Don't Need to Spend a Lot of Money to Get a Much Better Exhaust and Intake for Your S-10 V6

The two techniques below were used to gain significant flow improvements for minor cost:

Click to See Exhaust Improvements:

Click to See 1994 Intake Improvements:

Click to See 2002 Intake Improvements:

MIG Gas Delivery and the Small Block Chevy Evolved in a Similar Way and Time!

 Both had Advances and Setbacks Before

They Were Optimized!

Click for a PDF Report on the Similarities

On both a 1994 and 2002 S-10 had a local muffler shop install a Flowmaster muffler with two 2/1/2 inch outlets from the one muffler making dual exhausts.  This fellow is an absolute genius at bending tubing to clear the spare tire etc even on the Stepside.  Since I didn't change anything upstream of the muffler did I gain a lot of HP?  Probably not but the sound was great!  However on the '94 when changing oil I would  look at GM's "squashed" exhaust crossover pipe coming from the Driver to Passenger side as it passed under the standard transmission. It was obviously the biggest restriction in the system (See Photo Above!)  Particularly with hot exhaust gases that occupy more space than when they cool off.  The only reason I could think for GM doing that was the small Ford pick-up must have had another inch of ground clearance and they wanted to match the specs!!

When the Flowmaster was being installed on the 2002 I asked to have the flattened crossover section cut out and replaced.  Turns out the pipe is only 1.46 inch ID to start with and when flattened the area reduces to the equivalent of a pipe only 1.2 inches in inside diameter! You must be kidding - I was installing 2 1/2 inch duals back stream when all the exhaust exiting the Drivers side was going through a pipe with only 23% of the area of one 2 1/2 inch exhaust pipe and hot gas at that!  The installer removed the whole crossover and bent a piece of 1 3/4 inch pipe to the same shape, slipped it on the cut stubs and welded it in.  This way he stayed away from the transmission.  Not quite fully 1 3/4 inch ID the whole way but close.  Doesn't sound like much but compared to the flattened 1.46 inch pipe it's more that twice the area!  Did install high temp insulation between the pipe and the transmission with two stainless band clamps just in case.  The end result was a pipe about 1/2 inch closer to the ground so   little ground clearance was lost.

'94 S-10 V6 INTAKE

The 1994 intake used a Helmholtz device to reduce intake noise.  It looks like a Bull Sea Lion Trumpet and the device probably performs in the same way!  It is designed to provide a sound wave at particular flows to cancel specific intake air flow waves. 

Don't think Intake Air doesn't make a lot of noise-it does!  On the 502/502 Big Block in my 1934 Street rod, even though it has long tube headers with straight through Bola Mufflers and 3 inch exhaust (SEE LINK) the intake with the 5 inch X 14 inch K&N makes as much noise than the exhaust at full throttle!

To make the system work GM necked down the air intake passage and in the smallest part it measured 2.27 square inches.  To provide more area I just cut out the bottom of that section and bent some aluminum sheet in a "U" shape.  A few sheet metal screws attached it to the plastic air cleaner cover and some black paint and black silicon sealed it perfectly.  The intake does takes air from the front of the radiator baffle so its cool. Used a K&N air cleaner to replace the stock paper filter and now the narrowest area was 4.47 square inches.  Much better than some of the expensive kits I've seen which put a conical K&N in the hot engine compartment!

2002 S-10 V6 INTAKE

The 2002 S-10 had a much better arrangement.  The intake opening still received air from ahead of the radiator baffle-a good thing!  Perhaps to help provide the extra power they eliminated the Bull Sea Lion Trumpet!  The smallest area in the intake was now a reduced section (probably there again to help with noise) which at its narrowest was 3.14 square inches.  Much better than the '94 but not as large as I was finally able to increase it.  However a quick review of the other restrictions indicated it wasn't that much smaller.  So decided to just "port the passage!"  Now "porting" plastic is no big deal so "just do it."  Used a file and coarse sand paper to clean up first the plastic seem lines which were pretty heavy.  Then worked the narrow area to smooth it out and thin the wall.  The plastic is quite heavy, probably for the case area but no need in the intake passage.  Was able to increase the area to 3.46 square inches by my calculations and decided that was good enough considering the other restrictions in the system.  Added a K&N filter to replace the original paper filter.  A very inexpensive modification.

Engineering a 1934 Pro Street Rod

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