HP upgrades, but which one?!

[abolfaz]

I've read through a lot of old threads about increasing the HP on our cars, but which is the best? ECU reflash + pulley, but who would you use to do it (florida), ECU reflash + new blower, ECU reflash + new blower snout & pulley? What mods do we know of that have given the best gains with the least $? (hennessy can find another sucker for that $40k package...)

 

[50 BMG]

Chip + pulley + dyno/treet tuning is gonna be the best bang for the buck. Just make sure you go to the right place.

This is what I'd do personally.

Power:
Chip, custom cams, ported heads, overbore, SW headers no cats. No boost increases.

Misc:
Diff cooler, engine cooling upgrades, bigger front tires (and perhaps a softer treadrated tire than OEM all around), and spring/shock swaps for road course.

 

[piko6]

if you are in florida ..

hp performance in jacksonville has done 4 or 5 cars now an dhas good knowledge of your car

 

[barondw]

Adding such things as headers, cams, supercharger, etc. are almost a waste of money based on the efficiency of the stock pieces IMO. Also that would immediately void your warranty.

Very few if any owners want to be on the hook for a $27,000+ new motor if something happens. Wish lists are nice but a major bunch of realism needs to be placed in the equation.

A pulley, a chip or computer re-flash, removal of cats seem to be the logical way to go. Depending on who does the work the re-flash or chip should not be detectable by Ford. Also gutting the cats should not be detectable if done by a compentent speed shop. The cats are probably the major restrictor on the stock vehicle. That is why Ford gutted them on the press vehicles used during the pre-launch hoopla. Don';t forget to add the trans/axle cooler which should have be standard equipment.

As posted in another thread make sure you can handle the stock vehicle in all types of situations before adding more torque and power. Remember there are pictures of crashed GT's on the forum. All those guys made some type of driving mistake, yup driver error. There is even a thread on a couple of Ferrari Enzos that were split in half from high speed accidents. Don't join their club.

:cheers

Dave

 

[dbk]

Abolfaz,
Heffner Perfomance in Sarasota. (941)359-0900. Give Jason a call and he'll explain what can be done and what to expect, whether you want the basics or some truly crazy stuff. The definition of a competent shop.

I think Chad on here got about 100rwhp out of the basic pulley tune intake stuff up there.

 

[50 BMG]

Adding such things as headers, cams, supercharger, etc. are almost a waste of money based on the efficiency of the stock pieces IMO. Also that would immediately void your warranty.

Any of this chip & pulley business will immediately void a warranty if it's caught. Thinking otherwise or that Ford can't map a flashed computer is foolish IMO. The only 100% way you're going to get away with it is doing a snout or total blower swap and having a brand new backup PCM, so that the stock blower/parts have no sign of a pulley removal and the PCM is virgin. Unless you guys are getting special treatment from Fords warranty department :banana , exhaust mods are the limit of warranty safety.

The stock cams are the only questionable thing on the longblock and would be the 2nd thing I'd swap out. Quoted from John Mehovitz on Modular Fords:

"It is true that the Ford GT uses 5W50 oil, HOWEVER, the lash adjusters are specifially calibrated in that engine for that oil. AND I can tell you for a fact that 5W30 does not work in the Ford GT because I already did that on the dyno and it lost 15 hp on the dyno back to back. As it turns out the reason it lost hp was the thinner oil is more easily compressed in the lash adjuster and the engine effectively thinks the cam is smaller because it is now easier to depress the lash adjuster than to open the valve. The cam profile is the problem in that specific application. The thicker oil is the band aid."

http://www.modularfords.com/forums/2003-2004-mustang-cobra/crower-cams-45339-post468629.html

Just my opinion, but I'd rather increase the volumetric efficiency of a FI system than just throw more boost at the engine.

Very few if any owners want to be on the hook for a $27,000+ new motor if something happens.

A pulley, a chip or computer re-flash...seems to be the logical way to go...

Pulley/chip will put you on the hook harder and faster than just about anything else you can do to your engine.

 

[nota4re]

I'll "write out loud" about my intentions...

I'm going to order and hopefully have the shop manual, floor mats, and clear bra templates here BEFORE the car arrives.

Mechanically, my first priority will be the transaxle cooler. I think Ford should have done that with the base car but whadaya want for $150K?

Next up will be the exhaust/headers/cats. Three objectives here and I hope within the next few months we'll have some additional choices. First objective is purely a subjective one - I want the car to be a little louder. It's not going to be either a daily driver or a long-run cruiser so I can stand a little more interior noise. Second objective is HP. I definitely think headers will help performance and I'm hoping to mate that to a good exhaust system sans cats. While improving the exhaust system, I will definitely add 1-2 add'l "bungs" at the collectors or just aft.

When the exhaust system is in order, I'll incorporate an on-board wideband data logger using the aforementioned exhaust bung populated with Bosch wideband sensors. This will allow me to collect a/f data across the rpm range to see where Ford has this dialed in at.

Next up will be increased boost and some mild computer mapping to maintain af's. I have a good friend who is a friggen' rocket scientist with the Ford computer. He knows it inside out, backwards and forwards and sideways. The GT motor is unique (in the Ford family) because it utilizes two injectors per cylinder. I have alread discussed this with my friend and we believe we know how they are managing this programatically. Anyway, with some carefully planned boost increases, I am very confident that we can do the proper tuning to maintain stock Ford A/F numbers. An added 100HP will be the end goal and I think quite attainable without having to do anything to push the envelope. It may be necessary to datalog fuel rail pressures if the AFs aren't completely predictable with the ECU mapping.... but we'll cross that bridge when we come to it.

