Supercharger vs. N/A build!

[ct clint]

Your best bet is ride in a car with a charger they just keep pulling. I am stepin up to a v4 vortech and use pro m efi his suff realy works even can control the meth and nos. Had v2 but bad things happen when u abuse them lol. I would go charger and efi it realy works.

[mikeinatlanta]

In GA I'd NA, but at 5,500' with the best local roads even higher I'd be all over the blower.

[Cobrat24]

Originally Posted by mikeinatlanta

In GA I'd NA, but at 5,500' with the best local roads even higher I'd be all over the blower.

I initially priced out doing heads, intake, big cam and carb; that was close to 9k with install and tuning. But it sounds like I'll be changing jets constantly if I drive it as I described. I'm wondering where I'd be with the blower and possibly FI.

[olddog]

I had a thought. If you sold your engine and add that to your budget of 10K, that should give you 12-14K, depending on what you can get. That should buy a top notch Windsor stroker.

If you drive over a wide elevation change, I think you should think hard on EFI. If you go with boost and have wide elevation changes, I think EFI is a must. Otherwise it is a lot of cost for little gain.

[Cobrat24]

Originally Posted by olddog

I had a thought. If you sold your engine and add that to your budget of 10K, that should give you 12-14K, depending on what you can get. That should buy a top notch Windsor stroker.

If you drive over a wide elevation change, I think you should think hard on EFI. If you go with boost and have wide elevation changes, I think EFI is a must. Otherwise it is a lot of cost for little gain.

Didn't even think about that part in regards to selling the engine. Hmmmm great idea to look into. Yea the more we all post on this thread, the more I look at it and realize how much elevation change I have in my area. You drive another 40 minutes and you end up in Auburn Ca, and that elevation is 2000. So that's just another example of the elevation difference.

So to sum it up elevation varies from 2000-7000 depending on where I drive. FI is a whole another animal to the equation.

[Bernica]

Originally Posted by olddog

I had a thought. If you sold your engine and add that to your budget of 10K, that should give you 12-14K, depending on what you can get. That should buy a top notch Windsor stroker.

If you drive over a wide elevation change, I think you should think hard on EFI. If you go with boost and have wide elevation changes, I think EFI is a must. Otherwise it is a lot of cost for little gain.

A big yup.
Sell a good engine and start on just what you want built. Tinkering on an existing build just doesn't seem to work out for what you are trying to do.
My 2c

[Cobrat24]

Originally Posted by ct clint

Your best bet is ride in a car with a charger they just keep pulling. I am stepin up to a v4 vortech and use pro m efi his suff realy works even can control the meth and nos. Had v2 but bad things happen when u abuse them lol. I would go charger and efi it realy works.

Been in a few cars with chargers, love the feel. It sounds if I went the way of 302 with supercharger with my elevation it would just make since to step up to FI. That's why I was asking about supercharged using a carb version, I don't know of anyone who has gone that route. I'm not sure 10k can get me the supercharger, FI, and side pipe fix. I'd have to price it out.

[ct clint]

There's a guy here with carb and charger he says he wish he did efi and added charger when he had more cash. Pro m racing is on line there may be better but this is pretty easy. I have had to build a new throttle body to handle the added cfm of new charger. No clue if it will work well but u can't just sit and watch lol

[Cobrat24]

Originally Posted by ct clint

There's a guy here with carb and charger he says he wish he did efi and added charger when he had more cash. Pro m racing is on line there may be better but this is pretty easy. I have had to build a new throttle body to handle the added cfm of new charger. No clue if it will work well but u can't just sit and watch lol

See that's what I am worried about, the drivability of a carb'd supercharger. I'm sure it's great in a straight wide open throttle situation like drag racing but what about everything in between?

[Dwight]

$8,000 for a 408 W with 530 flywheel HP would be my suggestion.

I stroked my 302 to 354 with fuel injection. Dyno several times 402/422 hp/tq rear wheels.

350 rwtq at 2200 rpms.


The 354 had to much tq at low rpms. To easy to spin good tires.
The next 347 I build I changed the cam to move tq up the rpm range by a 1000 rpms. Have not cranked that motor yet.

A couple of my buddies have 427 s.o. stroked in the 620 fwhp / 630 fwq range. I had no problem keeping up with them. My car was 200 lbs lighter which help. We never lined up to see who was the fastest but on a few occasion when the other guy was spanking Porches or Vett I had no problem catching up from way behind. Gave me the impression that I was a little fastest at lower speeds to 120. Full 1/4 mile from a dead stop. I think I would be very close to them at the end.
We'll never know because I wrecked my toy.
P.S. I put over 20,000 miles on that set up. Very streetable


I have driven a couple of KC 408 powered Cobra in the 530 fwhp - 540 fwtq range in Cobra. I THINK (my butts not a dyno) my Cobra was faster.

