Intake Manifold - Mag or Ghettoblaster?

rmc03 · Post by **rmc03** » Wed Jul 14, 2010 3:14 am

Hey guys, I've just recently got back into things & I've been searching around a ton looking for more information on the mag intake mani vs. a homemade setup from a 1gn mani.

I'd like some input on which would yield better power in the 4-6500RPM range and still be street friendly. I'm planning on pairing the intake manifold with a longtube header/straight through cat back. I'm unsure if a larger throttle body (>52mm) would be of interest or not really worth it for my setup.

I would also like to find more information with pics on building the "ghettoblaster" intake manifold. I've searched around and haven't really been able to find any solid how-to's on them. If someone could point me in the right direction I'd greatly appreciate it. Thanks guys

Post by **occasional demons** » Wed Jul 14, 2010 11:04 pm

Even tho I like my GBI, I think the factory Magnum IM will make more power. The GBI still has stock runners, and most are cut shorter, where they are a smaller inlet diameter.

I think mine is a bit different than most, as I have the 60mm TB mounted directly to the IM. No necked down inlet. I can't say power under 3000 rpm is any better than the 2gn Plastic IM, but above that it gives a good butt dyno result. If I ever get around to swapping the Mag IM on, (with the 60mm) I will have something to compare.

rmc03 · Post by **rmc03** » Thu Jul 15, 2010 1:45 am

Thanks for you input, I've read at other forums that the gains can be pretty decent when paired with other performance upgrades.

I was able to find some more information on building them & I'll be giving it a shot soon.

I'm just a little unclear on a few things & would be thrilled if someone could give me some pointers:

- what sensors/fittings need to be mounted to the plenum as well as the best placement for them.
- how to reduce the 3" plenum down to the intake piping spacer between the intake mani & TB
- fitment questions with a CAI, isn't the open side of the plenum now much higher when it is bolted on?
-everyone mentions removing injector humps, what are they?

BlackRoseRacing · Post by **BlackRoseRacing** » Sat Jul 17, 2010 10:32 am

viewtopic.php?t=12037&highlight=ghetto+blaster+intake

Post by **occasional demons** » Mon Jul 19, 2010 9:57 am

rmc03 wrote: I've read at other forums that the gains can be pretty decent when paired with other performance upgrades.
I'm just a little unclear on a few things & would be thrilled if someone could give me some pointers:

- what sensors/fittings need to be mounted to the plenum as well as the best placement for them.

The MAP sensor should be mounted to the IM for the most direct input, tho many of the older cars had the map sensors remotely mounted, connected via a vacuum line. You will also need the large vacuum nipple for the brake booster. You could tee off of that if you don't wish to tap any more vacuum nipples. I even have my IAC/PCV tee'd into that line.

- how to reduce the 3" plenum down to the intake piping spacer between the intake mani & TB

Well back to "paired with other performance upgrades"
My GBI didn't really act any differently with the oem TB/pipng than it did with the oem IM. Either glue a flange in the tubing to direct mount the TB (Ford) or glue in a piece of AutoZone/Spectre tubing, and adapt to that for a MP/Lorenzo TB. Having a direct 63mm inlet into the IM is where you will see some improvement.

- fitment questions with a CAI, isn't the open side of the plenum now much higher when it is bolted on?

Yes, tho the difference depends on how much of the runners you cut, and there is no angle, unless you glue in a bend. (Again Spectre)

-everyone mentions removing injector humps, what are they?

Injector humps are the ramp that smooths out the air flow around the injector. It would be a lot of extra work for a GB. The indent you see in the top of the runners right before the injectors is the "hump" you would need to glue a pice of ABS over the hole you make to remove that. I doubt the HP gain would be worth the effort. It's not like these can be ported extensively.

rmc03 · Post by **rmc03** » Tue Jul 20, 2010 12:03 am

wow thank you for the info, you're going to hate me after typing all that when i found something today haha

so stoked!

blueneo03 · Post by **blueneo03** » Tue Jul 20, 2010 1:06 am

i hate you for getting one... i want!!

Post by **occasional demons** » Tue Jul 20, 2010 7:13 am

It's information someone can use, so not a total loss. Gratz on the IM!

The inlet on that can be ported out to 56-58mm depending on the wall thickness.

rmc03 · Post by **rmc03** » Tue Jul 20, 2010 9:25 pm

I was throwing around some measurements and I think i'm definitely gonna have to port the inlet a bit, it looks like it can go another 2mm safely the whole way around

I pulled the plenum piece apart from the runners and noticed a lot of casting imperfections on the insides and other rougher spots that need to go. I'd like to also gasket match it.

