Generation III External Engine LS1 | LS6 | Bolt-Ons | Intakes | Exhaust | Ignition | Accessories
Sponsored by:
Sponsored by:

LS6 conversion to 90 MM

Thread Tools
 
Search this Thread
 
Old 08-25-2011, 12:11 PM
  #1  
Launching!
Thread Starter
iTrader: (33)
 
Y2K WS6's Avatar
 
Join Date: Apr 2008
Location: Weston, WV
Posts: 262
Likes: 0
Received 0 Likes on 0 Posts

Default LS6 conversion to 90 MM

I have looked around and read quite a lot. I am going to give this one a shot to see what kind of gains i can get on my Cammed 346. anyway my questions are.

Does anyone have epoxy suggestions?

also, does it have to be the snout off of an LS2 manifold or will the 90mm truck intakes work also.

open to all suggestions on this project. I just don't feel like paying $350 for someone else to do something that I can do.
Old 08-25-2011, 12:21 PM
  #2  
On The Tree
iTrader: (3)
 
98z-28redcamaro's Avatar
 
Join Date: Sep 2009
Location: myrtlebeach sc
Posts: 197
Likes: 0
Received 0 Likes on 0 Posts
Default

Tried this????


http://cgi.ebay.com/ebaymotors/LS2-L...item3369de993b
Old 08-25-2011, 12:24 PM
  #3  
Launching!
Thread Starter
iTrader: (33)
 
Y2K WS6's Avatar
 
Join Date: Apr 2008
Location: Weston, WV
Posts: 262
Likes: 0
Received 0 Likes on 0 Posts

Default

I haven't seen anyone who has actually, and it does not make the hole into the manifold any bigger. so I find it hard to see much benefit.
Old 08-25-2011, 12:47 PM
  #4  
On The Tree
iTrader: (3)
 
98z-28redcamaro's Avatar
 
Join Date: Sep 2009
Location: myrtlebeach sc
Posts: 197
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Y2K WS6
I haven't seen anyone who has actually, and it does not make the hole into the manifold any bigger. so I find it hard to see much benefit.
that is very true....... the opening on an ls6 intake is made for a 78mm.....but a lot of people run the bbk 80mm with an adapter ring...and people are still buying it soo it must have some benefit.....as long at the motor is craving more air then the throttle body along with a bigger intake plenum is the key to giving the motor what it wants...but keep in mind that an ls6 intake flows better than the ls2...and the ls6 is giving up throttle body size
Old 08-25-2011, 03:15 PM
  #5  
TECH Apprentice
iTrader: (1)
 
CoastieWS6's Avatar
 
Join Date: Feb 2008
Location: Lake Charles La / Mobile, AL
Posts: 317
Likes: 0
Received 0 Likes on 0 Posts
Default

Here is the link for the company who makes the LS6 intake with a 90mm mouth

http://www.tpis.com/parts/view/39
Old 08-25-2011, 10:47 PM
  #6  
TECH Senior Member
iTrader: (96)
 
01ssreda4's Avatar
 
Join Date: Aug 2007
Location: Turnin' Wrenches Infractions: 005
Posts: 24,240
Likes: 0
Received 79 Likes on 70 Posts

Default

Originally Posted by 98z-28redcamaro
.....but a lot of people run the bbk 80mm with an adapter ring...and people are still buying it soo it must have some benefit.....
Nope, doesn't work that way. People buy Snuggies (backwards robes) so your argument is null and void. You cannot trust people buying something as a valid reason to trust the product.
Old 09-04-2011, 12:21 PM
  #7  
Launching!
Thread Starter
iTrader: (33)
 
Y2K WS6's Avatar
 
Join Date: Apr 2008
Location: Weston, WV
Posts: 262
Likes: 0
Received 0 Likes on 0 Posts

Default

After taking some measurments and thinking, Yes the LS6 intake has a 78 (ish) mm opening. and i have about a 75 mm throttle body.

but in the middle of that there is a blade, and shaft ( that shaft is 10MM in diameter) so my throttle body has an "actual" size of 65 mm so a larger (bbk ) throttle body means it COULD flow that much air.... Still looking for a solution that doesn't cost insane amounts of money $350 for someone to do an ugly glue job + 200 minimum fora throttle body.
Old 09-04-2011, 12:52 PM
  #8  
TECH Junkie
iTrader: (33)
 
LS1-450's Avatar
 
Join Date: Aug 2005
Posts: 3,783
Likes: 0
Received 9 Likes on 8 Posts

Default

Originally Posted by Y2K WS6
After taking some measurments and thinking, Yes the LS6 intake has a 78 (ish) mm opening. and i have about a 75 mm throttle body.

but in the middle of that there is a blade, and shaft ( that shaft is 10MM in diameter) so my throttle body has an "actual" size of 65 mm so a larger (bbk ) throttle body means it COULD flow that much air.... Still looking for a solution that doesn't cost insane amounts of money $350 for someone to do an ugly glue job + 200 minimum fora throttle body.

