Low compression forged ls2
03-02-2011, 04:20 PM
#1
On The Tree
Thread Starter
iTrader: (1)
Join Date: Aug 2009
Location: Detroit,MI
Posts: 150
Likes: 0
Received 0 Likes
on
0 Posts
Low compression forged ls2 I'm getting ready to forge my ls2 I want it to have low compression thinking 8:5:1 so I can run the most boost and make the most power I can using pump gas and a alky kit.What are your thoughts?I don't think because of the low c r it will be a dog out of boost if I want more power then ill get her into boost but I don't think it will be bad anyways I've owned two grand nationals which were low c r v6's and out of boost they were not bad to me so your thoughts
03-02-2011, 05:12 PM
#3
On The Tree
Thread Starter
iTrader: (1)
Join Date: Aug 2009
Location: Detroit,MI
Posts: 150
Likes: 0
Received 0 Likes
on
0 Posts
O sorry about that its a 98 ta al ls2 with Turbo cam and springs 4l60 kytp truck manifold kit tc78 my goals are about 900 rwhp when I change the Turbo to a gt91 and the transfer will be a powerglide.I want to run 880's or so street stop car if there's any other info u need just ask me
03-02-2011, 05:47 PM
#7
TECH Fanatic
iTrader: (59)
Join Date: Jan 2007
Location: Pittsburgh,Pa
Posts: 1,736
Likes: 0
Received 0 Likes
on
0 Posts
Track or street build?
If both ide go 9.5 to 1 like i did with my LS2 364 turbo set up!I put down 650 rwhp on a small 10psi setting for the street and can go to 20to 25 for the track with meth if i ever felt the need,which i dont lol . 8.5 to 1 is just way to low IMO. Turbos will be a dog to spool up with that low of a CR unless your planning on a VERY high stall convertor which ='s more heat to the tranny IMO
If both ide go 9.5 to 1 like i did with my LS2 364 turbo set up!I put down 650 rwhp on a small 10psi setting for the street and can go to 20to 25 for the track with meth if i ever felt the need,which i dont lol . 8.5 to 1 is just way to low IMO. Turbos will be a dog to spool up with that low of a CR unless your planning on a VERY high stall convertor which ='s more heat to the tranny IMO
Trending Topics
03-02-2011, 06:35 PM
#8
On The Tree
Thread Starter
iTrader: (1)
Join Date: Aug 2009
Location: Detroit,MI
Posts: 150
Likes: 0
Received 0 Likes
on
0 Posts
I disagree grand national v6's are very low c r and I was spoiling a 70mm Turbo with only a 3800 stall I'm just trying to find a basis on why people think it will be such a dog speed Inc sells a boost block that's 8:5:1 comp and the made 995rwhp with it I think they know there stuff if its only making 350hp it will still spool the hell out of any Turbo smaller than a 98mm
03-02-2011, 06:40 PM
#9
On The Tree
Thread Starter
iTrader: (1)
Join Date: Aug 2009
Location: Detroit,MI
Posts: 150
Likes: 0
Received 0 Likes
on
0 Posts
It will be a street strip car with a lot of strip time I'm really not concerned with instant boost if I was I would have a roots blower around town just driving a 8:5 comp ls2 off boost should still have enough grunt to pass people
03-03-2011, 06:38 AM
#13
Teching In
Join Date: Apr 2009
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
8.5 means you have the potential for big boost on pump gas without having the complication of meth etc. Which to me is a big bonus.
Personally I like much lower so can see 30psi on pump fuel with no AI. Boost = Torque. Not like thats ever lacking on a LS2...!
Ive ran as low as 7.2:1 before on engines as small as 1.4 litres, and in my eyes it doesnt make much difference to off-boost low rpm performance, not as much as a long duration cam or huge head ports does anyhow.
Personally I like much lower so can see 30psi on pump fuel with no AI. Boost = Torque. Not like thats ever lacking on a LS2...!
Ive ran as low as 7.2:1 before on engines as small as 1.4 litres, and in my eyes it doesnt make much difference to off-boost low rpm performance, not as much as a long duration cam or huge head ports does anyhow.
03-03-2011, 07:53 AM
#15
Teching In
Join Date: Apr 2009
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
03-03-2011, 09:30 AM
#17
How much power and how fast are you looking to go. Setup with the procharger was 10.0/1 Ran well on pump and Meth. 13psi and went 9.8@141mph.
My new setup for the Turbo build I am doing will be more like 9.8/1 and plan on seeing 15 psi regularly. a properly setup meth system with the a car that is properly tuned so that IF you loose the Meth it pulls timing and saves the motor. I know MrBig or whatever his name is had a Meth failure doing a Mile pull and having it tuned properly pulling timing when it saw the IATs go up saved his motor
These cars like CR even on boost. And with a forged motor there is no reason to go as low as 8.5/1 If you want to stay lower on the CR the lowest I would go it 9.0/1 but 9.2-9.6 is what I would shoot for
My new setup for the Turbo build I am doing will be more like 9.8/1 and plan on seeing 15 psi regularly. a properly setup meth system with the a car that is properly tuned so that IF you loose the Meth it pulls timing and saves the motor. I know MrBig or whatever his name is had a Meth failure doing a Mile pull and having it tuned properly pulling timing when it saw the IATs go up saved his motor
These cars like CR even on boost. And with a forged motor there is no reason to go as low as 8.5/1 If you want to stay lower on the CR the lowest I would go it 9.0/1 but 9.2-9.6 is what I would shoot for
03-03-2011, 05:45 PM
#18
On The Tree
Thread Starter
iTrader: (1)
Join Date: Aug 2009
Location: Detroit,MI
Posts: 150
Likes: 0
Received 0 Likes
on
0 Posts
Nobody is giving me any basis on why its too low and wont work well like stated earlier in the post with low c r u have the potential to run night boost numbers on pump gas what do you mean it will be lazy when boost comes on it will hit like a freight train and the ally is just for a safeguard nobody is relying on it my low c r motor will do just as good as a higher c r motor until I hear a good reason y ill stick with it