Should I smooth out the inside as much as I can?

stdlystdmufn · Post by **stdlystdmufn** » Tue Jul 20, 2010 9:34 pm

yep do it! you don't have to worry about polishing an IM too much when you polish the stuff before the fuel. (in other words the plenum is good to polish) but if im wrong then OD or anyone else smarter than me will give you a better answer.

Post by **occasional demons** » Tue Jul 20, 2010 11:31 pm

Meh, The way I see it, the inlet and runners are more important than the plenum chamber. It's not like there is much velocity in the plenum compared to the runners. It is mainly there for a reservoir to pull air from, and absorb the intake pulses. You just need to fill and empty the reservoir as efficiently as possible.

I would smooth the inlet area, and the runners. You could gasket match the flange where it mates to the head, but it won't do a lot until you gasket match the intake ports on the head. Cleaning up the underside of the inlet for the runners would be a PITA, unless you have some special tools, and a mirror to see what you are doing. It would have made that part easier, if the MTV section was a separate piece from the plenum. But I guess we should be grateful they even made a performance IM for the neon.

blue demon02 · Post by **blue demon02** » Thu Jul 22, 2010 11:10 am

You know i think i am going to make another ghetto blaster and make it so my buddy Arthur can dyno it on his beast for his next 2.4 project. Going to have to use a 2nd gen one so i can make the flange super thick so i can make the ports big enough to mount to his head.

Now that i'm sitting here thinking about it i bet i could make a one with working secondaries. h,mmmmmm.

rmc03 · Post by **rmc03** » Thu Jul 22, 2010 11:01 pm

I had a moment this evening to clean it up a bit, still messy but I think I can live with a shiney/rough surface for now

SlvrACR · Post by **SlvrACR** » Thu Jul 22, 2010 11:13 pm

Get it ceramic coated in chrome

Neon4Life · Post by **Neon4Life** » Thu Jul 22, 2010 11:21 pm

^ nice.

not to throw the topic off hand but how much does something like that cost..?

SlvrACR · Post by **SlvrACR** » Thu Jul 22, 2010 11:23 pm

Depends on the shop really. I get a deal on my stuff so i really dont know. Thats why I PC everything lol

blueneo03 · Post by **blueneo03** » Fri Jul 23, 2010 12:07 am

take some time on it and polish it... imo looks better but tons more work

rmc03 · Post by **rmc03** » Fri Jul 23, 2010 12:08 am

that's gorgeous, powder coating it may be an option in the future after seeing how nice that came out, I've still got a lot of work ahead of me cleaning up the casting imperfections etc.

stdlystdmufn · Post by **stdlystdmufn** » Fri Jul 23, 2010 11:46 am

what ever you do do it now while its not on the car because you wont want to take it off to do it later. not that its hard to take it off just that you won't want to be w/o it.

rmc03 · Post by **rmc03** » Fri Jul 23, 2010 12:37 pm

stdlystdmufn, i was looking over your pictures and noticed you got your cold air intake to fit nicely. what's the angle pipe that's connected to the inlet of the mag manifold? just a cut down 45?

stdlystdmufn · Post by **stdlystdmufn** » Fri Jul 23, 2010 2:01 pm

well i needed a CAI anyway so i just bought one for an r/t but if you wanted to make one i don't think it is quite 45*

found a write up here

Post by **occasional demons** » Fri Jul 23, 2010 2:15 pm

Click > 22º intake tube 2.5"

Edit:

http://www.spectreperformance.com/#CATALOG.9229

rmc03 · Post by **rmc03** » Fri Jul 23, 2010 11:45 pm

you guys are awesome, thank you for the help!

is a headpipe/cai/mag intake going to make my car run lean? i was curious where the point is that the injectors need upgraded

gtxtreme19 · Post by **gtxtreme19** » Sat Jul 24, 2010 1:52 am

That point is some sort of forced induction... any bolt-on will not make your car run lean or rich. Go for it

Post by **occasional demons** » Sat Jul 24, 2010 7:01 am

The stock injectors will support just about anything you can throw at them, except boost, and 100% E85.

rmc03 · Post by **rmc03** » Fri Jul 30, 2010 4:39 pm

Here's an update - I decided to start polishing but my godddd it takes forever!

I still need to smooth it off a bit where the 4 casting marks are (the light kinda hides them) but I think it'll be worth it once I put a few more hours into it.

*edit*
just finished up with the 100 grit, nearly all pitting is gone and casting marks are smooth as glass! she should polish up real nice now as i step the grits up

*edit 2*
finished up through 300ish grit, wooo!

2GN.ORG

Intake Manifold - Mag or Ghettoblaster?

Intake Manifold - Mag or Ghettoblaster?

Hmmm

Re: Hmmm

thanks!