I don't recall the period, but, think I remember posting how to get the LS6 to 85mm or a little more without the need for cutting off the inlet & then installing the LS2 inlet. It was maybe 1.5-2yrs ago. A search will probably locate it if you're interested in a compromise without the extra hassle.
Old 09-04-2011, 01:52 PM
  #9  
TECH Senior Member
iTrader: (1)
 
sjsingle1's Avatar
 
Join Date: Feb 2010
Location: Fort Worth TX
Posts: 6,498
Received 215 Likes on 176 Posts

Default

not worth it IMO............get a fast
Old 09-04-2011, 02:57 PM
  #10  
TECH Addict
iTrader: (2)
 
Darkman's Avatar
 
Join Date: Apr 2009
Location: Spring, Texas
Posts: 2,167
Likes: 0
Received 5 Likes on 4 Posts
Default

Originally Posted by LS1-450
I don't recall the period, but, think I remember posting how to get the LS6 to 85mm or a little more without the need for cutting off the inlet & then installing the LS2 inlet. It was maybe 1.5-2yrs ago. A search will probably locate it if you're interested in a compromise without the extra hassle.

Maybe this?
https://ls1tech.com/forums/generatio...s6-intake.html
Old 09-04-2011, 08:12 PM
  #11  
TECH Junkie
iTrader: (33)
 
LS1-450's Avatar
 
Join Date: Aug 2005
Posts: 3,783
Likes: 0
Received 9 Likes on 8 Posts

Default

Originally Posted by Darkman

Yah, that's it. 1999BlueTA has a link to it in the first post. Thanks
Old 09-06-2011, 09:00 AM
  #12  
Launching!
Thread Starter
iTrader: (33)
 
Y2K WS6's Avatar
 
Join Date: Apr 2008
Location: Weston, WV
Posts: 262
Likes: 0
Received 0 Likes on 0 Posts

Default

SWEET link .. and very nice job LS1-450 what throttle body did you use. I'm thinking maybe possibly a TBSS throttle body will work with an adapter/spacer on it? i am drive by wire

what precautions did you use to make sure you didn't go through the thinwall on the neck of the intake manifold.

I'd love to hear more about how you ported the runners.

I have an LS1 with 241 Katech ( no flow numbers) ported heads with sodium filled LS6 valves. a 239/247 .623/.623 114 LSA cam shaft. I am running .040 thick head gaskets.

I really wanted over 425 RWHP on the dyno and had hopes of 385-90 ft lbs of torque. I'm currently spinning to 6800 RPM it flat-lined from about 6500 on up. hit 417 HP and 378 ft lbs of torque. after measuring my previous cold air intake i tossed it (83mm) put a bigger cone, and deleted the maf in favor of an SD tune.

I do plan to supercharge the car at some point I know the better flow i have now the better it will be then too. and have had fantasies of adding a 100 shot until i can fully afford the blower.
Old 09-06-2011, 11:30 PM
  #13  
TECH Senior Member
iTrader: (39)
 
LilJayV10's Avatar
 
Join Date: Apr 2007
Location: Evansville,IN
Posts: 9,309
Received 857 Likes on 610 Posts

Default

Originally Posted by 01ssreda4
People buy Snuggies (backwards robes) so your argument is null and void.
LMAO. I got one for xmas(no I didn't buy it)and my wife says the exact same thing! I still rock it playing COD when it's cold in the house. I'm not ashamed. Maybe I should be though.
Old 09-07-2011, 11:49 AM
  #14  
TECH Junkie
iTrader: (33)
 
LS1-450's Avatar
 
Join Date: Aug 2005
Posts: 3,783
Likes: 0
Received 9 Likes on 8 Posts

Default

Originally Posted by Y2K WS6
SWEET link .. and very nice job LS1-450 what throttle body did you use. I'm thinking maybe possibly a TBSS throttle body will work with an adapter/spacer on it? i am drive by wire

what precautions did you use to make sure you didn't go through the thinwall on the neck of the intake manifold.

I'd love to hear more about how you ported the runners.

I have an LS1 with 241 Katech ( no flow numbers) ported heads with sodium filled LS6 valves. a 239/247 .623/.623 114 LSA cam shaft. I am running .040 thick head gaskets.

I really wanted over 425 RWHP on the dyno and had hopes of 385-90 ft lbs of torque. I'm currently spinning to 6800 RPM it flat-lined from about 6500 on up. hit 417 HP and 378 ft lbs of torque. after measuring my previous cold air intake i tossed it (83mm) put a bigger cone, and deleted the maf in favor of an SD tune.

I do plan to supercharge the car at some point I know the better flow i have now the better it will be then too. and have had fantasies of adding a 100 shot until i can fully afford the blower.



Thanks,

-Used a Summit 85mm. Should mention that it was bought before Summit decided to way over price them. When purchased, it was in the $75 range.

-No precautions made; was just careful to watch & feel w/ hand how much material remained.

