He said my compression is too high at 10:1 to go forced air but I would be safe with a 75HP shot of nitrous...Any ideas why one is safer than the other? Is this something I could get around with a tune? I mean and still supercharge? Thx in adv.
My engine manufacturer says no to forced air and yes to nitrous?
- Thread starter Pokageek
- Start date
Roland69
Sergeant Tangnet
he's right you would need to lower your compression a point or 2 to run forced air. a 75 shot of nitrous is almost safe on most stock motors. I know someone who runs a 95 shot on his stock 5.0 with over 200,000 km's and he's filled the bottle up probly 20 times and it's still running strong.
BlueOvalStangGT
Active Member
Motors with forced induction need less compression to prevent detonation. Hence 03 cobras having 8.5:1 compression. Nitrous on the other hand gets along great with higher compression. A 75 shot on a motor with you compression will probably make ~100hp. Take the LSX engine line, you never see the F-Body guys runnning blowers/turbos because their compression stock is over 10:1. However, those motors are complete beasts once a shot of nitrous is installed. If you want to go turbo/blower you need to lower your compression back to stock or less(I vote stock unless your running ALOT of boost, like 18+psi) OR keep the boost low(like 5-6 psi). However, your car would make MUCH more power with a 100 shot(if you have the fuel). I vote going with nitrous
Roland69
Sergeant Tangnet
BlueOvalStangGT
Active Member
Roland69
Sergeant Tangnet
sometimes I know what I'm thinking but can't seem to type it down the way I thought it would sound lol.
5.0_GT_kid
20+ Year Stangneter 
Ok. Sounded like nitrous is a definite winner. I guess I would go to a 255 fuel pump on that..24#'rs safe? Add anything else? Thanks guys.
BUT..on the other hand ..if I went with a low boost of 4.5-5psi and intercooled for safety, you guys think that will yield nice power gains and be safe too?
What blower would you recommend will put out that low of boost?..or would that be a pulley switch? I also have hypercraptic pistons but tune will make that safe.
BUT..on the other hand ..if I went with a low boost of 4.5-5psi and intercooled for safety, you guys think that will yield nice power gains and be safe too?
What blower would you recommend will put out that low of boost?..or would that be a pulley switch? I also have hypercraptic pistons but tune will make that safe.
A 10:1 motor will run PERFECTLY fine with 10 lbs of boost on pump gas. You may not be able to run 38* of total timing, but somewhere in the mid to upper 20's would work fine.
You could also get a camshaft that's too aggressive to run on 10:1, 10 lbs., and pump gas, but it would have to have ton of dynamic compression....
If a motor will run on nitrous, it'll run with force induction. Period.
Joe
You could also get a camshaft that's too aggressive to run on 10:1, 10 lbs., and pump gas, but it would have to have ton of dynamic compression....
If a motor will run on nitrous, it'll run with force induction. Period.
Joe
Yobi1Kanobi
Member
- Apr 9, 2003
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stick with the juice and a good tune/ retard timing while spraying with a retard switch and you will be better off. I ran nitrous threw my stock motor with HCI for years with out too much trouble. I ran about a 150 shot but with the 100 shot it is fairly safe. Plus its cheaper and you only use it when you need it.
"A 10:1 motor will run PERFECTLY fine with 10 lbs of boost on pump gas. You may not be able to run 38* of total timing, but somewhere in the mid to upper 20's would work fine."
Not to over-analyze but you guys are making this a great discussion..Almost sounds like it is the HP that is the measure of safety with the compression. 75-100HP might be like 4psi or something. I think it is making more sense if correct.
Running less timing..Is that defeating the purpose or makiing the car slower?..back to nitrous as making more sense if so.. or more cost effective.
Not to over-analyze but you guys are making this a great discussion..Almost sounds like it is the HP that is the measure of safety with the compression. 75-100HP might be like 4psi or something. I think it is making more sense if correct.
Running less timing..Is that defeating the purpose or makiing the car slower?..back to nitrous as making more sense if so.. or more cost effective.
Black95GTS
Active Member
Pokageek said:
A power adder is a power adder. The whole point of either of them is to stuff in more O2, which allows you to burn more fuel, which is what makes more power.
Compression Ratio is the ratio between the volume above the cylinder at bottom dead center to the bottom above the cyclinder at top dead center.
NOS works "better" with higher C/Rs because it carries more Oxygen then air does. Therefor you need to "force" less NOS into the combustion chamber then you would need to force an equivalent amount of air to get the same amount of power.
Nitrous is MUCH more efficient at adding oxygen into the combustion chamber then either a turbo or a blower. Plain and simple. Air is only 21 percent oxygen. N2O is 36 percent oxygen. More oxygen = more fuel = more power.
That being said, you can run either to great effect depending on the tune and supporting hardware. You have to pull timing and increase octane in both instances, so IMO, its up to you to pick your poison.
Adam
95strokerPSU
Member
I think one thing hasn't been answered yet, will 24#s support h/c/i and a 100 shot of nitrous. I'd like know as well. Nitrous will probably be the next thing after I do after I get a new steering rack.
H/C/I + nitrous you will want larger injectors. my GT40P/cobra intake combo is almost too much for 24lb injectors95strokerPSU said:
30's or larger
Black95GTS said:
nitrous is more compatible with higher c/r's cuz its cooler. heat=increased chance of pre-ignition and detonation. heat is a by-product of higher boost levels. this is why ign timing has to be lower and either an intercooler/methanol is prefered.
like joe said--cam selection is very critical. static compression is a very small part of what type of octane your engine needs. a rep from crane cams said he could grind a cam on an 8:1 motor that would need 93 octane to run right.
Yobi1Kanobi
Member
- Apr 9, 2003
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24 should be fine with NOS. Depending on the kit especially on a wet kit being that NOS and Fuel is on two solenoids. With a Dry kit it will be fine since the fuel pressure will spike to about 80-90- psi during the injection but while on motor you will run perfect. I ran 30#ers with HCI but it ran pretty rich NA on a 150 shot it ran good then again my combo is different than yours the best thing to do is slap those 24s on there and dyno tune it.
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