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How big of a cam is allowed with stock heads?

  • Thread starter Thread starter TDCRacing
  • Start date Start date
I have been following what you have been doing in the threads that were posted about E85 and setting aside all the cotroversy i'd like to hear how it turns out for you. So let me know.
 


im sure youll all hear about it come spring time, but for now im just sitting on everything that i have because its my DD and no one wants to work in the cold on a car that is going to get you all wet.

and i cant use the power either in the snow or the cold pavement.
 
Bio248 said:
im sure youll all hear about it come spring time, but for now im just sitting on everything that i have because its my DD and no one wants to work in the cold on a car that is going to get you all wet.

and i cant use the power either in the snow or the cold pavement.
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Amen to that, the cold sucks
 
TDCRacing said:
I want to be able to run 11.5's on a 75 shot. Maybe off of one? Just dont know how possible that is. I don't know of a lot of people that run faster than me on here that have an m90 setup. So it's hard to guess at what will work and what wont.I don't have a lot of experience on what part combo's people are using to go faster than 12's with a m90 setup is what i'm saying.
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If you just want mid 11's how about a Gen V, 125 shot, race gas, and some tuning? If that doesn't get ya there than port the heads some and call it good. Oh and have you thought about trying to raise the compression?
 
do you know someone that has done that before? I've got the tuning part down. And dont want to spray it more than i have to. 125 shot is the most i would want to go. And if i can get around those times WITHOUT the spray i would love that....with a m9o gen 5 setup that is.
 
Hmm mid 11's on a Gen V without spray is gonna be a big build but fully ported heads, a big cam, raised compression, race gas and slicks with a little bit of weight reduction (drop catback etc...) should hit mid 11's. But personally I'm cheap so I'd opt for the nitrous route :th_biggrin2:.
 


Yeah gunna be about 9.8:1 CR, Def. fully ported heads with oversized valves (thanks Bio) Thinking about the is4 cam wich is .600/.601 ,aluminum subframe and a cupple of other things.


Any one else on the cam suggestions?


DaWings33?
 
That'd be a wicked setup for sure. Just imagine what would happen if you added direct port nitrous to the list... can you say 10's... :th_king-evil:.
 
LOL... Well just go ahead and spend more of my money why don't ya.
 
yeah, those heads should work out well on your setup. i dont know how exactly you reach the .600/.601 lift the IS4 has, but do you really want to go that big?
 


IMO if you run fully ported heads and you are going to stay m90 the XPZ is your best bet if you dont want to go full XPZ a S1X or XP will also make good power. Stage 3 and 4 cams tend to like a larger power adder to be worth it. However if you do plan on running nitrous you may be able to get away with a bit bigger cam. The problem you run into here is that a M90 loves a intake bias cam and a nitrous setup will love a exhaust bias cam. So you will have to make that choice.
 
Bio248 said:
yeah, those heads should work out well on your setup. i dont know how exactly you reach the .600/.601 lift the IS4 has, but do you really want to go that big?
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If it will benefit me i do. I'm just not sure it will.
 
Dawings33 said:
IMO if you run fully ported heads and you are going to stay m90 the XPZ is your best bet if you dont want to go full XPZ a S1X or XP will also make good power. Stage 3 and 4 cams tend to like a larger power adder to be worth it. However if you do plan on running nitrous you may be able to get away with a bit bigger cam. The problem you run into here is that a M90 loves a intake bias cam and a nitrous setup will love a exhaust bias cam. So you will have to make that choice.
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Well you mentioned the m90 loves a intake biased cam and nitrouse loves an exhaused biased cam.


The Thing i don't get (and that may be because I don't understand it) is why let's say if i'm running nitrous is it better to ONLY have a cam that flows more on the exhaust side. Why not both? The way I think about it is what comes in must go out. And the same with what goes OUT will have to come IN.


I understand it may be a little different for nitrous. But lets talk about the m90. Why would I want a cam that has a higher valve lift then the exhaust does? Why not both?

Even if it is POSSIBLE to flow that amount it seems like i wouldnt be ABLE to or it seems like it would be easier to do so with a cam that has equal int/exh lifts.


From what you're saying about the M90 and the nitrous Dawings it seems like a high lift cam would be the way to go so the m90 and the nitrouse will be happy.


Would you agree?

Or would anyone agree?
 
Bio248 said:
i dont know how exactly you reach the .600/.601 lift the IS4 has
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What do you mean by that?



I plan on checking the clearance on the valve seals and if needed mill the guides down.



If that's what you ment.
 
i dont know how you get to the .601" lift that you need. longer valves? shorter pushrods? different retainers?

i have no idea.


either way the spray is going to have an effect. whether that effect is reduced or increased is dependant upon the cam choice you go with. true, the m90 loves an intake bias, but if youre going to be spraying that should take over command as being the bias you want.

because the intake or exhaust is biased in the lift characteristics, that is why it is helped. if there is no difference between intake and exhaust then there is no bias. i think you really need to figure out where you want to go with this before you make any big choices.

i wouldnt want to street an IS4. if i drove the car not everyday, then sure, but i drive my car EVERYDAY.



just for references, here is what i would do if i could go back in time and do it all over again:

l36 block/heads/lower/upper
IS3
ported heads to clear the IS3 w/bigger valves
JP double roller
HVIII
65# injectors
and to top it off, a CSC setup

it would be retarded mean and pull like crazy, especially with my 3.29s.
 
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Ok well as far as how do I plan on getting the clearance needed to run that much lift all that is needed is for the valve guides to be machined down so that you won't have any issues with the valve seal comming into contact with the retainer and causing oil ussage issues ect.Or you could possibly use modded retainers.But the only modded retainer kit that i have seen can only have lift up to .595 and that was the one from thrasher.


I do not know how much piston to valve clearance i will have but plan to use some clay to be on the safe side.I have not heard of any issues with PTV clearance with any cam although there has to be a limit somewhere.




I want a bad ass street build. What do you think would be some issues if i did run the is4 on the street?


What would be some issues that i might be seeing when running it on the street is what im asking.
 
i really cant tell you becasue i dont know how the cam acts. im just thinking that the valvetrain has got to take a beating with that high of lift. youd have to replace the dampner, chain, springs, etc. more often. ive only seen a few people run an IS4 and ive never really seen any crazy awesome times out of it.

if youre really looking for mid 11s, id stick with the tried and proven cams (XPZ, IS3, etc.).
 
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