Welcome to Mustang Evolution.
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07-28-2007, 12:33 AM
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#1
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supercharger????
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if you aint first you're last
Join Date: Mar 2006
City: mokena
State: Illinois
Posts: 119
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i was thinking about getting a supercharger for my cobra when i get back from iraq but i was told that b/c of all the mods i have done i have such a high compression ratio that ill keep blowing head gaskets with a supercharger. is that true? i was also told that i could get one but make sure not to go over like 8 or 10 psi. i would just like ur guys/girls input on the situation. thanks
here are most of my mods:  the engine is bored 40 over, heads, flatop pistons, 42lb injectors, cam, intake, full off-road exhaust, cai, msd ignition, smog pump delete, 1.7 roller rocker arms, thats all i can think of for now im sure im missing 1 or 2 things.
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car: 2000 v6 5-speed
1995 cobra svt
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07-29-2007, 12:53 AM
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#2
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Re: supercharger????
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too broke to race
Join Date: May 2007
City: Denham Springs
State: Louisiana
Posts: 953
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yes high comp. and boost don't mix. need to know your comp. first. you may have to run race fuel and have copper head gaskets
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 06 GT flowmasters, SCT2, CAI, 4:10 gears, ZEX 150hp wet shot. 11.76E/T at 115MPH & its my wife's car lol and the other muscle is a 1970
Chevelle SS 454
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07-29-2007, 01:48 AM
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#3
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Re: supercharger????
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Bob is Good.
Join Date: Jun 2004
City: Greenville
State: Texas
Posts: 5,171
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First and foremost, you need to find out what your compression ratio is. If it's over 9.5, I wouldn't put a blower on it. Even then, I probably wouldn't go over 8 psi just to play it safe.
On the other hand, nitrous and high compression work very well together. |
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07-31-2007, 04:28 PM
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#4
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Re: supercharger????
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if you aint first you're last
Join Date: Mar 2006
City: mokena
State: Illinois
Posts: 119
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then y is it that i see supercharged 94-95 mustangs all the time?? what makes the compression so high? is there anything i can do to lower it?
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car: 2000 v6 5-speed
1995 cobra svt
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07-31-2007, 04:52 PM
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#5
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Re: supercharger????
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I just lubricated on your foot!
Join Date: Feb 2007
City: Vicksburg
State: Mississippi
Posts: 783
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Probably because those supercharged cars you see have one of two things on them...either (1) they don't have nearly the list of mods that you do so they are running much lower compression on motor or (2) they have significantly built up internals made to handle the high compression...
Not to say that people don't do it, because quite a few do, but it's not usually a common thing to see guys run FI with a cammed car or with a car on spray...generally speaking (and I am sure some will disagree with me), but usually you see FI-ed cars only with that super/turbocharger and built up internals for running high boost OR you seem guys running cams and spraying...you usually don't mix the two...but then again, some people do it with great success...
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'05 GT - Borla Catback, Koni Adjustable Shocks/Struts, Hawk HP+ Brakes all around, Steeda Front Sway Bar & End-Links, Hoosier A6's on Enkei Race Wheels, Royal Purple Fluids
'07 F-150 Ext. Cab XLT Flareside - 5.4 Triton - Roush Dual Exit Cat Back
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07-31-2007, 05:01 PM
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#6
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Re: supercharger????
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if you aint first you're last
Join Date: Mar 2006
City: mokena
State: Illinois
Posts: 119
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my cobra has forged internals if that makes a difference
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car: 2000 v6 5-speed
1995 cobra svt
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07-31-2007, 05:31 PM
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#7
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Re: supercharger????
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Resident A$$hole
Join Date: Apr 2006
City: Columbus
State: Mississippi
Posts: 2,478
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You say your block is bored .40 over, which makes everyone assume you have increase the compression(which is what we would do). Now, you apparently have done quite a few mods, we would need to know what mods those are, and most importantly what compression(which has already been stated).
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01 Bullitt
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07-31-2007, 05:35 PM
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#8
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Re: supercharger????
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Resident A$$hole
Join Date: Apr 2006
City: Columbus
State: Mississippi
Posts: 2,478
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Actually a good cam with any kind of FI setup or nitrous is more common than you think. For the guys getting the most out of the combination a good supercharger cam can do wonders as can a turbo cam. They do not in the least cause any problems and actually make the combination run more efficiently. EX would be that a turbo car would run more duration on the exhaust than the intake to maximize the amount of air/exhaust leaving the cylinders to build boost faster, and for an SC car you don't want an overlapping cam because all that boost can actually blow the af mixture OUT of the cylinder during overlap.... Sorry to digress, but my point was just that a cam built for a specific application is something you do want to mix, especially if you want to maximize your combination. I think you mean high compression maybe? 
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01 Bullitt
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08-02-2007, 04:43 PM
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#9
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Re: supercharger????
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if you aint first you're last
Join Date: Mar 2006
City: mokena
State: Illinois
Posts: 119
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well the cam thats in my car says nitrous cam. so should i just go with nitrous or get a supercharger?? the guy i bought the car from said the car i built/setup for nitrous. but ill look into the whole supercharger thing and get my compression checked and then ill go from there.
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car: 2000 v6 5-speed
1995 cobra svt
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08-02-2007, 04:49 PM
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#10
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Re: supercharger????
