Boost intake. What's everyone running?

**Injuneer** · 01-19-2017, 11:37 AM

18 years ago, George Baxter ran the LT1 intake at 20+ # boost (Canfield heads, 1,125 flywheel HP), no distribution problems. Second Street copied George's setup for someone else, no problems. They said exactly what firebird_1995 said.... the distribution problems with the LT1 intake are encountered running a nitrous plate. Even with a dry system, they told me not to run a plate. Putting the nozzles 10" in front of the throttle body, no distribution problems. I watched them pull the plugs on repeated pulls on the engine dyno and on the chassis dyno tuning.

**Catmaigne** · 01-19-2017, 11:17 PM

Originally Posted by GuillaumeC

I had a stock unported LT1 manifold on the Caprice, running 18-20 psi max. I had distribution issues, the plugs weren't the same color front & back and seemed to get worse as the boost went up.

Were you running a stock throttle body or something larger?

**GuillaumeC** · 01-20-2017, 08:10 AM

52mm TB, 100% stock untouched manifold.

It could have been something else I guess, I just dont see what.

**Injuneer** · 01-20-2017, 01:48 PM

The smaller the throttle body, the higher the velocity through it. Directionally, the stream will penetrate further into the plenum before it disburses, and allow the plenum to function as a distribution device. Just a thought.

I run a 58mm through a seriously ported (by CNC Cylinder Heads) LT4 intake. Baxter ran a 58mm through a ported (by Lingenfelter) LT1 intake.

**GuillaumeC** · 01-20-2017, 01:57 PM

True, I didn't think about that.

The new combo has a Victor E, 6061.com elbow and LS style throttle body. I think it'll work fine.

***SSlowBoat*** · 01-20-2017, 06:51 PM

Originally Posted by Injuneer

The smaller the throttle body, the higher the velocity through it. Directionally, the stream will penetrate further into the plenum before it disburses, and allow the plenum to function as a distribution device. Just a thought.

I run a 58mm through a seriously ported (by CNC Cylinder Heads) LT4 intake. Baxter ran a 58mm through a ported (by Lingenfelter) LT1 intake.

58mm tpis twin blade and le ported stocker.

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**Jeff Green** · 11-05-2017, 12:22 PM

FWIW and not to argue with anyone's points on here. I'll give a slightly different perspective based on the equipment I use.

Almost all intakes have a stagger and it get's larger when you add boost. Why maybe I know this is only because I run an 8 channel wideband on my engine at all times. So I see each cylinder and what it's doing and not a sum of the total like a bank O2. My guess is you are not going to be able to read a plug to the degree you can read an AFR on a wide band chart. I would like to meet the guy that can read a plug that fine as I have never seen anyone that could. I can pull two plugs out of my engine and let someone try to read them by looking at them. They all have said they pretty much look the same and then I show them the wideband graph per cylinder and how much they are different. While air turns much better than liquid there's still resistance to air turning. Even firing order comes into play on which cylinders will show lean on FI setups. Even the fact our intakes are front loads causes issues over a top load. The nitrous issue is true and that's wet or dry, wet is worse because fuel is heavy and can't make the sharp turn. Even the nitrous gas has issues making sharp turns.

I have always had to run staggers on my fuel from cylinder to cylinder to get balance. And a balanced engine, AFR per cylinder, will make more power than if the sum of the total bank looks good on an O2. Lots of factors go into how much air each cylinder gets/takes, more so than just the intake. EGT's have their place and I have both EGT's and the wideband on the car. The problem with EGT's is you really have to burn the motor up to know what the readings really mean, other than it's just way wrong!! That's where the wideband comes in as the AFR is the AFR. But issue like detonation will not show up on the wideband but your EGT's will take off.

To add an eight channel wideband in your car makes no dollar sense just for you to be able to balance your engine. A good one is thousands of dollars and only pays for themselves when you can avoid burning up an engine using the data they provide.

Most people, actually I have never seen anyone other then me, don't have an eight channel wideband setup in their car. I couldn't do what I do without it as with all data logging systems you get info you would never know was going on otherwise.

Hope its useful info