Supercharger vs. N/A build!

[twobjshelbys]

Sometimes the obvious things are overlooked so I'll ask...

Have you rejetted and adjusted your carb for high altitude operation?

I deliberately got fuel injection for mine (I lived in northern Boulder County, 5500', but had frequent operation above 10000' (especially when going over Trail Ridge, admittedly not a normal operating condition). A well designed DFI certainly helps these conditions, but a friend with the same engine - the Roush 427R (mine was IR for fuel injection) - in his GT40 ran great in the altitude band from about 5000-8000.

As an anecdote when I was "a kid" and we went from Iowa to Colorado, etc. my dad always had the carb reconfigured for high altitude. Another friend who ran carbs and took his car to sea level had two carbs and swapped them.

[twobjshelbys]

Originally Posted by Phill Pollard

I'm not sure where the 4.6 psi limit comes from unless you're talking about

I'm not saying you can't do more boost only that the guy I know runs very mild. Not a limit except for self imposed. I recall it being consistent with the setups of the day. Also this classic vehicle did not have an intercooler.

I'm also not sure what you can get out of the centrifugal types like Paxton and ProCharger.

[Bernica]

I know that for those of you that had Patrick at Pro Systems build your carb, you can call him anytime and tell him what elevation you plan on running at and even other weather conditions. He will look up your build and suggest what to do with jetting, etc.

[Cobrat24]

Originally Posted by twobjshelbys

Sometimes the obvious things are overlooked so I'll ask...

Have you rejetted and adjusted your carb for high altitude operation?

I deliberately got fuel injection for mine (I lived in northern Boulder County, 5500', but had frequent operation above 10000' (especially when going over Trail Ridge, admittedly not a normal operating condition). A well designed DFI certainly helps these conditions, but a friend with the same engine - the Roush 427R (mine was IR for fuel injection) - in his GT40 ran great in the altitude band from about 5000-8000.

As an anecdote when I was "a kid" and we went from Iowa to Colorado, etc. my dad always had the carb reconfigured for high altitude. Another friend who ran carbs and took his car to sea level had two carbs and swapped them.

Hey Tony,

To answer you on the elevation question, yes the car has been rejetted. The car just doesn't make enough power for my wants and needs. While we all were bringing up which direction to go on the motor, carb vs FI became a concern because of the elevation changes occasionally thru the year.

To your point I hate the idea of rejetting on the fly if I want to go to Tahoe or Auburn Ca. I think it's becoming painfully apparent that whether I go blower or cu build, FI will need to be considered.

[ct clint]

Ok seen all the post go efi add the charger and who cares if the motor don't survive it's not like it's rare. You can do bad things to stock 302 and they survive. Look for a used smashed mustang already done pull what u want sell rest off. If u get two years out of it then build motor you will have the knowledge of what u need at that point. I bought my v4 vortech for under 2grand used what's that like 12$us these days lol good parts are out there ask around lots of motors half done and guys run out of cash. Don't rush u are getting a lot of good info here for sure a lot of these guys have been down this road and it's nice to see such a good thread cheers

[Bernica]

Maybe just sell it all (maybe some other stuff) and start fresh with a supercharged Coyote engine and be done with it. Then you have the cubic inches and all you have been searching for.

[Cobrat24]

Ok fellas, I think I've decided to go to a big block, but where are you boys buying your blocks from? And I'm not taking about eBay either.

Spoke with my builder last night and let him know that's the direction I'm looking but he was telling me I'd be looking at 15k for example a complete Windsor build. This is blowing past my budget by 5k.

[patrickt]

Originally Posted by Cobrat24

Ok fellas, I think I've decided to go to a big block, but where are you boys buying your blocks from? And I'm not taking about eBay either.

Spoke with my builder last night and let him know that's the direction I'm looking but he was telling me I'd be looking at 15k for example a complete Windsor build. This is blowing past my budget by 5k.

If by "big block" you are thinking FE, then your $10k budget isn't going to get you there. 427 and 428 blocks are going to blow your budget to pieces -- a 390 less so. And a Windsor is not a big block. Whatever engine you choose, 289, 351, FE, or 385, I would let a trusted engine builder choose your block, not you.

[eschaider]

There is a reason that supercharged race cars run in different classes than n/a cars and it is not because the n/a cars make more power.

If you are funds limited then you should either set your sights lower (maybe accept lower power right now) and save until you can afford to build the bigger engine correctly.

Trying to make a beast of burden on a budget run like a purpose built high performance engine is a waste of your money and time. It will only increase the cost of what you want by the dollars you spend on the engine you didn't want.

Decide what you want, what it will cost and begin saving and buying parts as they present themselves to you. When you are done putting perfume on a pig it is still a pig. Budget, save, buy, build and then enjoy.


Ed

[Dwight]

Where are located?

[Cobrat24]

Originally Posted by Dwight

Where are located?

Reno, NV sir!

