vararam power duct worth it?
Thread Starter
Instructor
Joined: Jun 2009
Posts: 128
Likes: 0
From: Sioux Falls South Dakota
vararam power duct worth it?
98 auto
my mods are, Vararam B2, cam, headers, no cats, corsa, tune, ect...
since i already have the B2 setup, i was wondering if the power duct is worth the $100?
comments? suggestions?
my mods are, Vararam B2, cam, headers, no cats, corsa, tune, ect...
since i already have the B2 setup, i was wondering if the power duct is worth the $100?
comments? suggestions?
Thread Starter
Instructor
Joined: Jun 2009
Posts: 128
Likes: 0
From: Sioux Falls South Dakota
Instructor
Joined: Aug 2009
Posts: 103
Likes: 4
From: Galt CA
I have the vararam with the power duct. I asked my tuner and he told me that it will help. Not sure what the gains were with the power duct because I had the car tuned with both of them in place already. I got it at Maryland speed for around 80.00 As far as the throttle body goes I looked on the forum for a long time and ended up going with a Shaner S2 ported throttle body. He does a beautiful job. If you look up Shaner S2 throttle body's on the forum you can see what people have written about them. It is definitely one of the first mods you should do. He is a nice guy he will talk your ear off.
Race Director
Joined: Mar 2008
Posts: 12,413
Likes: 502
From: Rio Rancho NM
When I installed mine I got lean codes so I assumed more air was coming in but never really felt anything. Even when I had a ported TB I never felt anything. I would save your money and get a tune that's what I did and that I could feel.
Instructor
Joined: Aug 2009
Posts: 103
Likes: 4
From: Galt CA
Yea like I said I installed the power duct when I had it tuned so I am not sure. I could definitely feel a difference when I installed the vararam though. I installed that a few months before. As far as the T.B. goes I do think I felt a difference but it might have been better throttle response more than HP but I could feel it.
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Tech Contributor
Joined: Dec 1999
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I don't think any of the single small bolt on parts is going to make a very large gain. Getting a NOTICEABLE HP/TQ gain results from adding building blocks of parts tuned together to make power.
When ever you alter the factory tune by bolting on something or changing something that allows more air to flow thru the engine, the PCM will do what its designed to do to and add or remove CLOSED LOOP fuel by adding or subtracting thru Long Term Fuel Trims (LTFT) to maintain 14.7:1 part throttle AFR. It can ONLY adjust +- 25% The further away that the LTFT's get from zero, the less efficient your engine becomes in closed loop. Closed Loop fuel trims being way out of spec also effect your open loop Power Enrichment (PE) tables
The reason you Butt O Meter feels HP increases when you hammer it, is that the PCM goes into OPEN LOOP and that added air flow makes a change in the Power Enrichment (PE) tables AFR. Hopefully it helps your PE AFR get closer to 12.7:1 thus more power. Sadly, sometimes it doesn't improve PE AFR and you can even see a power loss until tuning is done to correct the LTFT, PE AFR's and adjust timing and MAF tables.
My ported TB made significant improvement in throttle response. Cant tell you how HP my ported TB alone gave me but my throttle response was a lot better.
Add headers, efficient mid pipe, cold air intake, better intake (LS6 if you don't already have one) and a ported TB and then have it tuned and that will make a nice difference.
When ever you alter the factory tune by bolting on something or changing something that allows more air to flow thru the engine, the PCM will do what its designed to do to and add or remove CLOSED LOOP fuel by adding or subtracting thru Long Term Fuel Trims (LTFT) to maintain 14.7:1 part throttle AFR. It can ONLY adjust +- 25% The further away that the LTFT's get from zero, the less efficient your engine becomes in closed loop. Closed Loop fuel trims being way out of spec also effect your open loop Power Enrichment (PE) tables
The reason you Butt O Meter feels HP increases when you hammer it, is that the PCM goes into OPEN LOOP and that added air flow makes a change in the Power Enrichment (PE) tables AFR. Hopefully it helps your PE AFR get closer to 12.7:1 thus more power. Sadly, sometimes it doesn't improve PE AFR and you can even see a power loss until tuning is done to correct the LTFT, PE AFR's and adjust timing and MAF tables.
My ported TB made significant improvement in throttle response. Cant tell you how HP my ported TB alone gave me but my throttle response was a lot better.
Add headers, efficient mid pipe, cold air intake, better intake (LS6 if you don't already have one) and a ported TB and then have it tuned and that will make a nice difference.
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From: It's true money can't buy happiness, but it is more comfortable crying in a Corvette than on a bicyc
St. Jude Donor '13
I added the VR Power Duct and the only thing I noticed was my idle smoothed out. I paid a whole lot less than $100. from a vendor here during a sale. It's built better than the intake they sell.
