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^ i have. not sure if it has to do with the difficulty in tuning a 102
combo, or how 20mm makes such a huge difference.. and reading
it on the interwebz doesn't make it true either, but i have seen comments
along those lines.
No one reputable will tell you a 102 makes less power than a 92... Because they don't. You can't compare 2 different cars on 2 different days it just doesn't work that way. You would have to have one intake then swap it to the other and dyno it. Vengeance did that when the 102 came out and it gained 9hp over the 92 that was on the car. Same dyno, same car, same day.
If you ever open up the 2 intakes you'll see as well. The 102 has 8 individual runners like the msd does whereas the 92 is a 3 pieces fixed dan which design. The 102 also has a lot more plenum volume in addition to the better runners. Routinely, ported to ported or stock to stock a 102 will make 5-10 hp more than the 92. Tuning a 102 is no different than tuning a 92 at wot so that doesn't effect power. The harder tuning is due to a 102 TB which even then isn't a big problem
That dyno looks about right for a bolt on car. However neither intake will do much for a stock ls1 until you add a cam
^ i have. not sure if it has to do with the difficulty in tuning a 102 combo, or how 20mm makes such a huge difference.. and reading it on the interwebz doesn't make it true either, but i have seen comments along those lines.
I'm struggling with this one. Are y'all saying the 92 always beats the 102 or are we talking basically stock engines? I can sort of twist my brain into thinking a 92 might be better on otherwise stock due to air demand, but I would think a max effort engine would absolutely do better with the extra air.
Modern intakes aren't like carbs, you can't over intake a car. The engine will only take as much air as it needs to operate the runners are what determines power an where it's going to occur at hence why longer runners typically make more torque and shorter ones more hp. That larger plenum volume of the 102 allows it to have more air on demand for the engines need nothing more
I think it would depend on CI and the heads/cam set up. It's not all about fitting more air, you need to keep the air velocity up. If the intake flows more air, but slowly, you won't get much good from it.
Modern intakes aren't like carbs, you can't over intake a car. The engine will only take as much air as it needs to operate the runners are what determines power an where it's going to occur at hence why longer runners typically make more torque and shorter ones more hp. That larger plenum volume of the 102 allows it to have more air on demand for the engines need nothing more
NOT true at all. If you over intake an engine it will KILL air velocity as Mongoose just explained, and in the process you will kill power in the car.
Watch the vacuum(map sensor) on an intake manifold drop to zero on an intake with an enormous throttle body MAYBE 75% of the way open and youll understand what i mean.
"=redbird555;18895004]Modern intakes aren't like carbs, you can't over intake a car. The engine will only take as much air as it needs to operate the runners are what determines power an where it's going to occur at hence why longer runners typically make more torque and shorter ones more hp. That larger plenum volume of the 102 allows it to have more air on demand for the engines need nothing more
NOT true at all. If you over intake an engine it will KILL air velocity as Mongoose just explained, and in the process you will kill power in the car.
Watch the vacuum(map sensor) on an intake manifold drop to zero on an intake with an enormous throttle body MAYBE 75% of the way open and youll understand what i mean.
I will stand by my statement in saying that a modern intake is not like a carb in the least. Are the principles the same? Yes. but that's it. A carb becomes too big because it injects too much fuel and the bores of the carb begin to slow down velocity. Now this will vary with what type of carb you have but the principle is the same. In a modern car just as I stated the size of the intake doesn't matter. A 102mm opening on the tb side isn't going to make velocity at the runners any different.
Notice where I said its runners that determine what happens. I stated the 102 wasn't too big for an ls1 and also that no intake is too big for an ls1... Which is 100% true as long as the runners are kept in check. The runners are what control the velocity going into the port not the plenum.
The intake can be a 55 gallon drop for all anyone cares, as long as the runners are optimized for the combo the motor doesn't care what the plenum volume is. Too small of a plenum volume causes vacuum at wot which becomes a restriction. People constantly say the 102 is too big for a 346 because its 102 mm, little do they know that opening has 0 to do with the power band. Believe me im plenty aware what happens at 101kpa in the intake. However that again is mostly determined by the runner shape rather than how big the intake "box" is
Also do you have any idea just how big you would have to make runners that reach 101kpa at 75% throttle? It would be massive and I doubt any company marketing an intake for ls motors wold let that happen. So please don't take it to a .001% chance scenario
Last edited by redbird555; 07-23-2015 at 08:08 AM.
Plus with MPFI the air velocity in the runner is much less important for fuel atomization like in the old carb days.
Thanks hammer i was just about to add that but ya beat me to it. You're not mixing air and fuel in the throat then having to "carry" that heavier mixture to the ports. Instead you're carrying lighter pure air to the runners and injecting fuel right at the port, pretty apples to oranges deal.
Too many people here applying what was learned in 1965 rather than how its applied in 2015.
I'm struggling with this one. Are y'all saying the 92 always beats the 102 or are we talking basically stock engines? I can sort of twist my brain into thinking a 92 might be better on otherwise stock due to air demand, but I would think a max effort engine would absolutely do better with the extra air.
I wouldn't worry if I were you. If Tony steered you toward the FAST 102 for the setup that he spec'd for you, then I wouldn't second guess that.
Has anyone else looked at the bottom of these intakes. The injectors don't sit flush. It looks like it could be recessed enough to affect the spray pattern.
05-09-2016, 12:20 PM