[Dwight]

I have eight or nine FE blocks. But I live in north Alabama shipping may be expensive

[Cobrat24]

[quote=eschaider;1376906]There is a reason that supercharged race cars run in different classes than n/a cars and it is not because the n/a cars make more power.

If you are funds limited then you should either set your sights lower (maybe accept lower power right now) and save until you can afford to build the bigger engine correctly.

Trying to make a beast of burden on a budget run like a purpose built high performance engine is a waste of your money and time. It will only increase the cost of what you want by the dollars you spend on the engine you didn't want.

Decide what you want, what it will cost and begin saving and buying parts as they present themselves to you. When you are done putting perfume on a pig it is still a pig. Budget, save, buy, build and then enjoy.


Ed[/QUOTE


Thanks Ed. I appreciate your advice man.

I plan on doing something one way or another, the cobra is too slow. So if it's slapping on heads , cam , intake and better exhaust for 450hp on the 302, although that won't be rear wheel it's better than what I have now by at least a 100hp.

[Cobrat24]

Originally Posted by Dwight

I have eight or nine FE blocks. But I live in north Alabama shipping may be expensive

Can you send some pics sir? And a zip code just incase I decide to research shipping.

Much appreciated you trying to help spend my money ... Lol

[patrickt]

Originally Posted by Cobrat24

Reno, NV sir!

There are more used auto parts and salvage yards in Nevada than anywhere else, except maybe Texas. Of course you know that all blocks that look the same are not the same. Some have those pesky little hairline cracks, core shift, and skinny little walls that won't let you bore them out without getting wet...

[Bernica]

Originally Posted by patrickt

If by "big block" you are thinking FE, then your $10k budget isn't going to get you there. 427 and 428 blocks are going to blow your budget to pieces -- a 390 less so. And a Windsor is not a big block. Whatever engine you choose, 289, 351, FE, or 385, I would let a trusted engine builder choose your block, not you.

Yup. As an example, a new bare Shelby FE aluminum block is about $7k from Shelby and a completely built FE from them starts at just under $30k and goes up from there.

Of course, you can start with a good used FE block, but take heed and do your homework on them before you lay down the $$. Many horror stories here and out there.

Before buying used, I would pay a quality builder to go through the block thoroughly and give you the final thumbs up or down.

[patrickt]

Originally Posted by Bernica

Of course, you can start with a good used FE block, but take heed and do your homework on them before you lay down the $$. Many horror stories here and out there.

But, mind you, if you do not suffer the fate of the horror stories, there is a school of thought that a "seasoned" iron block, with decades of heat cycles, and with nice thick walls, is superior in many regards. Not the least of which can be your DEQ inspector, if that matters, which it might not, but it might.... Personally, give me a beautifully seasoned, original iron block any day of the week.

[rodneym]

Originally Posted by patrickt

Personally, give me a beautifully seasoned, original iron block any day of the week.

Me, too. With one minor deviation...

Personally, give me a beautifully seasoned, original iron block any day of the week, so long as it goes in a beautifully seasoned, original Cobra.

[hinoonaz]

I just want to give you one more person to talk to. Robert at AIMS there in Reno. 775-359-8866. He rebuilt my 347. Unbelievable engine. He does a lot of work for my nephew at lake Tahoe and vice versa for the wood boat engines. Worth a call. No bias about all the other builders on this site. Holley 650 at 462 T and 470 hp. 9 1/2 :1 nice lopey cam and vic heads. The 408 if want over 500 IMO. Have fun.

[olddog]

Be warned that Ford started with Speed Density. It uses a MAP sensor in the manifold to estimate what the air flow into the engine is at a given throttle position. It does not work well with big cams, as the vacuum can be lower at idle than it is at off idle with such a cam. Second it does not automatically adjust for altitude changes. When you turn the key on the ECU saves the MAP sensor reading and assumes that is the atmospheric pressure. It does not update again until you turn the engine off and restart. So if you drive 4000 feet up a mountain, its no better than a carb, however turning the engine off/on is much easier than changing jets.

Then Ford went to Mass Flow to truly measure the mass of the air entering the engine. It handle big cams much better than speed density, and you can start at sea level and drive to 12000 feet with perfect AFR. Now there are issues with big cams, but that is another long story on what is needed to compensate.

Most after market system are speed density with an option to go to alpha N. Alpha N uses throttle position only and is more crude than speed density. These systems can be tuned to run well, but they will not automatically compensate for elevation change.

Someone mention Pro M. Pro M used to be MassFlow. MassFlow used a 1989-1993 Mustang A9L ECU. I have one on my Cobra. It is a decent system, but in my opinion some of the claims were BS. Before going to a quarter horse chip from Moats and software to tune it myself, I looked hard at the new Pro M. It looks like a great system to me, but I did not buy it. I would have had to replace too much and spend to much $$ to switch over to it. If I remember correctly the cost of a complete system (fuel pump to intake, inclusive - wire harness and distributor) is ~$3500 give or take. I would look hard at that.