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Resident A$$hole
Join Date: Apr 2006
City: Columbus
State: Mississippi
Posts: 2,478
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What are the specs on the cam?? And if you are getting another one, call COMP Cams or another RESPECTABLE company that makes cams. There is a black art to making cams and 99 times out of 100 only the people who have had YEARS of experience know what do to. There are several factors in getting the very best cam for your setup. Vehicle weight, gearing, auto or manual, forced induction or nitrous, your compression, and so on and so on. Like I said your best bet would be to complete your setup and call someone like Comp Cams and have them grind you a cam specifically for your setup.
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01 Bullitt
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08-02-2007, 04:50 PM
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#11
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Re: supercharger????
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Imma Ho...
Join Date: Aug 2004
City: Baton Rouge
State: Louisiana
Posts: 9,957
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Well, based on information relating to the 03/04 cobras...flat top pistons are 10.5:1 compression...with 17cc pistons being stock @ 8.5:1.
So, I would say you are somewhere around 9.5-10.5:1 compression. You could run boost on this setup, however you would need to keep the psi down to 8 psi max...and retard the timing some in order to be able to run street gas without detonation.
As for your last question, if you have a nitrous cam, I would go with nitrous over the S/C as your motor is setup to flow best for nitrous.
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08-02-2007, 04:55 PM
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#12
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Re: supercharger????
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Resident A$$hole
Join Date: Apr 2006
City: Columbus
State: Mississippi
Posts: 2,478
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I'm totally confused... The 5.0 and the modulars don't have that much in common, especially combustion chamber size, piston size, and so on. When did he say what cc dish pistons he had??
I'm probably confused on your post... so  My bad if I am 
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01 Bullitt
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08-02-2007, 05:04 PM
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#13
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Re: supercharger????
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Imma Ho...
Join Date: Aug 2004
City: Baton Rouge
State: Louisiana
Posts: 9,957
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Quote:
Originally Posted by bluestang1724
here are most of my mods: the engine is bored 40 over, heads, flatop pistons, 42lb injectors, cam, intake, full off-road exhaust, cai, msd ignition, smog pump delete, 1.7 roller rocker arms, thats all i can think of for now im sure im missing 1 or 2 things.
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I was basing my comments losely on what I know about the 03/04 cobra motors. I know flat tops in a cobra are 10.5:1, so that is why I said he is probably 9.5-10.5:1. I am also basing them on the assumption that when he says flat top pistons he is refering to a 0cc dish.
I realize they are different motors and all, however piston dish is going to apply to all motors equally. The more dish, the less compression. It is with that statement that I based my comments.
So, I guess to generalize my comments even further...with flat top pistons, the C/R is probably high...therefore boost would have to be kept down.
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08-02-2007, 05:06 PM
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#14
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Re: supercharger????
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Resident A$$hole
Join Date: Apr 2006
City: Columbus
State: Mississippi
Posts: 2,478
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Gotcha, I just read your post wrong... I was getting the whole dish and lower compression part... but stock pistons are also flattop in a 5.0... Plus we don't know if the block has been decked and/or the heads.. Too many darn variables.
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01 Bullitt
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08-02-2007, 05:08 PM
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#15
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Re: supercharger????
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Imma Ho...
Join Date: Aug 2004
City: Baton Rouge
State: Louisiana
Posts: 9,957
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Yeah....but did my brain dump anyhow...made me feel important for a couple seconds. 
And if stock is flat top...the C/R should be around 9.5 or 10:1...I think that is what they came with stock....with the caveat of what else has been done.
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08-02-2007, 05:12 PM
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#16
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Re: supercharger????
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I just lubricated on your foot!
Join Date: Feb 2007
City: Vicksburg
State: Mississippi
Posts: 783
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on a 3V modular, the factory C/R is 9.8:1 which limits boots to around 8-10psi on stock internals...
I would guess his C/R is somewhere in that range, and if the motor is potentially built, then i would think he could run more boost than that? maybe 14-16psi?
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'05 GT - Borla Catback, Koni Adjustable Shocks/Struts, Hawk HP+ Brakes all around, Steeda Front Sway Bar & End-Links, Hoosier A6's on Enkei Race Wheels, Royal Purple Fluids
'07 F-150 Ext. Cab XLT Flareside - 5.4 Triton - Roush Dual Exit Cat Back
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08-02-2007, 05:17 PM
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#17
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Re: supercharger????
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Imma Ho...
Join Date: Aug 2004
City: Baton Rouge
State: Louisiana
Posts: 9,957
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The forged internals could hold it, but, it would be detonation you would have to worry about. With high compression and high boost, the octane requirements go up quickly...or else you have to start pulling a lot of timing...which would start negating the benefit of running the higher boost as it will decrease your power output.
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08-02-2007, 05:18 PM
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#18
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Re: supercharger????
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I just lubricated on your foot!
Join Date: Feb 2007
City: Vicksburg
State: Mississippi
Posts: 783
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Isn't that what 100+ octane race fuel is for? 
__________________
'05 GT - Borla Catback, Koni Adjustable Shocks/Struts, Hawk HP+ Brakes all around, Steeda Front Sway Bar & End-Links, Hoosier A6's on Enkei Race Wheels, Royal Purple Fluids
'07 F-150 Ext. Cab XLT Flareside - 5.4 Triton - Roush Dual Exit Cat Back
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