LX9 vs 3400 intake

[ericjon262]

does the throttle body flange on both intake point in the same direction, at the same angle? I'm running into a clearance issue, I'll see about getting some pictures,

[Mars]

Yeah its very close, if not identicle.

I didn't have to redo my intake piping from the TB to intercooler when I went from 3400 to 3500...

[ericjon262]

thanks, looks like I may have to make a new adapter for the LX5 TB...

[ericjon262]

can you post a pick of the later 3500 manifold next to an LX9 manifold? that may be an option for me...

[Kaiju Senso]

Umm why is your throttle body on the accessory side of the motor?

[ericjon262]

it might not be depending on the intercooler setup I go with, but as of right now, it'll be reversed to keep it away from the turbo.

[Kaiju Senso]

Oh right you decided to go Turbo, can't wait to see that put together.

[ericjon262]

what are the thoughts here performance wise, I've heard the 3400 UIM actually flows better than the LX9 manifold, but I've never seen anything to substantiate that claim. it looks as thought velocity would be higher in the 3400 than the open plenum LX9. I'm going to have to modify the intake either way for clearance reasons, so I'd rather get the better performing intake. also, aren't late 3100 and 3400 intakes the same?

the rest of the engine is a stock 3500 with a mild cam, custom headers, and a turbo. the car is a 5 speed 85 Fiero.

Thanks-

Eric

[1988GTU]

For turbo, I'd use the 35 intake. I noticed a difference in how power comes on and carries out between the BP34 and 35 intakes. The 35 had a smoother transition and the car would pull much longer. By longer I refer to the powerband being carried over making it look straighter rather than a mountain/choppy hill.

[ericjon262]

For turbo, I'd use the 35 intake. I noticed a difference in how power comes on and carries out between the BP34 and 35 intakes. The 35 had a smoother transition and the car would pull much longer. By longer I refer to the powerband being carried over making it look straighter rather than a mountain/choppy hill.

10-4, thats what I wanted to know. guess I'll be doing a little grinding and welding on my 3500 intake then.

I almost wanted to use a 3100 intake though, just to underplay the car that much more...

[Fireball]

I had a 3500 intake on my Malibu (3100) for about 6 months.
I was having some drivability problems so I swapped back to my ported 3100 UIM suspecting the 3500 one.

Well it turned out the TCE spacers were causing a giant vac leak on cylinder 3 and small ones on the other cylinders (I should have put UIM gaskets on both ends of the spacer).
I went ahead and put the 3100 one back on..

Notes:
- 3100 = more low end torque up until about 2-3k... for drivability it is nice to have that on the highway (think it's a higher air velocity thing).
- 3500 = less down low, 3k and up is no contest, even unported. I have lots a significant amount of kick on the highway or even accelerating in 2nd.

I'm really wanting to go back to the 3500 one now... I figured the ported 3100 would have as much or more kick given that it has no vac leaks.

I think both intake mani's have their ups and downs, it's just a matter of what you're looking for!

[ericjon262]

what spacers were you running? phenolic or alumium?

[Fireball]

what spacers were you running? phenolic or alumium?

Phenolic ones.

[ericjon262]

Phenolic ones.

the phenolic material isn't very consistent, that's why I opted for aluminum.

[Fireball]

the phenolic material isn't very consistent, that's why I opted for aluminum.

Wonder if double gasketing it will do the trick?
It's such a pain to go back and forth from setup to setup though...