MS3 and 42lb injectors & stock heads
08-12-2011, 04:51 AM
#1
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MS3 and 42lb injectors & stock heads Hey guys,
I do A LOT more reading, subscribing, and searching on the forums than anything else here, as I've been debating on a setup the last few months. So I finally picked one, and have everything set up to go with just a few questions.
What I have now is the MS3 cam (package), LS7 lifters, LS6 ported OP, double roller TC, 7.400" pushrods, FAST92/92, stock 853 heads, 4k stall, and 3.73s. My question is, with a cam of this size, how beneficial would it be to upgrade the injectors? I'm not one that's into the hype of dyno numbers, but I see a lot of MS3 owners that have upgraded to 42s. Search after search doesn't bring up whether its necessary and/or how beneficial it is.
Also, what about the stock fuel pump? Is it going to provide enough pressure and volume to keep the 42s pulsating up to par? I'm moreso leaning towards upgrading the fuel pump and injectors, for the sake of nitrous and the 150 shot I'll be taking off the rail. Is it a must or just added insurance with that being said?
Then the factory heads. Sure, I know I'll see a lot more gain out of going with some better better heads, but are the 853s going to be restrictive in the powerband? For example, the stock LS1/EGR intake dies off somewhere above 5k rpm, so the MS3 and factory 2000 style intake is a horrible combo, restricting the powerband. Thus, being the need for upgrading to atleast a LS6 intake (or the FAST 92/92 like I did). Are the heads the same way? My searches don't show much specific information for this question, so I sit here asking you guys.
I do A LOT more reading, subscribing, and searching on the forums than anything else here, as I've been debating on a setup the last few months. So I finally picked one, and have everything set up to go with just a few questions.
What I have now is the MS3 cam (package), LS7 lifters, LS6 ported OP, double roller TC, 7.400" pushrods, FAST92/92, stock 853 heads, 4k stall, and 3.73s. My question is, with a cam of this size, how beneficial would it be to upgrade the injectors? I'm not one that's into the hype of dyno numbers, but I see a lot of MS3 owners that have upgraded to 42s. Search after search doesn't bring up whether its necessary and/or how beneficial it is.
Also, what about the stock fuel pump? Is it going to provide enough pressure and volume to keep the 42s pulsating up to par? I'm moreso leaning towards upgrading the fuel pump and injectors, for the sake of nitrous and the 150 shot I'll be taking off the rail. Is it a must or just added insurance with that being said?
Then the factory heads. Sure, I know I'll see a lot more gain out of going with some better better heads, but are the 853s going to be restrictive in the powerband? For example, the stock LS1/EGR intake dies off somewhere above 5k rpm, so the MS3 and factory 2000 style intake is a horrible combo, restricting the powerband. Thus, being the need for upgrading to atleast a LS6 intake (or the FAST 92/92 like I did). Are the heads the same way? My searches don't show much specific information for this question, so I sit here asking you guys.
08-12-2011, 05:16 AM
#3
My suggestion would have been to buy an ls6 intake and a set of 243 heads over the fast. You will definetly be over the suggested 80% duty cycle on the stock injectors and will most liekly run out of fuel up top. You wotn per se GAIN power but you will be able to make the power the cam is capable of. The stock fuel pump should handle your power but you will definetly have to upgrade if you chose to spray.
08-12-2011, 05:39 AM
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Well I bought fast intake and UD pulley used, from a buddy, as he went with the LSXR, and gamme both of those for $500, so I didn't really want to pass it up. From what you're saying, I think I might be better off doing the fuel system and heads before I put it all together. If I'm going to be max'ing out the factory injectors, just to see the cam perform "up to par", then i'd probably be stupid NOT to upgrade. 243s would probably be the best to meet my budget. A lot of you guys are running the Racetronix FP I see, haven't heard of much complaint about it. Guess its time to talk to some vendors...
08-12-2011, 06:01 AM
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could probably go #36's but #42's will give you a bit of extra room to move with and less stress/usage of the injectors potential so to speak if you get my drift. That's from what iv been told anyway.
08-12-2011, 06:05 AM
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Hmm, that's pretty interesting. If there's little cost difference, it may behoove me to go with 42s I would imagine. Come to think of it, i'd probably much rather do so, because of my plans to spray on top of it.
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08-12-2011, 03:49 PM
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I would definitely upgrade heads. I currently run a ms3 cam, ported 90/90 and a set of tsp stage 1 243s with ls3/ls7 42 lb injectors and it runs its bag off. Just make sure you have some gear in the car because mine still has 3.42s and its pretty soft down low until you hit 4000 rpms.
08-12-2011, 07:30 PM
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I don't think that you will gain much by putting a stock 241 head on the car vs that 853 on it now. If they were ported, you will benefit from it, but replacing a head with another stock head wont do much. 243's would be the way to go if you were looking at stock replacement. 42# inj so you have room to grow.
08-13-2011, 04:40 AM
#11
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08-13-2011, 04:52 AM
#12
my injectors were real close to maxed out with just the ms4, i dont think we could spin it past 5800 rpm, was kinda awhile ago ,but 5800 is far from where the ms4 makes peak power ,yeah for sure go 42lbs, your going to wanna spray the car sooner or later lol
08-13-2011, 05:03 AM
#13
the 853s are not the best head but your not gonna gain anything by swaping to 241s , stock 243s would help, but imo i would get the heads from tsp, just when it comes time to order heads make sure they know the cam you have, i read a thread a lil while back ,were a member did a complete rebuild, and when he got his heads he didnt tell them the huge cam he was running and well do i need to say what happend next?
