Easy way to add HP?

[lnfletcher]

Originally Posted by Selo

Best place to buy a 347 Stroker with warranty?

https://craftperformanceengines.com/...budget-331-347

[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.

[Selo]

Is it difficult to find a Coyote from a totaled unit, and what do they run?

[spdbrake]

Originally Posted by Selo

Is it difficult to find a Coyote from a totaled unit, and what do they run?

The on-line junkyard database Car-Part.com--Used Auto Parts Market
5.0
Approx $3.5k - up for just the engine, $5-7k for the Engine/ECU&harness/ 6sp manual.
5.2 from a GT350 $10-17K

[Danr55]

Sounds like the first thing you need to do is find out exactly how many ponies you are riding. Hook it up to a dyno and measure it. Find out where you are, then you will be able to determine where you are going. THe operator will likely have some ideas on how to improve it, also. With electronic ingnition, may be a simple as a different chip.

[1795]

You may also want to consider the power range that you will be typically running in. A power band that is targeted towards a power band in the 4,500-7,000 rpm range can provide impressive numbers, but unless you plan on driving in 1st and 2nd in town and 3rd on the highway only, it is not very practical for the street if your complaint is not enough power driving between 45-70 mph.

Look for an engine or changes that will put the power where you need it.

[Jdata]

Comparing the days when the Super Snake was created to now are two different eras IMHO. There seems to be far more powered kits in the realm of the Super Snake nowadays than the total of them made.

I am pretty sure adding the C4 really screwed the F/R distribution. E.g. Moving weight to the front to an already biased one because of the dual Paxtons. Talk about a light rear. Tire technology was abysmal back then.

[jhv48]

I had an FFR with a 302 much like yours. BUT, I had 3.73 rear gears. Made my engine come alive. If you don’t want a power adder such as a turbo or supercharger, lower gears are your least expensive option.
Luckily, you’ve got FI so you don’t have to make jet adjustments for high or low altitudes.
If you do decide to swap out the engine, and keep the 3.31 rear gears, look for a torquer engine, not a revver. Lots of torque right off idle. The reason is that your rear end will work against you at that altitude and you’ll never get to use that overdrive 5th if you have a high strung engine.
I currently have a 560 lb/ft engine and a 3.46 rear end. Would love a 3.31 as it would make first gear much more useable.

[olddog]

The flatter the torque curve (the closer the torque is to a flat line) over say 2500 to 5500 rpm, the more predictable and therefore the easier the car is to handle. If all you're interested in is drag racing (idle or full throttle), this isn't important. If you are driving around twisty roads and are not a trained race driver, then the flat torque is very important. Possibly life saving important.

That said stay away from centrifugal blowers. They make almost no pressure at low rpm.

I think if I was in your shoes, I would sell the engine if you can get anywhere near what you said. Those heads make more power than the stock factory heads, but not much more. The E303 cam sounds good and that is about all it does. The only thing I would use out of that engine is the Block, and lifters.

Go 347 stroker. Spring for a boss block or aftermarket if you can afford it. Better oiling and stronger. For a couple hundred more you can go to a 4.125" bore and get some more CID and un-shroud the valves. Put good heads on it. The heads make the engine. Don't screw up a perfectly good engine with a junk intake. Match the cam up to everything else.

Talk with Brent Lykins or Craft Racing, whichever you are closer to.

[moore_rb]

Originally Posted by olddog

That said stay away from centrifugal blowers. They make almost no pressure at low rpm.

This is an accurate point when applied to the older style belt-driven hair dryers (which "feel" a lot like turbos as they spool up); but the latest crank drive blowers out there now are able to start adding boost as low as 1500RPM...

[olddog]

Originally Posted by moore_rb

This is an accurate point when applied to the older style belt-driven hair dryers (which "feel" a lot like turbos as they spool up); but the latest crank drive blowers out there now are able to start adding boost as low as 1500RPM...

They can angle the blades and make improvements, but a true centrifugal blower, the pressure output is proportional to the tip speed of the blades. The relationship is typically pretty close to: pressure equals tip speed squared. Since it is difficult to fit a 3 foot diameter blower in a car, they end up with a small diameter and a planetary gear set spinning the wheel up to 80,000 rpm to make pressure. At low rpm the boost is very low, with little increase in boost for a 1000 rpm motor increase. At high rpm, boost is high, and a large increase in boost for a 1000 rpm motor increase. Torque is proportional to boost, and boost increases with the rpm squared. This gives a very steep increase in torque over the rpm range, until the engine pumping efficiency starts dropping off rapidly. Once that point is reached, the centrifugal blower and engine combine to flatten the torque out for a while.

