SprintStar

Hello All,

Which would you choose? The intake manifold from SpeedForce Racing or from Lindsey Racing?

I'm in the market for a new turbo and since I have to remove the intake manifold, it might be a good time to replace it.

Or is the stock item good enough?

Thanks!

Sprint.

333pg333

The stock item can be improved upon or even just modified. If you buy an aftermarket intake you need to tune your motor around it to a degree, or at least be prepared to change it's characteristics. If you buy one of those intakes you would probably buy the turbo that they recommend to go with it.
Depends on what you want from your car.

porshhhh951

I like the look of the SFR manifold better. However the stock intake flows plenty for a stock turbo.

evil 944t

Without headwork/cams/etc.. I wouldn't bother. You can't out flow the stock manifold. Just changing the manifold without all the other supporting mods will be a waste of money.

SprintStar

What mods can be done to the stock one? Extrudehone?

Sprint.

porshhhh951

Yes but, without other mods there is no point.

ausgeflippt951

The stock manifold was quite well engineered -- there was a fair bit of flow development done with it. Unless you're throwing hundreds of hp to the ground, I wouldn't bother. Plus, the stock intake looks better IMHO.

blown 944

unless you are planning on larger than a 60mm inducer or swapping turbos weekly I wouldn't even think about it.

TonyG

I had mine cut apart, ported, flowed, and welded back together. Worked very well (in conjunction with the rest of the top end modifications).

But if you're going to modify a stock manifold... that's the way to do it.

Here's a pic. You can see how it was cut apart. Good enough for 400RWHP at 17psi/415RWHP at 18psi (in conjunction with the other top end mods...)




TonyG

Duke

How come every post in this thread is about flow, intake manifold is not just about flow.
Runner length optimizes VE for different rpm-ranges.

For an engine optizmed for higher rpm-ranges, a short runner intake makes sense.
But if you haven't changed headers, worked the head, changed the cam, changed turbo plus all the supporting mods - another intake manifold probably won't gain you anything.

ausgeflippt951

I'm not sure I understand your qualm. Um, flow is more than just pressures and velocities. Think mass flow rate and you'll see that runner lengths and plenum volumes are also all about flow. Even inherent harmonic frequencies are all about flow. It's always all about flow.

blown 944

Duke,
I tried to encompass the runner length issue w/i the inducer statement .

Typically I wouldn't expect anyone to care about low end TQ (below 4k) if they are running larger than a 60 mm inducer

Duke

it is obvious that everyone that is talking about FLOW in this thread is talking about xxx CFM total flow on a bench. And not flow at different RPM levels with valves opening/closing where harmonic freq. come into play!
That's why I state that you also have to include runner length when talking about intake manifolds.
As with most engine related tuning, it's often comes down to FLOW. But in order to discuss the parameters behind different flow characteristics you have to discuss different parameters in the engine design.
We cannot have an intake manifold discussion and just say "it flows more" and be happy with it just because flow is the end result.

evil 944t

Duke, I understand but you are getting to detailed. I'm only going by what the original poster asked. IMHO, long or short runners is not going to help out unless you have other supporting mods.. Anything other than stock is only going to hurt a stock configuration. I also speak from not only flowbench experience but I real world tested a vendors intake and it killed performance. I will not get into details but there were more than just runner sizes that killed it.

seattle951

I have a LR manifold that I am going to replace with a stock unit. I want the longer runners and harmonics from the stock unit for low end TQ and to more quickly spool the turbo. I plan to stay at 17 psi boost with 320 to 360 RWHP. There is no upside for me for the LR manifold, only downside.

I was planning on selling the LR manifold. Since I need a stock unit, I would consider a swap as part of the deal. If you are interested, please PM me.