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What's the limit?

Mr. Unknown

Member
Oct 26, 2005
24
0
How much can it handle?

I've heard 580-600 rwhp is safe but it's on borrow time.

I've also heard it's all in the tune.

I mean, forged internals, iron block. I'm not a engine builder but that sounds like the basics for something with serious power. Don't get me wrong, 600 rwhp is a lot.

It seems like a lot of goes blow there motor due to messing up the pistons. They seem to be the weak point.

I've also heard about twising a rod.

So my thought is. If heat is what kills the pistons due to the blower and high hp, would Nitrous cool it down and help?


I know I posted a lot of things that I've heard so I'm going to ask that only people that have done their homework come in with a reply. I don't want to hear my shit like O I read on this on svtp or that on svtp. I'm just tired of people chiming in with their .02 when the only experince they have with the topic is what they read online. :rantoff:
 

Big Cam Z28

banned from CorvetteForum
Jul 23, 2006
2,194
0
CobraChris08 said:
How much can it handle?

I've heard 580-600 rwhp is safe but it's on borrow time.

I've also heard it's all in the tune.

I mean, forged internals, iron block. I'm not a engine builder but that sounds like the basics for something with serious power. Don't get me wrong, 600 rwhp is a lot.

It seems like a lot of goes blow there motor due to messing up the pistons. They seem to be the weak point.

I've also heard about twising a rod.

So my thought is. If heat is what kills the pistons due to the blower and high hp, would Nitrous cool it down and help?


I know I posted a lot of things that I've heard so I'm going to ask that only people that have done their homework come in with a reply. I don't want to hear my shit like O I read on this on svtp or that on svtp. I'm just tired of people chiming in with their .02 when the only experince they have with the topic is what they read online. :rantoff:

find out what grade of metal it is, and i can help you out
 

Flyn

Go ahead. I'll catch up.
Moderator
TCG Premium
Mar 1, 2004
68,052
27,984
Selling homes on the Gulf Coast of Florida
There are some 700+ hp Cobras still on stock internals. As long as you keep the tune safe, watch your heat build up and don't do stupid things like long full throttle runs to the motor it should be OK for a while.

Plenty of Cobras live in the 600+ horsepower area.

Nitrous will cool the air intake charge which actually gives you more power using it. A 50 shot will probably give you more than 50 hp. Nitrous adds power which adds stress to the motor. With Nitrous you must make sure your tune is correct to avoid a lean situation which will blow the motor up quickly.

What you need to make a high hp Cobra more likely to live is:

A good tune.

Supporting mods so your fuel doesn't run out.

Cooling mods [all of them, not just ours. Radiators, heat exchangers, reservoirs, water pumps, oil coolers, etc.] Heat is the enemy. Keep it in check and your motor will be thankful.

Brains. Don't put the motor under intense periods of stress. Long full throttle runs, back to back dragstrip runs, high rpm driving, etc. are rough on the motor, build heat and can lead to the "BANG" you want to avoid.
 

rdsnake

formerly RD SNAKE
Mar 5, 2006
5,733
401
Flyn high again said:
There are some 700+ hp Cobras still on stock internals. As long as you keep the tune safe, watch your heat build up and don't do stupid things like long full throttle runs to the motor it should be OK for a while.

Plenty of Cobras live in the 600+ horsepower area.

Nitrous will cool the air intake charge which actually gives you more power using it. A 50 shot will probably give you more than 50 hp. Nitrous adds power which adds stress to the motor. With Nitrous you must make sure your tune is correct to avoid a lean situation which will blow the motor up quickly.

What you need to make a high hp Cobra more likely to live is:

A good tune.

Supporting mods so your fuel doesn't run out.

Cooling mods [all of them, not just ours. Radiators, heat exchangers, reservoirs, water pumps, oil coolers, etc.] Heat is the enemy. Keep it in check and your motor will be thankful.

Brains. Don't put the motor under intense periods of stress. Long full throttle runs, back to back dragstrip runs, high rpm driving, etc. are rough on the motor, build heat and can lead to the "BANG" you want to avoid.

I agree with everything Cliff is saying.

Chris, I wouldn't run more than 19 lbs of boost on 93 octane! All of the cooling mods are a must. I'm running a LFP radiator, Evans water pump, LDC cooling mod, LFP ice box, Fluidyne h/e. Brains is a must, when their is a problem, thats it theirs a problem no more beating on the car until it is fix.

