Intake manifold

**concealer404** · 6-29-09, 8:51

Just a couple questions about it.... i searched for the info i was looking, but didn't come up with a whole lot.

Anyways.... i was working on the car again last night, doing general tune up stuff and tracking down an oil leak. I got stuck, and spent about 5 minutes blankly staring at the intake manifold, and realized that it looked very much like the manifold on my Celica. Which.... is a horrible piece of engineering.

So, i have two scenarios for improving it, and would like comments, thoughts, info on both.

1) Port matching/extrude honing. I can port match it to both the head and the throttle body myself, and i can get it extrude honed for cheap. Is this even worth doing? What gains could i expect, if any?

2) Is there aftermarket solutions available that don't cost the same as two months of a mortgage? With the Celica, we have a vendor that will hone the runners, and attach a better tank on there for under $500, dyno proven for almost 20whp, and give a much more even flow across the runners.

I have the same questions for the exhaust manifold as well. I know i'm a pain.

**GinsbachC** · 6-29-09, 9:19

That would be nice to have a good power gain like that! I did a little port and polish on my head and got some difference. What are you using for porting tools? Obviously a die grinder but any special bits?

**concealer404** · 6-29-09, 9:34

Quote:

Originally Posted by GinsbachC

That would be nice to have a good power gain like that! I did a little port and polish on my head and got some difference. What are you using for porting tools? Obviously a die grinder but any special bits?

I'd love to do my head, but it's only got 7000 miles on it. I'd feel better about messing with a spare head or something, and i don't have one yet.

I'm just using standard grinding bits to take off the material, then a bunch of man hours to smooth out the scratches and irregularities by hand. I don't even know if this motor would even really benefit, just bouncing a cheap idea around in my head. I got a small difference on the butt dyno of the Celica doing it, and i'm no pro at this, and that's just a weak n/a Camry motor. I'd be inclined to believe that the gains on the F2t could be more. (If it's even necessary, it might line up perfectly already, i don't really know.

**ls six** · 6-29-09, 11:01

DIY ITB's with a fabbed tank connected to the charge pipe

**concealer404** · 6-29-09, 12:48

Quote:

Originally Posted by ls six

DIY ITB's with a fabbed tank connected to the charge pipe

That's a bit extreme for something that i drive daily.

Would be awesome, though.

**GinsbachC** · 6-29-09, 14:23

I have got about 65 hours in my head. I think it is well worth it though! I only removed half of the material you can. But as for the comment "it might line up perfectly already, i don't really know" it doesnt... even after removing around 1 1/4 cups of metal there is still a 1/8 ring around both intake and exhaust! I have a spare head and a spare block. I want to max the port and polish and bore the block over. I would like to see if I cant make it a 2.4ltr if possible...

**mx_masta** · 6-29-09, 14:34

My vote's for a fabricated upper manifold attached to the factory lower (ported and matched)

I'd go for bellmouthed runners about 1/2" shorter than standard with a much larger plenum volume.

Bellmouthed runners are a given otherwise you might as well not bother.

1/2" shorter runners to move the resonant rpm frequency up in the range.

And a larger plenum to try and ensure equal charge density to each runner.
You could try a tapered plenum but if the plenum volume is large enough then it won't matter much.

**GinsbachC** · 6-29-09, 17:47

fabricating your own would be a hell of a thing to see! Essentially you could rid yourself of the EGR ports as well. Or i have atleast.

**ls six** · 6-29-09, 18:01

Quote:

Originally Posted by concealer404

That's a bit extreme for something that i drive daily.

Would be awesome, though.

You can buy EFI ITB's for $50 all day on ebay so the cost is minimal. If you have the tools and skill to make a new manifold then you can easily change to ITB's.

Despite the fact that you usualy see ITB's on high RPM race motors they are great for making low end torque and broadening the torque and power curves.

**gavin** · 6-29-09, 21:21

http://www.mx6.com/forums/1g-mx6-for...e-project.html (High Flow Intake Project)
http://www.mx6.com/forums/2139568-post20.html

ls six... ITBs on full race motors are just that...fully built from the ground race motors built with a plan to have ITBs. Thats a far cry from a daily driven engine. From the folks who do have ITBs on street driven cars they all seem to be agreed that they are a royal PITA to keep well tuned. Can it be done? Sure, but its not as plug and play as you make it seem.

Gavin

**Zach** · 6-29-09, 22:49

Quote:

Originally Posted by gavin

http://www.mx6.com/forums/1g-mx6-for...e-project.html (High Flow Intake Project)
http://www.mx6.com/forums/2139568-post20.html

ls six... ITBs on full race motors are just that...fully built from the ground race motors built with a plan to have ITBs. Thats a far cry from a daily driven engine. From the folks who do have ITBs on street driven cars they all seem to be agreed that they are a royal PITA to keep well tuned. Can it be done? Sure, but its not as plug and play as you make it seem.

Gavin

Even the dual or triple mikuni setups of the old datsuns were a pain in the ass to keep running correctly. But once tuned right, and when they stayed in tune, boy there's nothing like it.

**concealer404** · 6-30-09, 5:44

Quote:

Originally Posted by gavin

http://www.mx6.com/forums/1g-mx6-for...e-project.html (High Flow Intake Project)
http://www.mx6.com/forums/2139568-post20.html

ls six... ITBs on full race motors are just that...fully built from the ground race motors built with a plan to have ITBs. Thats a far cry from a daily driven engine. From the folks who do have ITBs on street driven cars they all seem to be agreed that they are a royal PITA to keep well tuned. Can it be done? Sure, but its not as plug and play as you make it seem.

Gavin

Yeah, this is why i'm not doing ITBs.... I had a 2nd gen Integra with ITBs a few years back, and it was hell on the street. Sounded and ran GREAT. When it wanted to.

In terms of me making my own custom manifold, about the limit of my skills would be to possibly put a new plenum on the existing runners. I'm not really all that good. I can port and polish the existing stuff, though. This thread has given me quite a few ideas, too. I'm going to try to score a spare manifold, and hopefully head in the next week or so and get to work.

**GinsbachC** · 6-30-09, 8:24

where do you live?

**concealer404** · 6-30-09, 9:19

Quote:

Originally Posted by GinsbachC

where do you live?

Indianapolis

**ls six** · 6-30-09, 18:11

Quote:

Originally Posted by gavin

http://www.mx6.com/forums/1g-mx6-for...e-project.html (High Flow Intake Project)
http://www.mx6.com/forums/2139568-post20.html

ls six... ITBs on full race motors are just that...fully built from the ground race motors built with a plan to have ITBs. Thats a far cry from a daily driven engine. From the folks who do have ITBs on street driven cars they all seem to be agreed that they are a royal PITA to keep well tuned. Can it be done? Sure, but its not as plug and play as you make it seem.

Gavin

That first link had nothing to do with ITB's

If the people you are talking to cant tune a car to run on ITB's even better than the same setup on a single TB with plenum then you need to start hanging out with smarter people lol.

What exactly is difficult about tuning ITB's?

As for ITB's only being on motors designed from the first to work with ITB's you have obviously not heard of the Nissan Skyline GT-R or the Nissan GTiR. Both street cars and both quite deserving of their reputations as awesome STREET cars.

Both use ITB's on motors originaly (and most commonly) equiped with single TB's.

Both used turbos no less.

And I dont hear about the motorbike community having any real difficulty with ITB's.

I do plan on installing ITB's onto my 2G eventualy and since it has been done before and without any great hassle I dont think I'll regret it.