stock 241s/243
10-28-2009, 12:14 PM
#1
stock 241s/243 how much would stock 241s add? and 243s? to my current setup. i really dont want to add top of the line heads since im going to be spraying alot of power. also how much would a good budget job cost and add power wise?
10-28-2009, 12:21 PM
#2
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well you basically have 241s stock...or a very similar variant.
the 243s will flow a small amount better and increase compression a little.
with your cam...i'd think 15-20hp would possible
aftermarket heads work fine with spray too...not sure why you use that as your decision maker.
the 243s will flow a small amount better and increase compression a little.
with your cam...i'd think 15-20hp would possible
aftermarket heads work fine with spray too...not sure why you use that as your decision maker.
10-28-2009, 12:27 PM
#4
i have 853 heads. the reason i dont want to spend 2500 on say afrs or trick flows becuase why should i spend that much money if im going to be spraying a 150 shot and maxing out the motors potential. if i get the good heads i would spray less and still be making the same power just with more money. when the motor gets higher mileage and i forge it then i would get the good heads becuase i can spray more and add more power.
10-28-2009, 12:35 PM
#5
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you're joking right?
STOCK 243s won't gain you 1/2 that!! maybe some stage 2 or 3 ported heads...but not stock.
i see your point about spending the money on heads, when you can gain it from spray.
but i guess i don't see what you mean about "maxing the motor out".
400rwhp + 150hp shot or 450rwhp + 150 shot.....which seems better to you?
and its possible to gain more with that 150shot if the heads work well with the nitrous.
something like some ported 5.3s would build more compression than the ls6 heads, and flow much better...both should make the spray more efficient.
10-28-2009, 12:36 PM
#6
This is not correct. 799s are the same as 243s not 241s. And 799s are the newer version of 243s.
10-28-2009, 12:38 PM
#7
you're joking right?
STOCK 243s won't gain you 1/2 that!! maybe some stage 2 or 3 ported heads...but not stock.
i see your point about spending the money on heads, when you can gain it from spray.
but i guess i don't see what you mean about "maxing the motor out".
400rwhp + 150hp shot or 450rwhp + 150 shot.....which seems better to you?
and its possible to gain more with that 150shot if the heads work well with the nitrous.
something like some ported 5.3s would build more compression than the ls6 heads, and flow much better...both should make the spray more efficient.
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10-28-2009, 01:37 PM
#8
you're joking right?
STOCK 243s won't gain you 1/2 that!! maybe some stage 2 or 3 ported heads...but not stock.
i see your point about spending the money on heads, when you can gain it from spray.
but i guess i don't see what you mean about "maxing the motor out".
400rwhp + 150hp shot or 450rwhp + 150 shot.....which seems better to you?
and its possible to gain more with that 150shot if the heads work well with the nitrous.
something like some ported 5.3s would build more compression than the ls6 heads, and flow much better...both should make the spray more efficient.
The 243 or 799 heads will raise compression as well. The valves are unshrouded and has a dual quench pad design vs the 241s do not. I think 243s or 799s right out of the box are awesome budget heads, especially since you could get them at the junk yard for dirt cheap.
10-28-2009, 02:15 PM
#9
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10-28-2009, 02:55 PM
#10
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Quote:
Originally Posted by wildta
the 243,z06 heads ported are good for about 50 hp,but raise compression.
you're joking right?
STOCK 243s won't gain you 1/2 that!! maybe some stage 2 or 3 ported heads...but not stock.
He did say ported not stock.
Originally Posted by wildta
the 243,z06 heads ported are good for about 50 hp,but raise compression.
you're joking right?
STOCK 243s won't gain you 1/2 that!! maybe some stage 2 or 3 ported heads...but not stock.
He did say ported not stock.
10-30-2009, 10:04 AM
#11
243s add about 14hp on the engine dyno. CNC ported PRC LS6 stage 1 heads add $40 hp for $1000.
We also offer cnc ported 241 heads for $700 that include a 2.02/1.55 valve combo. While they don't work nearly as well as a ported LS6, they'll move mid 280s cfm & add 30+hp for $700! Next to a set of 243s that cost $500 with stock valves, it might be something to consider!
We also offer cnc ported 241 heads for $700 that include a 2.02/1.55 valve combo. While they don't work nearly as well as a ported LS6, they'll move mid 280s cfm & add 30+hp for $700! Next to a set of 243s that cost $500 with stock valves, it might be something to consider!