Multi stage compressors wheels exist in industry, but I have never seen them in an auto application. The pressure is still proportional to rpm, but not as steep. These need a good deal of application design and cannot handle a lot of variable changes, as they can get into vibration harmonics and destroy themselves. I don't see these going into auto applications, but I get surprised all the time. I just doubt that there is any centrifugal blower that doesn't have a steep rpm to pressure curve. Physics doesn't change much.

Now change to the roots bower, or better, a screw compressor and they are positive displacement blowers. You pretty much get the same boost pressure (thus torque) at all rpms.

So let's assume your engine NA has 300 ft-lb torque from 2500 - 4500 rpm and then it starts dropping off to say 250 ft-lb at 6000 rpm. With a centrifugal blower you may get 350 ft-lb at 2500 rpm at 2.5 psi boost. At 4500 rpm you are likely at 8.4 psi and 470 ft-lb. At 6000 rpm you are likely at 15 psi and 500 ft-lb. Some of that torque would be consumed by the blower belt, but that's more work than I wanted to put into this, so I am ignoring those losses.

In comparison if you used a positive displacement compressor at 15 psi boost (again ignore power robbed to drive the blower) you would double the torque everywhere. So cruising down the road and pulling up a mountain at 2500 rpm the positive displacement would would have about 600 ft-lb of torque available, where the centrifugal would only have 350 ft-lb available (only 50 more than the engine had normally aspirated). Sure drop two gears and rev it up to 6000 rpm, they both have the same torque, but every place below that, the positive displacement wins hands down.

I hate a different torque at every rpm. So you come out of the first turn at 2500 rpm smash it to the floor and get a modest 350 ft-lb of torque. Yea this is fun. The next corner you are at 4500 rpm and smash the throttle, expecting the same fun, only the engine pumps out 470 ft-lb of torque. The tires break loose on a corner, in a 90 inch wheel base car, and you are dead.

With the centrifugal smash it in first gear, and your tires will hold to the ground until the rpms come up. If you do not back off the throttle before the tires break loose they will rapidly go up in smoke. To keep the tires from breaking loose, you have to continually back off the throttle, as the rpms increase to keep the tires hooked. Same thing in every gear. Not for me.

[moore_rb]

Originally Posted by olddog

They can angle the blades and make improvements, but a true centrifugal blower, the pressure output is proportional to the tip speed of the blades. The relationship is typically pretty close to: pressure equals tip speed squared. Since it is difficult to fit a 3 foot diameter blower in a car, they end up with a small diameter and a planetary gear set spinning the wheel up to 80,000 rpm to make pressure. At low rpm the boost is very low, with little increase in boost for a 1000 rpm motor increase. At high rpm, boost is high, and a large increase in boost for a 1000 rpm motor increase. Torque is proportional to boost, and boost increases with the rpm squared. This gives a very steep increase in torque over the rpm range, until the engine pumping efficiency starts dropping off rapidly. Once that point is reached, the centrifugal blower and engine combine to flatten the torque out for a while.

Multi stage compressors wheels exist in industry, but I have never seen them in an auto application. The pressure is still proportional to rpm, but not as steep. These need a good deal of application design and cannot handle a lot of variable changes, as they can get into vibration harmonics and destroy themselves. I don't see these going into auto applications, but I get surprised all the time. I just doubt that there is any centrifugal blower that doesn't have a steep rpm to pressure curve. Physics doesn't change much.

Now change to the roots bower, or better, a screw compressor and they are positive displacement blowers. You pretty much get the same boost pressure (thus torque) at all rpms.

So let's assume your engine NA has 300 ft-lb torque from 2500 - 4500 rpm and then it starts dropping off to say 250 ft-lb at 6000 rpm. With a centrifugal blower you may get 350 ft-lb at 2500 rpm at 2.5 psi boost. At 4500 rpm you are likely at 8.4 psi and 470 ft-lb. At 6000 rpm you are likely at 15 psi and 500 ft-lb. Some of that torque would be consumed by the blower belt, but that's more work than I wanted to put into this, so I am ignoring those losses.

In comparison if you used a positive displacement compressor at 15 psi boost (again ignore power robbed to drive the blower) you would double the torque everywhere. So cruising down the road and pulling up a mountain at 2500 rpm the positive displacement would would have about 600 ft-lb of torque available, where the centrifugal would only have 350 ft-lb available (only 50 more than the engine had normally aspirated). Sure drop two gears and rev it up to 6000 rpm, they both have the same torque, but every place below that, the positive displacement wins hands down.

