SN95 350hp Possible With Bolt Ons?

leesoc686 said:

wondering if 350hp to the rear wheels is actually possible with just bolt on mods? i want to get my sn95 on the dyno here soon but live an hour an a half from phoenix. this is what i have installed so far on my manual 95 gt 156k miles.
-bbk CAI
-bbk LT headers
-bbk 70mm TB
-bbk off road xpipe
-bama 4bank eliminator chip
- flowmaster cats
i plan on installing a cam and gt40x heads here soon as well. any ideas of what im pushing for rwhp as of now with my current mods?

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madmike1157 said:

I'd say that it's entirely possible..........

Right after Hell freezes over.

The engine was rated at 215 flywheel HP brand new. Eliminate 20% of that for drivetrain loss to get a RWHP figure....

Lets just say you had 175 at the wheels.

Brand new.

But your car aint brand new, it has 156 k on it. And it's a GT. It has seen some abuse. But the engines weather well, and they stay relatively well sealed up during their lifespan,.so we'll only subtract 5% of that for age.....

You have a whopping 168 RWHP.

Now,.....what do we add from all of your mods?.......
25 HP.
Your car currently makes a brutal 193 WHP.

Your plans to install X heads, and a cam will add another 50 to that number (maybe),..so I'm thinking that you may see 235-245 RWHP after all of that.

Where you're gonna get that extra 100 HP to satisfy your HP target, is gonna have to come from a whole bunch of extra cubic inches, a blue bottle, or a compressor.

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Chuckman said:

I think this post right here proves that you need to stay out of threads like this. The guy comes in here and asks a reasonable question that has a realistic answer, and as usual in a power/go fast thread, you go on a rant that does nothing but to demoralize the op and essentially call him an idiot for wanting to upgrade his car. If you look around, there's a lot of us who have gotten close to or surpassed the goal the op asked about, it's actually fairly common and not that complex just takes proper parts selection and being able to ask questions (remember the only stupid question is the one not asked) without fear of being bashed.

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leesoc686 said:

wondering if 350hp to the rear wheels is actually possible with just bolt on mods? i want to get my sn95 on the dyno here soon but live an hour an a half from phoenix. this is what i have installed so far on my manual 95 gt 156k miles.
-bbk CAI
-bbk LT headers
-bbk 70mm TB
-bbk off road xpipe
-bama 4bank eliminator chip
- flowmaster cats
i plan on installing a cam and gt40x heads here soon as well. any ideas of what im pushing for rwhp as of now with my current mods?

Click to expand...

Chuckman said:

I think this post right here proves that you need to stay out of threads like this. The guy comes in here and asks a reasonable question that has a realistic answer, and as usual in a power/go fast thread, you go on a rant that does nothing but to demoralize the op and essentially call him an idiot for wanting to upgrade his car. If you look around, there's a lot of us who have gotten close to or surpassed the goal the op asked about, it's actually fairly common and not that complex just takes proper parts selection and being able to ask questions (remember the only stupid question is the one not asked) without fear of being bashed.

Click to expand...

madmike1157 said:

I'd say that it's entirely possible..........

Right after Hell freezes over.

The engine was rated at 215 flywheel HP brand new. Eliminate 20% of that for drivetrain loss to get a RWHP figure....

Lets just say you had 175 at the wheels.

Brand new.

But your car aint brand new, it has 156 k on it. And it's a GT. It has seen some abuse. But the engines weather well, and they stay relatively well sealed up during their lifespan,.so we'll only subtract 5% of that for age.....

You have a whopping 168 RWHP.

Now,.....what do we add from all of your mods?.......
25 HP.
Your car currently makes a brutal 193 WHP.

Your plans to install X heads, and a cam will add another 50 to that number (maybe),..so I'm thinking that you may see 235-245 RWHP after all of that.

Where you're gonna get that extra 100 HP to satisfy your HP target, is gonna have to come from a whole bunch of extra cubic inches, a blue bottle, or a compressor.

Click to expand...

jrichker said:

Do the math...

The common figure for power loss through the drivetrain is 15%-20%. So subtract that .15 from 1.00 and you get .85
To get 350 rear wheel HP, take that 350 and divide it by . 85 = 411.76HP at the flywheel.

Let's recalculate using a 20% loss...
So subtract that .20 from 1.00 and you get .80
To get 350 rear wheel HP, take that 350 and divide it by . 80 = 437.5 HP at the flywheel.


The odds of getting that kind of HP out of a stock block, pushrod engine without pressurized induction or NO2 are very small. And if by some miraculous combination of parts and tuning you did do that, it would be unpleasant to daily drive on the street. The engine would have to be high RPM rev monster with very little torque in the 1200-3000 RPM range where most street driving is done.

In short, if you want that kind of performance by just turning wrenches, buy a Coyote crate engine and control pack and a few add ons...

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A5literMan said:

While I'm all for a coyote motor...this is antiquated advise. Love your tech advise J but this just isn't entirely true. With the proper parts you can come darn close to this mystical "350rwhp". Heck Nic built his as a daily driver(around 340rwhp) and has a very very mild cam. To get to this power level the op is going to need some very good flowing heads. NOTHING gt40! They won't come close(maybe 300whp). Going to take at least a 190cc head(some have come close with AFR 165's also). There are a lot of 400 flywheel horsepower 302's these days. And it doesn't take some crazy aggressive cam profile to get there. For example the custom I had done was 223/227* dur at .050 with .525 lift. Not much different than the almighty B cam and surely is driveable and makes way more power down low than a stock motor. Now it is going to be "lumpy" and isn't docile like a stock cam obviously.

