4DRUSH

iTrader: (2)

Go for it and let us know how you made out.


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Frametwista

iTrader: (1)

I surely will but I still want to know some real world experience from the people who say the c r will be to low and wont be good as a higher c r would

dschmittie1

iTrader: (64)

I think the idea of the low CR is an older idea that allows the use of more timing and more boost. The newer stance on things is that CR is being raised and we might be running less timing but it really helps Spool a turbo sooner. This in turn will help at the track.

Lets take a look at guys like Fireball and Phil Thomas that are running near 10:1 on motors that see 40psi. Granted they are in a totally different league than we are talking here but you can see where I am going with this. The Higher CR is allowing them to make more power under the curve and helping the car get down the track faster.

Everyone alway looks at peak numbers but when you make more power sooner but maybe a little less up top you will see the car run a better number.

Ask guys like Pro Stock John that had build turbo and blower motors years ago when the LS stuff was new and they had CR around 8.5/1 most of them will tell you they would never build another motor with CR that low.

Frametwista

iTrader: (1)

OK thäts what I was waiting to hear a little more info on the thinking the c r is too low.in my case I really think it would run hard still on low comp you know 800hp is 800hp but I really think it will be safer at 30psi than a high com motor I think you can make big power both ways it just a little safer when u lower the c r

westtexasbuff

iTrader: (40)

LOL.... 30psi with 4 bolt heads... good luck.

tomz28

iTrader: (20)

dont listen to these guys my car is 8.7 to 1 and its a street car ( see sig) drive it to work when i can. still will run 9s all day long on low boost . its getting tuned for the new injectors and the 3bar next week. but 8.80s is one hell of a goal
but 8.7 is working out very well for me.
hope this helps

Frametwista

iTrader: (1)

First of all who said I would be using six bolt heads you shouldn't assume cause your wrong eel block converted to six bolt so I will be using six bolts thank u very much and I hear u man I know it will work and work good you are another example of it working so some of these guys are just wrong with their thinking the c r is too low I keep asking too low to do what be fast? I don't think so but the one post gave at least a little back up info to it being old tech but it still holds true I would rather be able to boost a low CR motor to 30lbs than boost a higher CR motor to 20 I think my 30 will be faster than the 1 point of comp but I really appreciate the replys Guy d

Frametwista

iTrader: (1)

Typing on this Droid sucks sorry bout the spelling that was erl block four bolt know going to six bolt ls6 intake powerglide trans 91mm t4 forged piston rods stock crank 120lb injury dual fuel pumps a2a cooler should do well 880's here I come not decided yet on heads

dschmittie1

iTrader: (64)

In the end you can do what you/your engine builder/tunner thing is best for your goals. I think my 9.8:1CR 347ci motor will go an 8.9 on 18lbs in good air.

I know on one of my old Procharged setups I went from 9.2/1CR to 9.9/1 and it made a huge difference in how responsive the car was

If you want to stay on the lower end of things I would build your motor for 9.0/1 That still is what most of is would consider LOW but is a little higher than what you where thinking. Still gives you the added benifit of the lower CR for preventing detionation.

Frametwista

iTrader: (1)

C I really don't care about responsiveness that more of a mainly street car thing as long as when I go full throttle and that bitch pushes me in the seat so hard I can't sit up I'm happy I could care less about whipping in and out of traffic and the car being responsive I believe even off boost a low comp ls2 will beat about 90% of the regular cars out so being responsive is kind of a mute point when u r racing its wide open if it doesn't respond then there's something else wrong

dschmittie1

iTrader: (64)

I still think a higher compression motor will help that thing spool faster for that WOT burst on the street.

If having higher CR didn't help at the track why would track only guys be pushing there CR higher and hight

Frametwista

iTrader: (1)

They are on super octane race gas I'm taking pump two different beasts that's why they are pushing high c r and they also want every single tenth every possible advantage not me 880' s is all I want not every last ounce of power I can get just a lot on pump and meth

dschmittie1

iTrader: (64)

To each his own then. I Will let you know how my pump gas and Meth 347 does on my quest for 8.9's with its high CR.

I guess the thing I don't get it you come in asking if it is a good idea and several people say to raise it. I am not saying raise it way up there I just wouldn't go as low as 8.5/1 So several people say raise and one says low work(as we all know it does because that is what everyone has been doing for years) I think you will go faster with less boost with a higher CR. Then you have the ability to some day go. Why not through a race fuel to in it and turn the boost up even higher and go even faster.

The higher CR is gonna help that 364 spool a 91mm turbo also.

Frametwista

iTrader: (1)

I also don't really care about instant spoiling like I stated earlier in the post but ill state. It again that's one of the things I like about turbos is some lag I'm on a ten in slick I don't want the power to hit quick I like how it ccomes. On sneaky and. All of a sudden bam

Frametwista

iTrader: (1)

My low CR will whoop u LOL UK

Frametwista

iTrader: (1)

First of all I didn't ask was it a good idea if u would of read my open I asked what did u guys think about it get your facts straight I wanted to hear different opinions and the reason behind them which I got to some extent

Frametwista

iTrader: (1)

That was read my original post I have no doubt that higher CR would help spool the Turbo but you can still spool it with low CR Meth is also a lot cheaper than race gas and that would be interesting to see if a low CR setup would be slower than a high CR setup pushing low boost I don't think your giving Turbo power enough credit I think boost gives more power than comp imo

dschmittie1

iTrader: (64)

You have more CI than me and being that you are going with a 6 bolt head I am sure your heads will flow alot more than my little buget build 347

I am not doubting the power of a turbo. Why else would I have sold off all my procharger stuff to go Turbo. I would rather have more power with less boost as it is easier on parts and will help my motor last longer.

I think you have your mind set on running a lower CR and your not really hearing what is being brought to your attention.

I guess first thing is you start your thread with wanting opinions on a low CR with no details of the set up. Desired power level and goals. For most of the builds 500-700 hp in hp that CR is too low. For your build and wanting to run 20+ psi I wouldn't go as high with the CR. But I also don't think it will take 20+ psi to run a 8.8

Since you will likely have a very good flowing head and a power glide. You shouldn't have much of a problem reaching your goals. I just think raising your CR will help not hinder you

Frametwista

iTrader: (1)

I did state in my earlier post what my goals were so I don't know what u r talking about.I did take heed to what people brought to my Attn about higher CR IMO I think higher CR in the chamber with Turbo boost is harder on the motor than low CR and Turbo boost so it is what it is.I want to run big boost on pump that's my goal so I can be set on kill all the time so high CR big boost equals race gasexpensive crusin on that thus the need for low CR

westtexasbuff

iTrader: (40)

Why the **** ask for advice, then shoot everyone down who gives it to you? This guy is such a tool.