I hate a different torque at every rpm. So you come out of the first turn at 2500 rpm smash it to the floor and get a modest 350 ft-lb of torque. Yea this is fun. The next corner you are at 4500 rpm and smash the throttle, expecting the same fun, only the engine pumps out 470 ft-lb of torque. The tires break loose on a corner, in a 90 inch wheel base car, and you are dead.

With the centrifugal smash it in first gear, and your tires will hold to the ground until the rpms come up. If you do not back off the throttle before the tires break loose they will rapidly go up in smoke. To keep the tires from breaking loose, you have to continually back off the throttle, as the rpms increase to keep the tires hooked. Same thing in every gear. Not for me.

We're still not talking about the same thing... You are still hammering on fixed ratio, belt driven superchargers... and I don't disagree with anything you wrote (yes, I read your WHOLE post )

However, what if the ratio of engine RPM to compressor RPM wasn't fixed? what if you could vary the impeller speed and set the boost level wherever you wanted it, at almost any RPM? What if your blower could be PROGRAMMED to work with a MAP sensor, and a variable speed transmission, to deliver more boost at lower engine RPMs, and less boost at higher RPMs in order to provide a nice, broad, flat torque curve...?

Yes, you sure can....

https://www.procharger.com/procharger-i1

[olddog]

Originally Posted by moore_rb

We're still not talking about the same thing... You are still hammering on fixed ratio, belt driven superchargers... and I don't disagree with anything you wrote (yes, I read your WHOLE post )

However, what if the ratio of engine RPM to compressor RPM wasn't fixed? what if you could vary the impeller speed and set the boost level wherever you wanted it, at almost any RPM? What if your blower could be PROGRAMMED to work with a MAP sensor, and a variable speed transmission, to deliver more boost at lower engine RPMs, and less boost at higher RPMs in order to provide a nice, broad, flat torque curve...?

Yes, you sure can....

https://www.procharger.com/procharger-i1

Wow I am behind the times. I read where one of the German car companies were experimenting with a continuous variable drive design on a positive displacement blower. If memory serves they were shooting for no throttle plate. Quite a few years back.

Ok now that I am up to date, yes that would work as you described.

Thanks for the link and explanation.

[MKS427]

Originally Posted by moore_rb

We're still not talking about the same thing... You are still hammering on fixed ratio, belt driven superchargers... and I don't disagree with anything you wrote (yes, I read your WHOLE post )

However, what if the ratio of engine RPM to compressor RPM wasn't fixed? what if you could vary the impeller speed and set the boost level wherever you wanted it, at almost any RPM? What if your blower could be PROGRAMMED to work with a MAP sensor, and a variable speed transmission, to deliver more boost at lower engine RPMs, and less boost at higher RPMs in order to provide a nice, broad, flat torque curve...?

Yes, you sure can....

https://www.procharger.com/procharger-i1

WOW, Impressive numbers on the Coyote! That could easily be 580 TQ at the crank.
I originally suggested a centrifugal, because I am not aware of a screw type for a 302 Windsor, that won’t pop up through the hood (bonnet).

[saki302]

My old car had 350ish rwhp, the SPF came with a dyno chart showing 472 at the rear (roush 427r).

On 10 year old rubber, it's unusable at anything over 1/2 throttle in the first 3 gears. I'm looking forward to stickier rubber on this one!

With these light cars I think a centrifugal blower like a Paxton will feel better. A positive displacement blower works great on heavier vehicles like my truck, but it doesn't take much to break the wheels loose on these light cars.

That said if you're going to get around 350 ish ft/lbs torque at the rear wheels, that's probably just right.

-Dave

[moore_rb]

Originally Posted by saki302

With these light cars I think a centrifugal blower like a Paxton will feel better. A positive displacement blower works great on heavier vehicles

Listen to this guy ^

There is only one way to make power, and that is to combine more cylinder pressure (not compression ratio, don't get these terms confused), with more/better exhaust scavenging, and to multiply these factors by adding either cubic inch displacement, adding raw oxygen (nitrous) or positive displacement (forced induction).


If your 302 is strong in all 8 holes, and doesn't make any blowby or leakdown, then at 5000 foot elevation, the best way to add cylinder pressure (without replacing the engine) is going to be with either turbocharging, supercharging, or nitrous. A direct drive centrifigal blower is the best mechanical method (meaning most efficient for the $) for acheiveing this goal on a small cubic inch engine, IMHO

I also like jhv48's point about the gears- lower rear gear can mean faster RPM ramp rate- very beneficial at higher altitudes.

