1bad91Z

iTrader: (1)

Yea, it's a 1985 Lamborghini Countach motor, but it's still TPI and cool looking!

boldguy

almost like an LT5

F-Body Demon

iTrader: (1)

Dig the dual intake on both sides of the plenum...very nice.

avro206

that is not TPI at all

1bad91Z

iTrader: (1)

Equal length tuned intake ports upto the plenum..... I call that TPI.

Stephen

iTrader: (12)

Well, that depends on the definition...

Is it TPI? As in, 84-92 Chevrolet engines? NO
But is it a tuned port & fuel injected engine? Yes.

avro206

so every single port injected engine that meets that def is TPI? What about 2.8L FI engines....were they TPI too?

boldguy

i am pretty sure thats not what he said at all
he said "Equal Length Runners".
so the 2.8s would be called PI's or Pie haha

1bad91Z

iTrader: (1)

By all means, please correct me if I'm wrong, but the 2.8's would actually be classified as MPFI (Multi-port fuel injection)...

avro206

yeah....but ya know--they have equal length intake runners...must be TPI too!!

gmgod

Actually, I think they do have tuned length runners.

ls six

So dose my mazda come to think of it! It has the variable resonance induction system as well so that makes it VRISTPI.


Most modern engines use equal legnth runners and lots of older motors do too.

And dispite all the marketing hype surrounding the TPI's back in the day all motors use intake runner tuning to determine the output of the motors.
Even if it isnt the primary concern of the design the runners allways affect the power/torque curves.

1bad91Z

iTrader: (1)

Well, there is a reason that GM named the 2.8/3.1's MPFI and not TPI (besides marketing). GM also named the 96-98 Chevy truck vortec 350's (CPI) or central port injection.

So I guess this poses a question......

What exactly characterizes an intake manifold as (Tuned Port Injection)?

On a side note:
The lambo TPI intake is pretty cool with the two throttle body design! Notice the size of the runner tubes are pretty close to the runner tubes of a stock chevy TPI. What makes this interesting is the lambo cylinders are way smaller (the above motor is only a 4.8 liter even though it is a 12 cylinder) and it still has TPI size runners or slightly larger with 2 throttle bodies.

Just goes to show you the benefit of bigger runners/throttle body/lower intake manifold even on a stock motor.

Abubaca

iTrader: (3)

Around here, Tuned Port Injection refers to the 85-92 LB9 and L98 engine intake manifolds. While the definition may lend itself to many engines worldwide, they're not refered to as "TPI".

Look at it this way: All cakes are made in pans, right? But I've never had a "pancake" for my birthday, ya know?

IROCtheThird

iTrader: (15)

I think everyone is missing the point. Yes alot of old/modern vehicles use runners of equal length, but in Tuned Port the runners are "tuned" (hence the name) to a specific length for a certain performance quality (****loads of low end torque on the LB9/L98's). Yes Chevy dubbed the name "Tuned Port Injection" but there is many variances that are similar. And for the record the MPFI on the 2.8/3.1 f-bodys was also a tuned runner system. If you note to some GM manuals they even refer to it as "TPI". Just my

Abubaca

iTrader: (3)

OK, whatever. You put a carb spacer under you carb, and technically you've "tuned" it. It IS in fact a "port", and you could argue that the jets are under pressure and they "inject" fuel. That's not really too far of a stretch.

From here on out, all cars ever made with gasoline engines are "TPI". Forget what I said about 85-92 F bods with L98 and Lb9s. I've been corrected.

.......or we can stop splitting hairs on technicalities and call TPIs what they are. LB9 and L98 engine EFI intakes.

ls six

As I said all motors use tuned legnth runners as runner legnth is a critical component in determining the out put and character of the motor.

Older carbed motors typicaly had short runners and if they were performance oriented they naturaly made peak power high on the tach.

So called "tuned" intakes only became practical with the introduction of port injection since long runners on a wet intake tend to suffer at lower RPM because of fuel falling out of the air. That kinda cancels out the low end benifits of long runners.

cwyates4

iTrader: (1)

You are trying to make TPI a classification. I believe the tpi is already classified a MPFI.

IROCtheThird

iTrader: (15)

I give up, I thought ford people were ***holes, all I'm trying to say is dont chop someones head off for calling another car companys set-up similar to tuned port.

You dont need to be a ****head about it, I just dont see why people have to get argued with when the original post was just lookin at a cool induction set up.

igotta355z28

iTrader: (1)

ok as said b4 TPI is not a classification its a name. TPI IS MPFI.....just like Posi traction is a LSD....Chevys special name for it nothing else....I dont know of any intake manifold where the runners were just made with no planning and adjustments there for like said before intake manifoldss are all tuned....