Easy way to add HP?

[Selo]

Selo here, 302 with GT40 heads, E303 Cam, Edelbrock manifold, EZ Fast EFI, 3.31.gears, Trac Loc.....runs strong but I wouldn't mind a little more urgency. Living at 5000 ft altitude saps about 15% supposedly. Ideas for ways to add some grunt? Would like to avoid forced induction.
Thanks,
Mike

[Jerry Clayton]

NOS
Cubic inches
Super charger
Turbo chargers
Move to lower altitute

[Blas]

If you have a 3000 lb car with 500 HP each HP is moving 6 LBS. so if the driver goes on a diet and looses 25 pounds, each HP is only moving 5.95 pounds. Just like free HP.

[Jerry Clayton]

yeh, but he's only got about 200hp-----------

[Selo]

Originally Posted by Jerry Clayton

yeh, but he's only got about 200hp-----------

I was told it's more than that, and it feels like more than that. Supposedly should still be making in the high twos, even with 15% loss at this point.

[MKS427]

Check your headers, if they are small port and your heads are large port, there is good potential there.
Without forced induction: 10:1 pistons, bigger heads and bigger cam.
However, now you are getting into serious $ with possibly 10-15% increase in power. Depending on available funding a stroker motor (408-445" 7-12K) could be your best bang for the buck.
Look at craftperformanceengines.com for prices. You'll want to budget an additional 3K for shipping, headers, pulleys, low profile oil pan etc.
Hope you find what works for you

[Jerry Clayton]

OR----------put in an Chev supercharged, FI, LT4 from new Corvettes????light weight, etc,etc

[eschaider]

Originally Posted by Jerry Clayton

NOS
Cubic inches
Super charger
Turbo chargers
Move to lower altitute

Jeryy hit the nail square on the head. Those are the real power enhancers available to you that will make a seat of the pants difference. All that is left is for you to pick your poison.

A blown and injected 300 inch engine with a screw blower will easily produce a reliable 600 HP RWHP solution with a table flat torque curve that will give you an instantaneous vehicle response to any change in throttle position. Belt driven screw blowers are nothing short of stunning!


Ed

[t walgamuth]

drop your diff to a 373 or 410. The difference will feel dramatic and the only loss is top end which may be limited by rpm. Cheapest fix available except for Nitrous which I would not use.

[Selo]

Maybe a supercharger is the way to go. What is the SC of choice for these units? I really don't want sick power, maybe 400 hp or so.

[MKS427]

Look at a Paxton type centrfugal, which mounts on the front of the engine.
In all cases you will want to ensure your injectors, head gaskets, fasteners, cam, and compression ratio are compatible.

[eschaider]

Originally Posted by Selo

Maybe a supercharger is the way to go. What is the SC of choice for these units? I really don't want sick power, maybe 400 hp or so.

If you are looking to optimize top end power centrifugal compressors will be your best bet. If you go with a crank driven unit or exhaust driven unit (turbos) you will produce some impressive upper rpm power numbers.

If you are looking for more robust bottom end and midrange power with instant throttle response you want a screw blower like a KB or Whipple. Both will produce good top end power but not as much as the centrifugal style compressors.

None of the boosted conversions are inexpensive. Turbos tend to be near the top of the conversion cost charts because of the complexity and need to custom fit the supporting plumbing into a given car. Centri's and screws are less damaging to the wallet.

A centric like a Vortech or similar will typically come with a pretty well thought out kit that while not a bolt in, approximates one fairly well. The Screw blowers install effort will be a bit more than the centre's and well below the turbos.

The question you need to resolve is how much cost and effort do I want to sign up for.


Ed

[Selo]

Great info, thank you. My question is cost. A new motor is 6-10, right? But I could sell my current motor for 2-3. So what's a FI system cost? At some point it might be less complicated and more cost effective to put in a new motor.

[120mm]

In your situation I would drop a 347 stroker in it.

It is exactly the same, externally, as what you have in it, and making 400 hp is pretty easy.