[Selo]

Excellent. Thanks for the responses. Think Paxton SC.
But the real answer is No Easy way, as in not an inexpensive tune or bolt on. I need to make sure this is a darn good keeper before I put this kind of $ into it.

[Racer_X]

Originally Posted by 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

Dump that E cam. those are designed for heavier cars and IMO suck for performance. Might try a custom cam from Bullet.

Also, rear end gearing has been mentioned. You'll get that seat of the pants feel of acceleration but lose some top end speed. With a small block motor, doesn't make much difference as they can wind pretty high RPM's.

[Selo]

3.55? 3.73?
How do you go about choosing a new cam, how expensive to replace (sounds labor intensive) and as long as we're going to be in there, what else to do?

[eschaider]

Originally Posted by Selo

3.55? 3.73?
How do you go about choosing a new cam, how expensive to replace (sounds labor intensive) and as long as we're going to be in there, what else to do?

**** Note: Vigilink is adding links that I did not put into this post. If the link is not Bold Face, Italic and Blue it is an unrequested Vigilink link that should be ignored. ****

This is not meant to be deprecating Mike, but it sounds like you are in the deep end of the swimming pool and you don't know how to swim.

I think you might want to step back for a moment and do a little preliminary work. The cost to supercharge, done correctly with proper plumbing, headers and management hardware (if a turbo), intake manifold, intercooler and proper compressor is basically a $10K proposition for a screw blower and 2x that number for a turbo build — before you get to engine internals.

Your questions about n/a engine mods betrays a lack of experience in that area also — again not trying to woof on you. These engine modification or replacement adventures get expensive fast and even more expensive if you have to repeat the experience because of poor choices having been made.

While mechanical experience with engine building can be a good thing if you own one of these cars it tends to fall into two (successful) camps. One is just the installation and ongoing maintenance of the engine car combination and the other is the recipe for making reliable, usable well mannered horsepower with the engine platform you decide to use. The skills sets sound similar perhaps even the same at first glance. While complementary, they are very different.

If you do not have a pressing reason to immediately change your cars engine, I would like to suggest that discretion is the better part of valor here. Get some books and read up on what it takes to build a good version of one of these cars. Try to stay away from the all too common versions that describe the problem from multiple perspectives and never offer an explanation or solution.

There are two excellent books I would point you at. One is, Internal Combustion Engine Fundamentals. The title makes the book sound like an entry level primer that is not worth the effort. It is written by John Heywood. John is a Professor of Mechanical Engineering and Director, of The Sloan Automotive Laboratory at the Massachusetts Institute of Technology — the book is not an entry level primer. It is course material used in graduate and undergraduate engine design courses at MIT. The book is also not inexpensive it is between $30 and $50 on Amazon to rent and anywhere between $100 and ~$300 to buy used. The most recent edition can be purchased for $100 and change directly from the publisher on Amazon. Not cheap but well worth the price.

Heywood's book will be more than you need for the adventure you are about to embark on but it will go to the engineering design principles behind every decision that is necessary to creating the engine you are looking for.

The second book I would point you at is Physics For Gearheads by Randy Beikmann Ph D. It is a bit less expensive at approximately $50+ per copy. Before you think this is one of those upper atmosphere exercises for some type of automotive dilettante, I would ask you to reserve your opinion for a bit. The book is an understandable teaching tour-de-force on vehicle dynamics, energy and power.

In his opening comments on page 1, the author offers the following thoughts, "I figured the ideal Physics book would combine the gearheads knowledge of cars with the physical explanations of how they work. Familiar car examples could make the physics practically obvious and the Physics could explain why the designs end up the way they do ..." As he closes his commentary he says, "... this book is for those same people who kept asking why. And who still want to know more today."

The book is excellent and provides it's explanations in a clear, concise manner with simple four function mathematics using only multiplication, division, addition and subtraction. If you want to get into the higher math proofs, there are also more sophisticated explanations provided that will provide you all the insight you may want.

If the math and learning stuff is a bridge too far, there is still a working solution available to you. You have two excellent engine building choices available to you on the Club Cobra site.. One is Craft Performance Engines and the other is Lykins Motorsports. These guys know our cars and can quickly set you up with the solution you are currently trying to noodle out.

BTW irrespective of which of the three paths you choose to take, if you do the job correctly, you will be in the tank for decidedly more than $10K by the time you get everything done and that is a conservative number. If you take a learn as you go approach you are probably well over $20K and run the risk of becoming one of those oh so many advertisers you can find that is selling a car nearly complete but needs ... fill in the blanks.

Pick your poison.


Ed