TB upgrade....is it worth it?
Thread Starter
Racer
Joined: Jun 2012
Posts: 283
Likes: 9
From: Thibodaux Louisiana
TB upgrade....is it worth it?
I just bought a ls6 intake, fuel rails, throttle body for my 98 c5 auto. I also just bought a vararam intake, 25% underdrive kit, and a set of long tubes. Going to do a mail order ecm upgrade and delete cats. My question is....the guy i bought the ls6 set up from also has a ported/polished aftermarket 85mm TB for $150, is it worth it, or just port/polish my stock?
Pro
Joined: Nov 2010
Posts: 514
Likes: 21
I just bought a ls6 intake, fuel rails, throttle body for my 98 c5 auto. I also just bought a vararam intake, 25% underdrive kit, and a set of long tubes. Going to do a mail order ecm upgrade and delete cats. My question is....the guy i bought the ls6 set up from also has a ported/polished aftermarket 85mm TB for $150, is it worth it, or just port/polish my stock?
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
not worth it, you can send yours to bare essential racing and get it P/P for cheaper than that and it will match right up to the LS6 intake. what good is a 85mm TB if the intake opening is still 78mm? ECS does great mail in tunes. There really is no need to spend 400 bucks on a dyno tune with those basic of mods. Yes, they set it conservatively but my 00 with just long tubes and a ECS mail in put down 330 on its baseline.
Premium Supporting Vendor
Joined: Oct 2004
Posts: 23,599
Likes: 1,224
From: Providing the most proven supercharger kits for your C5/6/7 609-752-0321
Ported TB's add next to no additional power and generally cause more idle issue's then anything. Save your money for a "real" mod IMO.
Twin cone air filters, after market MAF's fall in the same category.
Twin cone air filters, after market MAF's fall in the same category.
Tech Contributor
Joined: Jan 2004
Posts: 20,030
Likes: 289
From: Wylie TX --> Less is More, except under the hood !
not worth it, you can send yours to bare essential racing and get it P/P for cheaper than that and it will match right up to the LS6 intake. what good is a 85mm TB if the intake opening is still 78mm? ECS does great mail in tunes. There really is no need to spend 400 bucks on a dyno tune with those basic of mods. Yes, they set it conservatively but my 00 with just long tubes and a ECS mail in put down 330 on its baseline.
Its not a bad thing if you have a smaller TB going into a larger intake (ie 90mm LS2 into a 92mm FAST). I would think it would be bad having a larger TB going into a smaller intake. I would think it would cause some air turbulance issues.
I would port/polish your stock TB. I got Shanner to port and polish my old LS6 TB and I put it on with no other changes on my car. I immediately noticed a marked improvement in throttle response. I don't know if I really added any HP because a month later I had a full heads/cam setup installed. I wanted the TB done before I got the whole heads/cam setup tuned.
Hope this helps.
Toque
My unported 90mm LS2 TB.
My ported 90mm LS2, and 78mm LS6 TB.
The inside of the stock LS6/LS1 TB are horrible ! Its like 10 grade sandpaper.
I wish I had a pic of it before I polished it.
Last edited by Toque; Aug 8, 2012 at 09:10 AM.