Is such a motor going to be a "torque monster"? Not really, but it will still make more power in the off idle-2500rpm range than a stock motor. It also will start adding significantly from that rpm range up to redline. With the proper parts the ENTIRE power band will be increased. Takes good parts DESIGNED for that operating range. Which means BIG heads,higher flowing intake,tb,MAF,fuel system,proper cam timing,exhaust system,and some ECU tuning. The days of some giant cam that limits vacuum for brakes, and is silly soft down low, are over. Heck look at the dreaded LS pushrod motors. Big heads and mild cams=400+hp and with small tweaks they make well into the 500hp range N/A. Our little pushrod 302's are more than capable of 400 hp. Just takes good parts that cost significant money. The op isn't going to get there with his planned parts but if that truly is the goal(350whp) it can be done. For all the older members, anybody remember Nic's build? He's been daily driving it for years(330-340whp w/shorty headers and a cam with 218* duration).

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FoxMustangLvr said:

Agreed. People should just stay out of these threads if they can't show some respect and come off as a jerk like @madmike1157

I think these threads are fun when we get to spend other people's money. Also to note that a few people have had impressive results with a GT-40 combo pulling in about 260-275 rwhp. Not sure what the cost difference would've been if they had just gone with your typical aluminum TFS or AFR head but it's not a lost cause to go with GT40's if you're not too power hungry.

I think a good bang for buck combo is a worked over set of gt-40 heads, t-moss explorer intake, custom cam, Vortech V3. The stock block would be safe and this combo should shred lots newer cars with the 375-400rwhp you have (give or take).

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jrichker said:

The 411-437 flywheel HP figures means that you may have a stock block but that is where the similarity ends.

So far out of all the posts I have seek only clean LX has come anywhere near these numbers.
See his story at http://www.stangnet.com/mustang-forums/threads/na-306-e7te-heads-336hp-313tq.874305/ He spent a pile of money to do it, but his is the closest to the OP’s desire for 350 rear wheel HP out of 302 cu in.

What has to be done to make those kinds of numbers?
1.) The engine may have a stroker kit that expands the 302 cu in to 327-347 range.

2.) An engine is basically an air pump. That means you have to suck up a lot more air and mix it with the properly metered amount of fuel to make that kind of power. In order to make that happen you have in increase the airflow into the cylinders. There are 3 ways to make that happen

A.) Increase the port volume, and flow in CFM.
This does work but the low RPM intake air velocity makes for a sluggish car at low RPM. You have to wind the engine up past 3000 RPM to get the performance level that you want. Driving in stop and go city traffic is a big headache When you do find an opening in traffic, you have to find some method to get the revs up into the range where the engine pulls hard and doesn't bog. That means you need a loose torque converter or you slip the clutch.

B.) Valve opening and closing rates, cam timing and overlap.
The valve train in a pushrod engine and especially one with stud or pedestal mounted rocker arms does not take well to suddenly opening a valve and closing it just as quickly. Very high ramp rates are a characteristic of a small engine that has any kind of decent low RPM performance and this requires a very stiff and sturdy valve train. Wind the engine up above 6500 RPM and the inertia of the moving parts plays havoc with the valve timing unless you have some super duty valve springs and maybe solid lifters. Shaft mounted rocker arms can fix some of this but they won’t cure heavy valves and mismatched valve springs. Cam timing is fixed in 302 engines, whatever you did with the advance/retard trick sprocket or offset is what you are stuck with. The newer engines have a computer controlled cam advance/retard that gives them some advantage that Fox 5.0 pushrod engines don’t have.
The same is true of valve overlap; the exhaust valve and intake valve are open at the same time. This is to help scavenge the engine exhaust and make up for the inertia of the slow moving air column that will fill the cylinder. Normally, when the intake valve opens, it takes a finite amount of time to develop enough air flow velocity to move the air quickly enough to fill the cylinder 100%. The trouble is that this only works well at a cruse RPM range or higher. That’s why some cams cause the engine idle to lope or surge. The incomplete scavenging of the exhaust gases causes dilution of the incoming air/fuel charge. That lope or surge hurts low RPM/low speed performance, making for uncomfortable street driving unless the car has 4.xx or numerically higher rear axle gears to keep the RPMs up. It is a must to keep the engine turning enough RPMs to smooth out the pulsing nature of increased valve overlap.

C.) Careful tuning of the lengths of the exhaust and intake manifold runners can make the valve overlap work to the advantage of higher HP output. If the length of the intake runner is tuned correctly, then at a specific engine RPM range with the valve opens the air charge in the intake has hit the manifold plenum and reverberated back to the intake valve. That intake valve opens and finds a column of air pressing against it, waiting to get in the cylinder. The same effect works in reverse on the exhaust. The tuning works to insure that there is lower pressure at the exterior of exhaust port than the incoming intake air charge. Thus it sucks out the exhaust gases and sucks in the intake air/fuel charge.
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3.) Run the engine at very high RPM.
A small displacement engine like a 302 would need to wind up to the 7000 RPM range. That means a stiffer block and everything balanced to perfection. Both of those concepts are expensive to implement and require some very high quality machine work and assembly. As RPM increases, the forces trying to tear everything apart increase at a rate faster than the increase in RPM. Remember that this is supposed to be a stock block and probably a stock crank and rods.

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