SV1 Dyno / Track

Here are some real world dyno numbers showing the best four barrel carburetors that we knew of (some of their prices exceeding $1800.00 each) and they were ultimately fine tuned by us at Pro Systems and the folks at SMRE to extract their maximum horsepower and ensure a level playing field for the air density requirements.  Yes, some of the carbs in this test are ours, but we all have or have heard of those magical carbs that we have stumbled across that for some reason make more power than they should and have not been able to duplicate…those are in this test too.

As a side note:  It is very important that we truly tried to get everything out of the four barrel design that we possibly could in order to ensure that we could beat a four barrel carburetors output BEFORE we released the SV1 to market.  If the SV1 truly was not a better piece, it was not going to be released.  Below is the road we traveled to verify that we accomplished that task.

The main four barrel carburetor competitor for this shootout was a 1100 cfm based carburetor design (other competitors in this cfm range were down 15-20 h.p. from this carb) and as you can see it was able to be tuned to achieve a peak horsepower number of 771 horsepower and 632 lbs of torque. (see the 1100 carb link below).  BUT the 1100 was down 10 horsepower and 8 lbs of torque from the SV1.

You’ll also notice how up and down the power output chart is with the four barrel carburetors.   As a note: We kept the “smoothing rate” of the data entering the dyno very low to expose weaknesses like this.

As odd as that spikeyness seemed, it is typical at this smoothness setting in all the four barrel designs we tested, BUT NOT in the SV1.  Although this spikeyness was an advantage to the four barrel carbs in peak numbers for this test it was important you saw these spikes as compared to the SV1’s smoothness in the same situation.

The SV1 is smooth and made 781 horsepower and hung on for several hundred rpms, the engine sounds smooth too with the SV1 feeding it.  The SV1 showed the 1100 that you can make the power and that the SV1 could make power smoothly and for a broader range.  Attempts to smooth the 1100 four barrel carburetors power outputs and get rid of the spikes, barely helped and showed pretty big losses in power output and put it back inline with the other carburetors that now resided on the “loser shelf”.

Finally just for fun we installed a few big carbs on the little 509 c.i. engine to check the effect.  Many times the bigger carburetors will show us big dyno results, but as we all know those big carbs are terribly slow in acceleration on the race track.  But I wanted the four barrel carb to have an unfair advantage over the smaller SV1 and see what it could do with it.  The first few big four barrel carbs from other suppliers were not so good and were down 20-30 lbs of torque below 5000 rpms so we knew they did not stand a chance and they went back to the loser shelf.

We did however, find a 1240 cfm four barrel carb that looked promising but was down on power, so we took the design back to the shop and worked on it for awhile.   We brought it back to the session with a new layout looking to put the smaller 1125 cfm SV1 on the trailer.

The 1240 cfm four barrel carb was still down 10 lbs of torque for much of the pull (notice on the dyno graph the lower torque output for much of the run) but the 1240 finally eeked a single lb of torque advantage at one point in the pull and fell only 2 horsepower short of the SV1’s 781 h.p. peak.  But the average on the four barrel 1240 was so low on the pull, it was not a contender in the real world.

Also, once again like the other four barrel carburetors it was spikey at that dyno “smoothing rate” in power output and everytime we tried to smooth it to get rid of the spikes, the power would also fall off and the spikes were only reduced slightly.  Attempts to get the 1240 cfm carb as smooth as the SV1 were not really possible but we got it better, but by then the 1240 cfm could then only match the 771 h.p. output of the original 1100 cfm carb.  So this makes the peaks and spikes suspect numbers that are possibly misleading (subject we’ll get to in a moment).

As I said earlier, we purposely set the smoothing rate on the dyno very low so as to expose issues like these up and down spikes.  The real world will see these spikey power outputs in poor consistency, acceleration performance and overall difficult tuneability.

All in all the SV1 typically shows a real world gain at peak of about 10 h.p.  BUT, in at the track testing results, due to its hard launching and fast shift recovery capability and smooth power output, the SV1 shows a power number that is more inline with an estimated 15 horsepower range over the best carburetors we could get our hands on and these carbs were professionally tuned to battle the SV1 to ensure a fair fight.

A real world test of the fastest four barrel carb versus the SV1 in a 3300 lb. door car.  The SV1 is on the right. At that weight it takes about 12-15 h.p. to achieve those elapsed time improvements.  This is the fastest E.T. the four barrel carb achieved (the car was very shallow staged/light blinking).

Time after time, reports from customers and engine builders state the average horsepower and torque numbers are typically 10 higher than a finely tuned four barrel carb AND the SV1 proves its superior atomization capabilities in the real world as it makes it best power typically .5 of a air to fuel ratio leaner than all of our tested four barrel carburetors.

So if you are looking for a clear winner, these results are from a professionally done shoot out that was designed to compare the best against the best and tuned by folks who have tuned some of the best racecars in the business.  All in an effort to get real results.

The results: The SV1 is the winning carburetor.  So…..they are now available.

To quote David Reher of Reher Morrison:  The SV1 is the most innovative thing I have ever seen in carburetor design.  If this carburetor does everything it looks like it should do…no one will run a four barrel carburetor anymore.

Check out the dyno results below….and just for fun…I included a “pie in the sky” dyno test of the SV1 submitted to us by BES.  This B.E.S. dyno sheet is from a real world circle track application.  In circle track racing they incorporate smaller carbs for much needed fast throttle response on the track.  A larger four barrel carb typically shows B.E.S. 10-15 more h.p. compared to the smaller four barrel (so the big four barrel would then only lose to the SV1 by 10-15 h.p. instead of 24 h.p. as shown).  But in the real world the big four barrel lacks the throttle response that the smaller four barrel and the SV1 does offer.  So in this real world application the SV1 can be employed and ultimately came out the winner by 24 horsepower!  Not a circle track racer?  Use this info and think SV1 if you are a foot brake bracket racer.  With the SV1, you can get maximum power and not give up throttle response!