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Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
10-31-2009, 01:19 PM
#12
243s add about 14hp on the engine dyno. CNC ported PRC LS6 stage 1 heads add $40 hp for $1000.
We also offer cnc ported 241 heads for $700 that include a 2.02/1.55 valve combo. While they don't work nearly as well as a ported LS6, they'll move mid 280s cfm & add 30+hp for $700! Next to a set of 243s that cost $500 with stock valves, it might be something to consider!
We also offer cnc ported 241 heads for $700 that include a 2.02/1.55 valve combo. While they don't work nearly as well as a ported LS6, they'll move mid 280s cfm & add 30+hp for $700! Next to a set of 243s that cost $500 with stock valves, it might be something to consider!
10-31-2009, 02:29 PM
#13
36lbs injectors should be an option your looking at. The cam I am running is very similar to the MS3 and I had my 243s milled .005, cnc and i kept the 64CC chambers and I did not have to fly cut. The specs on my cam are 235/241 614/614. The ms3 is 237/242 603/609.
11-02-2009, 04:17 PM
#16
I would do the 42# injectors if the fuel pump/mods supports them. You will need somewhere around 58lbs of fuel pressure to support those injectors. I am sure that the stock pump will not support that. You will have to upgrade your fuel pump but also do you need those injectors, I mean the guys that I know using those are guys with 600rwhp and up. Stock the C5 ZO6 is supporting 405 bhp with 28# injectors and I am supporting 450+ rwhp with 36# injectors.
11-02-2009, 07:46 PM
#17
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So 36lb is where the line is drawn? 450 is about my goal anyway. So with injectors I am guessing you have to match them to the application? Is it imperative to run them at a certain duty cycle?
11-02-2009, 10:04 PM
#18
Again it depends on your application if it s NA on a 5.7L yes I would say 36# injectors are about right because your stock bottom end is about done at or around 500 rwhp.
Very important.
You never want to run an injector more than 80% of their duty cycle. Most injectors will go static at about 92% of duty cycle. The lower the duty cycle you are running and still attaining your hp needs the better. Now this is not to go out and buy the biggest injectors you can find, because th application has to be able to support it, hense I use 36# injectors in my C5 LS1. If your injector goes static it means that the injector no longer has the ability to control the delivery of fuel to the engine (its pumping fuel constantly into the cylinder) and it is along for the ride. Your injectors should never go static
http://www.injector.com/injectorselection.php
That link will help you select an injector for your HP needs.
Good Luck
You never want to run an injector more than 80% of their duty cycle. Most injectors will go static at about 92% of duty cycle. The lower the duty cycle you are running and still attaining your hp needs the better. Now this is not to go out and buy the biggest injectors you can find, because th application has to be able to support it, hense I use 36# injectors in my C5 LS1. If your injector goes static it means that the injector no longer has the ability to control the delivery of fuel to the engine (its pumping fuel constantly into the cylinder) and it is along for the ride. Your injectors should never go static
http://www.injector.com/injectorselection.php
That link will help you select an injector for your HP needs.
Good Luck
11-02-2009, 10:34 PM
#19
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243s add about 14hp on the engine dyno. CNC ported PRC LS6 stage 1 heads add $40 hp for $1000.
We also offer cnc ported 241 heads for $700 that include a 2.02/1.55 valve combo. While they don't work nearly as well as a ported LS6, they'll move mid 280s cfm & add 30+hp for $700! Next to a set of 243s that cost $500 with stock valves, it might be something to consider!
We also offer cnc ported 241 heads for $700 that include a 2.02/1.55 valve combo. While they don't work nearly as well as a ported LS6, they'll move mid 280s cfm & add 30+hp for $700! Next to a set of 243s that cost $500 with stock valves, it might be something to consider!
11-02-2009, 10:59 PM
#20
An injector that is too large can cause resolution problems and make it tough for you to nail down idle quality/stability or pass emissions. Basically, changes from one step to the next (cell to cell in the fuel map) are large enough that you can't get a consistant idle. Not a problem in a racecar, but might not be ideal for a daily driven hotrod. You probably would not notice any difference between 36lb and 42lb injectors, but you don't want to go higher than that.
Everything 02*C5 stated above about duty cycle is spot on.
Everything 02*C5 stated above about duty cycle is spot on.