You could also stroke the current engine, if the heads will take the additional air flow.

Is it tuned for your altitude, correctly?

[120mm]

Having said that, a 408W is a nice wee beastie to put in there, if you do not want to go FE.

[eschaider]

Originally Posted by Selo

Great info, thank you. My question is cost. A new motor is 6-10, right? But I could sell my current motor for 2-3. So what's a FI system cost? At some point it might be less complicated and more cost effective to put in a new motor.

This is another good alternative if you elect not to keep your current engine.

As a rule of thumb I want my Cobra driving experience to be a more responsive spirited sort of event than my daily driver so I look for things like throttle response and seat of the pants confirmations.

To get the necessary attitude adjustments when I drive, I found I needed somewhere north of about 400/450 hp. That number can and does move around (and usually moves higher) the longer you own the car.

Lets be conservative and say you loose 15% of your sea level power at altitude. If 400 is your power target then you need an engine that is rated for approximately 470 HP at sea level. If 450 is your target then you need an engine that is rated for ~530 HP (or so) at sea level.

Those are relatively easy to achieve goals.


Ed


p.s. I would be less focussed on the big block small block sort of criteria and pay the most attention to how much low speed torque my engine choice provides. 530 HP with 500 ft/lbs of torque at 3000 rpm is a very different driving experience than 530 HP with 390 ft/lbs of torque but at 7200 rpm — extreme examples but you get the gist.

[Selo]

Best place to buy a 347 Stroker with warranty?

[twobjshelbys]

Originally Posted by Selo

Maybe a supercharger is the way to go. What is the SC of choice for these units? I really don't want sick power, maybe 400 hp or so.

The Paxton is the most compatible with the Cobra setup. A small amount of boost (4-6psi) should be all you need. You'll definitely have to retune your EFI. And you may need to look at your fuel delivery (pump, lines) to be sure they can handle it.

I would caution you about adding too much horsepower. Cosby's 200 MPH routine was a documentary. Too much horsepower turns a Cobra into a death trap. You probably have a pretty nice streetable car. It wouldn't take too much more HP to turn the car into a "rear end breaks loose at the drop of a hat" - or any downshift or any upshift. My car had a Roush 427IR that engine dyno spec at 550hp, with about 500 at the wheels (I think their 550 was conservative). It took great care to not break the rear end loose.

[Selo]

Originally Posted by twobjshelbys

The Paxton is the most compatible with the Cobra setup. A small amount of boost (4-6psi) should be all you need. You'll definitely have to retune your EFI. And you may need to look at your fuel delivery (pump, lines) to be sure they can handle it.

I would caution you about adding too much horsepower. Cosby's 200 MPH routine was a documentary. Too much horsepower turns a Cobra into a death trap. You probably have a pretty nice streetable car. It wouldn't take too much more HP to turn the car into a "rear end breaks loose at the drop of a hat" - or any downshift or any upshift. My car had a Roush 427IR that engine dyno spec at 550hp, with about 500 at the wheels (I think their 550 was conservative). It took great care to not break the rear end loose.

That's what I'm trying to avoid.
Called Summit racing and they quoted about $4500 for the Vortech kit. That's too much. I think better to do a new motor than pay that much for a new FI system. U could spend 7 on an engine and sell mine for 2 and we're in the same ball park, with a less complicated set-up. Am I missing something?

[twobjshelbys]

The altitude is costing you maybe 50HP. I had dynos from sea level and in Loveland and that was all it cost. You can get a 50hp variation from run to run and from day to day depending on temp/humidity. Additionally, unless you spend a lot of time at the red line on a straight track, you won't notice 50hp. If all you are looking to do is make up for the altitude I think you're chasing something that won't be noticeable to you. If you start adding 100+hp, sure, it'll snap your neck harder, but it will also probably turn it into a monster, and it can become something you might not like to drive as much. Like I said, at 500rwhp, my car was too much. For that reason I still will, when I return to the Cobra market place, be more mindful of a small block car.

Be careful what you ask for, you might not like the answer since going back will be costly.