If your looking for max hp you must match the heads, cam, intake, exhaust system and the fuel deliver. Any one piece can kill you hp.

With all this being said I think the best motor for the money is the 408 KC.

I live 600 ft above sea level.
Dwight



427 with twin supercharges

[mikeinatlanta]

IMO, guys are advising without adequately taking into consideration your altitude issue. Reno is fun, fun and high, but the best roads are even higher. Boosting you motor to take back what the altitude cost you isn't going to stress it anymore than running at sea level. Boosting it a bit more isn't really a bid deal. Next is the carb. Getting a carb to work with a blower is also not a big deal, right up until you start making big altitude changes. A carb simply cannot adequately adjust for that.

You can easily convert to a throttle body injection and centrifugal blower for 10K. This option would allow a good tune at varying altitudes and allow you to increase HP incrementally as desired.

A NA carb motor will still lose big power at 5300' and even more as you hit the fun roads.

[patrickt]

Originally Posted by mikeinatlanta

IMO, guys are advising without adequately taking into consideration your altitude issue.

I agree. My Cobra spends 99.9% of its time at sea level or a couple of hundred feet above. I'm not sure it would like being a mile high much at all.

[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.

[Cobrat24]

Originally Posted by 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.

Much appreciated on the FI information. My cobra has the ford ecu with wiring in the car even though I'm carb'd. I need to get under the passenger side and see what I have and how much is there. Thinking of possibly utilizing the oem stuff with after market intake. I am very aware of the aggressive cam/vacuum issue with FI. Looking into options on that as well.

[Phill Pollard]

Originally Posted by 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.

Olddog,

Your statement isn't entirely true. You were good up until you gave the 4000 feet comment.

Speed Density systems actually DO compensate for altitude on the fly without having to turn the key on/engine off (KOEO). They do it by sensing the manifold pressure (via the MAP) every time it sees WOT (via the TPS or Full Throttle switch on a minimum function system).

So on your way up that 4000' mountain, every time you push the throttle to the floor the ECM sees atmospheric pressure (since man vac drops to 0"Hg) and notes it as BARO.

I have seen ONE instance where a customer drove his car over a very long distance with a *gradual* rise in elevation without ever having to floor the gas pedal and he got a CEL out of it. That's one instance in over 25 years of EEC work so it is rare.


Hope That Helps,

Phill Pollard

[olddog]

Originally Posted by Phill Pollard

Olddog,

Your statement isn't entirely true. You were good up until you gave the 4000 feet comment.

Speed Density systems actually DO compensate for altitude on the fly without having to turn the key on/engine off (KOEO). They do it by sensing the manifold pressure (via the MAP) every time it sees WOT (via the TPS or Full Throttle switch on a minimum function system).

So on your way up that 4000' mountain, every time you push the throttle to the floor the ECM sees atmospheric pressure (since man vac drops to 0"Hg) and notes it as BARO.

I have seen ONE instance where a customer drove his car over a very long distance with a *gradual* rise in elevation without ever having to floor the gas pedal and he got a CEL out of it. That's one instance in over 25 years of EEC work so it is rare.


Hope That Helps,

Phill Pollard

Phill,

Thanks for the correction (I don't want to put bad info out). I never studied Speed Density in great detail, but read a bit. I do not recall anyone ever pointing out that it will correct the Baro at WOT (not doubting you). That is not intuitive that they could do that because vacuum would not necessarily drop to zero at WOT. At high rpm WOT, I would expect there to still be a bit of vacuum. Otherwise the claims of a bigger TB increasing power is BS.

Rick

[olddog]

I'm guessing factory rods are in it now. Since your buying pistons anyway, get a complete rotating assembly for a 347" stroker build. ~$1200 or so.

That extra 45 cubes will be worth in the ball park of 55 Hp 60 torque.

[ct clint]

Ok if no one else is going to say it i will. That needs to come out b hot tanked and flushed out. Check bores for true Ness if good deglazed. I like to deck them also. Crank needs to be inspected good time to polish it if it's in speck. Spend the money get rotating assamably balanced. If u are using new heads they should be pulled apart cleaned and inspected. U will be surprised what u find they are mass produced not built buy loving hands. You can fit your parts together right and did your math it should be good. In the best motors round things are perfect round and flat is flat. Do some math on how much air will flow through the headers. Yours may be fine u only need to push out what goes through the carb. Sorry for the rant but don't waste money do it right. There are far smarter guys on here then me I am sure they will add.

[Cobrat24]

Originally Posted by 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.

I know Robert really well! He used to do all the machine work on my drag bike. I love that guy, he does really good work! What a small world.