Also, you have to be on top of what's going on under the hood. Everything must be right, plugs, gas EVERYTHING. You can't just mod the piss out of the cars then just drive them. My hood is open on my car more then I drive the car. I'm usually on top of everything that is happeneing.

Good gas is where it's at...Look at Boost 12, he's turning bad ass numbers on his stock shortblock. I'm sure he is using C16....

If you wanna beat on the car hard with 93 I would stay somewhere around 17 lbs of boost on a nice tune...

Kevin
 

ShelbyGuy

Turgid Member
Mar 26, 2004
5,230
0
like anything else, the more you ask it to do, the less often it will be able to do it.

nitrous caries an extra oxygen molecule for the air:fuel emulsion to bind to, so it increases cylinder pressure, and thus heat.

the closer you get to the ragged edge, the smaller your margin of error becomes.
 

Mr. Unknown

Member
Oct 26, 2005
24
0
Flyn high again said:
There are some 700+ hp Cobras still on stock internals. As long as you keep the tune safe, watch your heat build up and don't do stupid things like long full throttle runs to the motor it should be OK for a while.

Plenty of Cobras live in the 600+ horsepower area.

Nitrous will cool the air intake charge which actually gives you more power using it. A 50 shot will probably give you more than 50 hp. Nitrous adds power which adds stress to the motor. With Nitrous you must make sure your tune is correct to avoid a lean situation which will blow the motor up quickly.

What you need to make a high hp Cobra more likely to live is:

A good tune.

Supporting mods so your fuel doesn't run out.

Cooling mods [all of them, not just ours. Radiators, heat exchangers, reservoirs, water pumps, oil coolers, etc.] Heat is the enemy. Keep it in check and your motor will be thankful.

Brains. Don't put the motor under intense periods of stress. Long full throttle runs, back to back dragstrip runs, high rpm driving, etc. are rough on the motor, build heat and can lead to the "BANG" you want to avoid.



What fuel mods support up to what about of hp?





RD SNAKE said:
I agree with everything Cliff is saying.

Chris, I wouldn't run more than 19 lbs of boost on 93 octane! All of the cooling mods are a must. I'm running a LFP radiator, Evans water pump, LDC cooling mod, LFP ice box, Fluidyne h/e. Brains is a must, when their is a problem, thats it theirs a problem no more beating on the car until it is fix.

Also, you have to be on top of what's going on under the hood. Everything must be right, plugs, gas EVERYTHING. You can't just mod the piss out of the cars then just drive them. My hood is open on my car more then I drive the car. I'm usually on top of everything that is happeneing.

Good gas is where it's at...Look at Boost 12, he's turning bad ass numbers on his stock shortblock. I'm sure he is using C16....

If you wanna beat on the car hard with 93 I would stay somewhere around 17 lbs of boost on a nice tune...

Kevin


I wouldn't really try to shoot for anything over 600 on 93.


ShelbyGuy said:
like anything else, the more you ask it to do, the less often it will be able to do it.

nitrous caries an extra oxygen molecule for the air:fuel emulsion to bind to, so it increases cylinder pressure, and thus heat.

the closer you get to the ragged edge, the smaller your margin of error becomes.


That doesn't sound too comforting. lol


Thanks guys for your input.
 

Flyn

Go ahead. I'll catch up.
Moderator
TCG Premium
Mar 1, 2004
68,052
27,984
Selling homes on the Gulf Coast of Florida
CobraChris08 said:
What fuel mods support up to what about of hp?

Each car is different. You have to get your duty cycle checked to see how close to maximum fuel delivery you are.

With my ported blower and 2.76 pulley, I use a 2400 MAF, Boost a Pump and 60 lb. injectors. I might be able to get by with stock injectors but I'd be close to the edge. I'd rather be safe than sorry. If you want 600+, you'd need a bigger MAF and possibly dual fuel pumps and other fuel line modifications [Top hat mods]. Do a search here and on mod fords for "top hat" to read up on that fuel mod. Lyle and Dan have done extensive mods to their cars in that area and I think they have some threads up about it.
 

gnxs

Electron Powered
Apr 26, 2004
8,930
256
Trying to run 600rwhp (~700 crank hp) on a 4.6L stock longblock with 93 octane is a recipe for disaster. You have almost no margin for error. You'll typically need to run 18+ psi and a fair amount of timing to achieve 600rwhp SAE.

