pvc sign board, the brand name is Sintra. It comes in various thicknesses and they might give you some for free, you can laminate it together with regular pvc glue. Or you could order it from ebay, but it's kinda pricey. I use if for fishing lures b/c it is waterproof and durable.

 

[NCFronty]

I don't remember who said it, but someone in this thread responded that cutting the mounting plate/flange off a spare int mani would be useless cause it would not be much taller/difference. Well, if NCFronty says his IMS is like 1/2" thick. The stock mani flange is way thicker, I willing to bet I could get a 1" spacer by cutting it off.

NCFRonty: 1/2" eh? HMMM, I wonder if a 1" spacer would be possible or worthwhile venture.

Brutal: Ok, I will also look into some type of Hard wood then, not MDF. My friends dad is big into furniture making and has some special African hard wood he's been using for a while, so I'll check that out. He uses it for deck/lawn chairs specificaly for moisture reasons, and looks. Unfortunately dyno verifying for me will not be possible. I can't afford what they want for dyno time in my area. Last I heard they want like $150 per pull, unless they like the vehicle you brought! And even at $100, it's not worth it to me, I was just throwing out an idea for a cheap DIY solution. And I just happen to have a spare(dead) motor sitting around that has all the parts on it still. I'll see what I can dig up on dyno prices though.

Thanks guys.

I just took mine out today and finalized my CAD drawings to get some estimates from some more machine shops. The intake manifold is definilty thicker than this spacer, probable twice as thick. 1"

 

[LoopOut]

^^Yeah, right after I made that last post I ran out and checked. Seems like after cutting off the runners, and touching up, there would be probably be somewhere around 7/8" to 15/16" worth of thickness left. Only problem I can see, would be like what was mentioned earlier. Having to modify the intake manifold support bracket to compensate for the rise. I would think clearance to the hood for the motor would not be a problem.

 

[BRUTAL]

LOOP just make a small bracket to span the gap and bolt them together. its not like your gonna support the brooklyn bridge...

 

[LoopOut]

Brutal: that was exactly my thoughts. Didn't really think that the bracket would be a big issue to mod. Was just thinking out loud. LOL.

As for cutting up a stock manifold, I don't think it would work. The runners come off the mounting plate at too much of an angle, would lose too much material by the time I cut the tubes off. Tough to describe, but.... picture a 1" thick flange/plate, then instead of the runners coming off the top of this plate, they kind of come out the side.

I'll take some pics when I get a chance just so people can see what I mean. If anyone cares!