-As to "how were the runners ported"; don't. Just port match to the heads. Made this comment in the write up. Porting the runners will only slow the airspeed which will result in less air fed to the combustion chamber. From what I've measured, the only time to port runners is on engines w/ larger than stock 346 cu. displacement. Stock displacement just doesn't move a high enough volume of air to benefit from it. GM did a friggin' great job w/ LS6 runner design. This is also evident by the Holley "Street Warrior" fiasco that never happened because they could not improve on it.

-I don't rely on dyno's to accurately measure results from air movement mod's.. There are too many other variables that can effect the numbers. Look @ ambient air conditions against air speed (MAF) & air pressure (MAP). This will more accurately tell you how modifications have effected air flow. Of course, with an SD tune, only MAP is available for air measurement.
Old 09-07-2011, 01:50 PM
  #15  
TECH Junkie
iTrader: (33)
 
LS1-450's Avatar
 
Join Date: Aug 2005
Posts: 3,783
Likes: 0
Received 9 Likes on 8 Posts

Default

Y2K WS6,

Sorry, I try not to double post, but, thought more about your set up. So...


If your LS6 intake opening is stock, it is definitely holding back airflow. Would a$$ume that a cam w/ that much duration & then lift would build power up through 7K. The air restriction is also limiting the advantage of using sodium filled valves. Those valve are expensive & you aught to be getting your moneys' worth.

First, open up intake mouth either w/ 90mm TPS mod or to 85+mm @ home. Then, upgrade to a thicker walled pushrod like a Comp .105" wall 5/16". These two changes should get you all of the air available up through 7K on stock cubes.
Old 09-10-2011, 06:18 PM
  #16  
TECH Fanatic
iTrader: (7)
 
67SS&99SS's Avatar
 
Join Date: Feb 2004
Location: Georgia
Posts: 1,260
Likes: 0
Received 4 Likes on 3 Posts

Default

Originally Posted by 98z-28redcamaro
Has anybody used this? I would like to see a before and after dyno with a stock tb and a 92mm tb if anyone has tried it. Your still only able to get air through a 75mm hole, but it would be a good intermediary step when going from a LS1 or LS6 intake to the fast. The spacer is cheaper than having a stock one ported and there isn't any downtime associated with using it.
Old 09-10-2011, 07:00 PM
  #17  
The Scammer Hammer
iTrader: (49)
 
dr_whigham's Avatar
 
Join Date: Apr 2009
Location: Lafayette, LA
Posts: 6,707
Received 20 Likes on 16 Posts

Default

I made a thread about this very thing and I got completely **** on.... Well, at least Tony posted in my thread. That was kinda cool.

https://ls1tech.com/forums/generatio...-manifold.html
Old 09-10-2011, 08:28 PM
  #18  
TECH Fanatic
iTrader: (7)
 
67SS&99SS's Avatar
 
Join Date: Feb 2004
Location: Georgia
Posts: 1,260
Likes: 0
Received 4 Likes on 3 Posts

Default

Originally Posted by dr_whigham
I made a thread about this very thing and I got completely **** on.... Well, at least Tony posted in my thread. That was kinda cool.

https://ls1tech.com/forums/generatio...-manifold.html
Thanks for the link. I went straight to Tony's post. I liked what he had to say about the partial throttle opening. The engine will be able to take in more air with the bigger tb at the same throttle position as a smaller tb up to a certain point, then it will be like WOT with the smaller TB due to being limited by the opening size of the intake itself. So low-midrange is where you would expect see the improvement in hp/tq as well as throttle response. Since we spend most of our time in that range with street cars, it looks like it is definitely worth trying. Did you ever get around to trying it? This might be something I try out soon.
Old 09-10-2011, 08:57 PM
  #19  
The Scammer Hammer
iTrader: (49)
 
dr_whigham's Avatar
 
Join Date: Apr 2009
Location: Lafayette, LA
Posts: 6,707
Received 20 Likes on 16 Posts

Default

Never did get a chance. I dropped the coin on a P&P Epoxied TB & Chrs1313 Non-AC Ram Air instead. In the future I thought about a FAST 78 with a Shaner S3, or even a TPIS LS6 (already have LS6) and a 90 or 92mm TB.

I still think it's a good idea, and like someone else said, yeah, we have a 75-78mm TB, but you have to account for the blade and shaft. I think stepping to a 90 or 92 with a funnel would be an improvement.

The funnel is the key for velocity though.
Old 09-11-2011, 07:22 PM
  #20  
Launching!
Thread Starter
iTrader: (33)
 
Y2K WS6's Avatar
 
Join Date: Apr 2008
Location: Weston, WV
Posts: 262
Likes: 0
Received 0 Likes on 0 Posts

Default

My biggest gripe is that every thing i have found any where, throttle body prices are insane for ANY 90 mm throttle body even the stock GM ones. ... Looking into $$ per HP. this will be 500 for 10 HP or so. kind of annoying. really.

I would be doing all porting and polishing myself. so.that wouldn't be as much of an issue in the cost. just even the bare parts to start with are a lot of $$


Quick Reply: LS6 conversion to 90 MM



All times are GMT -5. The time now is 07:55 PM.