The key to keeping these motors alive at that power level is a good tune and plenty of octane. There's no big mystery here. There are a decent amount of cars with both high-power and high-mileage on this site and none of the ones I know of rely on pure 93 octane.

My $0.02.
 

Flyn

Go ahead. I'll catch up.
Moderator
TCG Premium
Mar 1, 2004
68,052
27,984
Selling homes on the Gulf Coast of Florida
gnxs said:
Trying to run 600rwhp (~700 crank hp) on a stock longblock with 93 octane is a recipe for disaster. You have almost no margin for error. You'll typically need to run 18+ psi and a fair amount of timing to achieve 600rwhp SAE.

The key to keeping these motors alive at that power level is a good tune and plenty of octane. There's no big mystery here. There are a decent amount of cars with both high-power and high-mileage on this site and none of the ones I know of rely on pure 93 octane.

My $0.02.

Good point.
 

Since 1964

TCG Elite Member
May 26, 2004
6,191
0
gnxs said:
Trying to run 600rwhp (~700 crank hp) on a 4.6L stock longblock with 93 octane is a recipe for disaster. You have almost no margin for error. You'll typically need to run 18+ psi and a fair amount of timing to achieve 600rwhp SAE.

The key to keeping these motors alive at that power level is a good tune and plenty of octane. There's no big mystery here. There are a decent amount of cars with both high-power and high-mileage on this site and none of the ones I know of rely on pure 93 octane.

My $0.02.

One of the GODS has spoken.

For me, I'll take whatever RWHP I can get from Whipple and a SAFE 93 octane tune and then on race day I would use more boost and octane just to be able to kick the MOST ass I can. I can barely hook what I have now and I don't think I'll need 600RWHP out on the street. I mean if you can beat me with 550RWHP God bless ya, but the odds of that happening are so miniscule it's just NOT needed.
 

Flyn

Go ahead. I'll catch up.
Moderator
TCG Premium
Mar 1, 2004
68,052
27,984
Selling homes on the Gulf Coast of Florida
dun4791 said:
82% duty cycle at 720rwhp with dual Gt supercar pumps, dual 6 an outs, 8an to rail, no PPRV, dual stock FPDMs, NO BAP, stock rails. I believe the dual stock FPDMs are the way to go with the GT pumps if you compare the data from my car and Jasons.

That translates to 828 flywheel hp. Not bad, Lyle.
 

JA$ON

ching chong potato
Sep 7, 2004
17,332
2
dun4791 said:
82% duty cycle at 720rwhp with dual Gt supercar pumps, dual 6 an outs, 8an to rail, no PPRV, dual stock FPDMs, NO BAP, stock rails. I believe the dual stock FPDMs are the way to go with the GT pumps if you compare the data from my car and Jasons.

Do you think youd make even more power @ 25 or 27 PSI? Or is 23 the sweet spot? I meant to ask James and Ed how high some people have spun the 2.8H's and what power increases they have seen at high boost levels
 
firstsvt said:
Nice, so you guys did squeeze a few more HP out of your car. You were seeing 23 PSI too right?? I think thats what you told me. Man I need an electric H20 pump and some real exhaust. I know I asked already, but I forgot, how much are your heads worked?

Do you think youd make even more power @ 25 or 27 PSI? Or is 23 the sweet spot? I meant to ask James and Ed how high some people have spun the 2.8H's and what power increases they have seen at high boost levels


Yes after James went in and modified the spark tables we got 718 at 20 degrees timing with 103 octane. This was at 24 lbs. But it was only 24 for about 1000 rpm or so right at the hit, then it dropped to 23 and held real steady. 4 lb lower 3.4 upper. Fox Lake did the heads. Stainless valves, bronze guides, ported, Crower 3s with better springs.

As far as power, Im sure I would have made more if I wanted to run more octane, so I could do more timing. On my street tune at 17* with the 100 octane( I run no less than 100 all the time) at the same boost level I was at mid 680s rwhp. From seeing the #s Im guessing that similar gains could be made from upping the timing as well as upping the boost. It is about 10-15 rwhp for every pound of boost or degree of timing. So there is another 70 hp or so on the table for a 1/4 mile guy such as yourself.

I dont remember what headers you had if any, but dont do the bassanis, do long tubes. The bassani headers are a PITA. And yes for you, definately do the water pump.
 
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