ls1 intake vs truck intake. thoughts
03-02-2006, 06:15 PM
#23
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Originally Posted by goshawk23
thanks for posting. a little work is involved but it is doable and for under 200 bucks from what i can see. granted you have to leave a little money on the table for the incidentals. how was the top end once you got it on. or was the tuning problem keeping you from fully enjoying it.
03-02-2006, 11:11 PM
#24
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Originally Posted by Richard@WCCH
My observation of the truck intakes is that major high flow restrictions exist in the transition from the flow tube located behind the throttle body and the upper plenum which feeds the runners. In the case of the front 4 cylinders, high flowing air heading to the back of the manifold must negotiate a 180º turn and head towards the front of the engine. This increases the part throttle torque and makes the pedal response crisp do to the long flow passage. However at higher flow rates, the air simply cannot maneuver through all the turns quickly enough to fill the cylinders as needed. Think dual plane intakes on the Gen 1 Chevy. Good low end torque and pedal response but lacking high rpm airflow capability. Also think about the car intakes as a single plane style intake. Less low end torque and better high rpm power. I won't go into the sound frequencies discussion here..........
Richard
Richard
Well put Richard
about the 180
that seems like it would be a huge task for getting the airflow to the front runners
and, its got to accomplish this before the valve slams completely shut
by then a back one opens and the cycle repeats itself
Trying to put it in perspective here
Doesnt this happen 50 times per second at 6000rpm?
(IVO and or IVC)Doesnt those front pistons have to work harder to overcome this 180
turn?
If this theory is correct
I cant see the truck intake being anything but a setback
for us guys that want to make power over 5000
another thing on air fuel distribution
and in addition to what Richard said...
We tune our engines based on the readings we see from
one or two points ....wideband or narrowband
if 4 of our cylinders are rich and the other half are lean
Then we're just getting avg'd readings
how much power is left
or better yet...how safe is that
It would be interesting to see someone put widebands on each primary
and compare results between the 8
03-02-2006, 11:34 PM
#25
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Originally Posted by Kano
Well put Richard
about the 180
that seems like it would be a huge task for getting the airflow to the front runners
and, its got to accomplish this before the valve slams completely shut
by then a back one opens and the cycle repeats itself
Trying to put it in perspective here
Doesnt this happen 50 times per second at 6000rpm? (IVO and or IVC)
Doesnt those front pistons have to work harder to overcome this 180
turn?
If this theory is correct
I cant see the truck intake being anything but a setback
for us guys that want to make power over 5000
another thing on air fuel distribution
and in addition to what Richard said...
We tune our engines based on the readings we see from
one or two points ....wideband or narrowband
if 4 of our cylinders are rich and the other half are lean
Then we're just getting avg'd readings
how much power is left
or better yet...how safe is that
It would be interesting to see someone put widebands on each primary
and compare results between the 8
about the 180
that seems like it would be a huge task for getting the airflow to the front runners
and, its got to accomplish this before the valve slams completely shut
by then a back one opens and the cycle repeats itself
Trying to put it in perspective here
Doesnt this happen 50 times per second at 6000rpm?
(IVO and or IVC)Doesnt those front pistons have to work harder to overcome this 180
turn?
If this theory is correct
I cant see the truck intake being anything but a setback
for us guys that want to make power over 5000
another thing on air fuel distribution
and in addition to what Richard said...
We tune our engines based on the readings we see from
one or two points ....wideband or narrowband
if 4 of our cylinders are rich and the other half are lean
Then we're just getting avg'd readings
how much power is left
or better yet...how safe is that
It would be interesting to see someone put widebands on each primary
and compare results between the 8
03-03-2006, 08:02 AM
#26
FormerVendor
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Originally Posted by Wong
Does anyone know anyone thats done a straight engine dyno. The one by me will mesure EGT's of each exhaust port. It would be interesting to find out.
I know the folks at Magnusson have done extensive testing on 5.3l engines. I'm sure most of it is with a blower and not the stock intake.
Kano your touching on something I've been curious about for a while. Cylinders that don't fill the same amount of air will run rich or lean depending on the amount of air they recieve. The O2 sensors are reporting an average of the bank of 4 cylinders. Some cylinders are propably running richer than the target AFR and some are running leaner.
I know of a recent test done where an Edelbrock Victor Jr. intake and sheet metal elbow were tested back to back against a FAST 90 intake. The Edelbrock w/elbow setup lost 50 rwhp. I can't say how much of the loss was due to the elbow setup. I'm sure a 4bbl throttle body would have done better as I have seen dyno results of engines with single plane carb intakes make great power. Soon I'll be working with a guy who will spend some quality time on an engine dyno testing a variety of intake setups. I'll post up when more data is available.
Richard
03-03-2006, 08:43 AM
#27
The TPIS spyder (identical to the Vic Jr.) came out on top of the FAST 90 in CHP's test. Here's a link to the article. They don't explicitly say so, but it looks like no elbow.
Interstingly enough, if you look at a useable max RPM for most trucks, say 6400 rpm, the LS2 car intake makes the best numbers.
Interstingly enough, if you look at a useable max RPM for most trucks, say 6400 rpm, the LS2 car intake makes the best numbers.
03-03-2006, 12:39 PM
#28
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thats some good info on the intake manifolds. it will take me a while but i'm gonna read through it and try and understand a little more on the subject.
03-06-2006, 12:09 AM
#29
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Originally Posted by Richard@WCCH
I know of a recent test done where an Edelbrock Victor Jr. intake and sheet metal elbow were tested back to back against a FAST 90 intake. The Edelbrock w/elbow setup lost 50 rwhp. I can't say how much of the loss was due to the elbow setup. I'm sure a 4bbl throttle body would have done better as I have seen dyno results of engines with single plane carb intakes make great power. Soon I'll be working with a guy who will spend some quality time on an engine dyno testing a variety of intake setups. I'll post up when more data is available.
Richard
damn
Im glad I wasnt betting on that one cause I would have lost my ***
I agree thats quite a bit of volume between the TB and the manifold
with the elbow and all
never would have thought it would make that much difference though
Ive always held the old style single plains as being optimum as far as peak HP
is concerned
too bad someone doesnt make a 4 bbl TB thats plug n play
thanks for being so involved
as always
I look forward to seeing your results
