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There are frequent questions about various intake manifolds and a lot of misinformation floating around. I've compiled some hard data from various sources and gathered it here.
First, one of our sponsors, Richard at WCCH flow tested several manifolds. Here are the flow numbers:
Second, the Jan/Feb issue of Street Thunder Magazine ran a comparo of various intakes and TB combinations on a 236/241 .602/.567 113lsa cammed, ARP'd LS1 with stock 243 heads. All tests except the spyder used the same tune (all tunes created by the same tuner however). Flow matched 28 lb/hr injectors where used for all tests. All manifolds were "out of the box". The full article can be found here: http://www.tpis.com/plog/index.php?o...Id=14&blogId=1
**I neglected to mention that the TPIS Spyder looks identical to the Vic Jr.**
Here are the charts:
I'm still looking for more data, so if you've got some, please post it up.
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Hello, my name is Erik and I am a horsepower addict...
I have the dyno data from the Chevy High Performance intake test in an Excel spreadsheet. I have it set up to compare the Truck, LS6, and FAST 90 intakes with different cams. I just have no idea how to get that spreadsheet into a post. Plus it's pretty big.
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2003 Silverado RCSB - heads, cam, everything but the kitchen sink - SOLD 4/28/09
Thanks for posting those numbers up Erik... I was getting tired of linking people to them and posting them up all over the 'net LOL... bout time it was consolidated into one post/thread
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2001 GMC RCSS 4.3>GEN IV swap
2000 Chevy ECSB Lifted 2WD, 4.8, Rossler built 80E, 3.73's on 33's
I've been doing some research for a little project of mine and found some info about G.M's intake manifolds that might be usefull...
A little more info; The bigger the Plenum, the better it will perfom at top-end, the smaller the Plenum the better it will perform at low to mid range.
The longer the runners the better it will perfom at low-end, and the shorter the runners the better it will perform at WOT. The bigger the intake runner the better WOT performance, the smaller the runner the better low-end performance.
This is a great thread, should help a lot of people out
I'm going to quote some info that I saw Richard post in another thread that I think would be helpful to some of the guys looking at swapping manifolds:
Quote:
Originally Posted by Richard@WCCH
This topic has many tenticles but I'll try to highlight some of the major items.
First, I consider the intake manifold to be a "tuning tool" to compliment the rest of the engine combo. There's more than just static flow to consider when making a manifold selection. The runner cross sectional size and more importantly the length have an impact on the torque range of the engine. Throttle body size come into play at higher rpm levels. Small engines generally don't have much low end torque to give up especially in a truck, and a high rpm manifold like the Victor would reduce the low end torque and add some real, real high rpm power. More than likely too high up the rpm range to see a gain in your useable power band and the loss of low end you would experinece would make that manifold choice undesirable.
IMO the manifold/engine combos should follow along these lines.
4.8l/5.3l and 6.0l engines with a stock or near stock cam and heads should retain the stock truck intakes. They don't demand enough airflow to warrant shorter runner lengths and higher airflow rates.
Once the engine and other related driveline mods are added, the manifold options become a little more diverse. Larger displacement (370-427ci) engines can more easily utilize a LS6, FAST 90 or Victor w/elbow with shorter duration cams than a 4.8l/5.3l. The smaller ci engines will need a cam somewhere in the mid 220º or larger to fully utilize the higher rpm intakes. Always bear in mind we're tuning heavier trucks and not lighter weight cars here and that makes a difference especially with vehicle useage.
I see Erik has mad a sticky related to intake manifolds. A graphic would help guys figure out what manifold possibilities they should consider to help optimize their combo. More of a "general guidline" of intake selection. I think engine displacements should relate to the corresponding rpm ranges. Rpm ranges are influenced mainly by cam selection. Cylinder head work will have an impact in the mid range and upper rpm area. Other items such as gear and converter are also important to intake selection and should be noted. Since manifolds are a nice tuning tool this would help narrow down the selection process for given engine displacement and rpm range.
Intake manifolds are an extremely important decision to the modding process and I'm pleased to see some heightened interest in this subject. I only wish some intake manufacturers would step up and offer an improved manifold that would bolt onto our trucks.
Well for what it is worth, Most of the info I have found believe for best WOT performance the Plenum volume needs to be the same size as engine displacment, but you can see from the crappy table I made that the later LS6 intake manifolds got closer to that line of thinking with the 5.19 plenum volume.
Intake manifold hard data
hers!)
and found some info about G.M's intake manifolds that might be usefull...