Suspension-wise, I will have my eye out for a system which provides for about 1" lowering of ride height.

I'm a very patient, methodical tuner. It may be 12-18 months or more before I have the engine mods done but I know it will be done right.

 

[fjpikul]

Is "programatically" really a word?

 

[satx]

Very few if any owners want to be on the hook for a $27,000+ new motor if something happens.

just a side note......obviously IF something were to happen to your modified motor you wouldn't necessarily have to purchase a completely new engine. Rebuilds will usually suffice :wink

 

[Black2003Cobra]

The purpose of cams or head porting, etc., is to increase power and torque of the motor via an improvement in the intrinsic volumetric efficiency of the engine, VEe. Normally, an increased volumetric efficiency means the engine will ingest more air (and proportionate amount of fuel), and hence make more power. An engine with a positive-displacement supercharger, however, will not respond the same way to volumetric efficiency changes as an NA engine.

This is because at WOT, the positive-displacement blower is the primary control of mass-air flow into the engine. This is true at all rpm. By definition, a P-D SC forces a fixed volume of air per revolution, i.e., it is a constant volume machine. Hence, the mass-air flow rate will be fixed (ideally) at any given blower speed (rpm) and inlet air density. (Density times control volume = mass). Although there are some second-order effects that will result in some gains, (via reduced boost pressure thereby increasing the overall mechanical efficiency), they won’t be as great as on an NA motor.

Bang for the buck, just shoving more air (and fuel) in by spinning the blower faster is what does the trick.

http://www.modularfords.com/forums/...positive-displacement-supercharger-41735.html

 

[californiacuda]

I'm confused, after all of the big words and formulas, what's your point.?

 

[californiacuda]

I can think of many things that could drastically change how well an engine works, in addition to spinning the blower faster. At some point any blower(as it is spun faster) will exceed its efficient capacity and start requiring more power to spin it and produce much hotter air.

An efficient cam, proper tunning, increased static compression, higher octance fuel, more efficient way of producing boost, lower charge air temp, I don't know, there any too many paths to power to simply say that only 1 is the best.

 

[Black2003Cobra]

You'll have to bear with me on the formulas, et al. I'm an engineer.

And I honestly mean no offense, but I thought the point was clear? It’s what I wrote right above the link? Best bang for the buck is to just spin the blower a little faster. (How much does a cam change, head porting, LT headers, etc cost? How much does a pulley cost?) There’s nothing wrong with increasing the overall mechanical efficiency of the engine…it’s just expensive.

Clearly one can spin the blower too fast. Obvious and true. After a point, it would make more sense to upgrade the blower. But I wasn’t suggesting getting carried away. With a stock lower and say a 2.8” blower pulley, you won’t be overtaxing the stock SC. That’s what I had in mind. I suppose I should have been more clear.

As far as the other things mentioned, here’s my view.
Cams – See comments above. Besides, the stock heads and cams on the GT already flow really well.

Proper tuning – Absolutely. Advancing the spark (up to the point of MBTT) or leaning out the AFR (up to a little below stoich) will get you a little more power. But it also pushes you closer to the knock limit, and can therefore be dangerous. To be fair, so does increasing manifold pressure. So I look at tuning from more of the safety point of view, i.e., to avoid knock. From the performance point of view, I think one will find that you gain more power per pound of boost than you do per degree of timing. In other words, it’s more effective and safer to increase boost and back off on timing a little, and/or increase the AFR. But clearly there are limits. Again, I’m not trying to suggest getting carried away with boost.

Higher octane fuel – Actually, if you don’t change anything else, increasing the fuel octane will reduce power, since it slows the flame velocity. The purpose of running a higher octane fuel is to avoid knock when you do things like…increase boost.

Lower air charge temp – Yes, but only if it’s at the inlet of the supercharger. Once the air is compressed, raising or lowering its temperature won’t increase its mass (or density). Conservation of mass applies. So same mass of air => same mass of fuel => same amount of indicated power. A lower IAT2 is safer, however, in terms of knock. (I am not sure about your cars, but on the Cobras the computer will pull timing if IAT2 gets above a certain limit, so that would impact power.)

I hope this all makes sense. :cheers

 

[californiacuda]

Thanks for helping those of us who aren't engineers.

 

[B O N Y]

You'll have to bear with me on the formulas, et al. I'm an engineer.

And I honestly mean no offense, but I thought the point was clear? It’s what I wrote right above the link? Best bang for the buck is to just spin the blower a little faster. (How much does a cam change, head porting, LT headers, etc cost? How much does a pulley cost?) There’s nothing wrong with increasing the overall mechanical efficiency of the engine…it’s just expensive.

Clearly one can spin the blower too fast. Obvious and true. After a point, it would make more sense to upgrade the blower. But I wasn’t suggesting getting carried away. With a stock lower and say a 2.8” blower pulley, you won’t be overtaxing the stock SC. That’s what I had in mind. I suppose I should have been more clear.

As far as the other things mentioned, here’s my view.
Cams – See comments above. Besides, the stock heads and cams on the GT already flow really well.

Proper tuning – Absolutely. Advancing the spark (up to the point of MBTT) or leaning out the AFR (up to a little below stoich) will get you a little more power. But it also pushes you closer to the knock limit, and can therefore be dangerous. To be fair, so does increasing manifold pressure. So I look at tuning from more of the safety point of view, i.e., to avoid knock. From the performance point of view, I think one will find that you gain more power per pound of boost than you do per degree of timing. In other words, it’s more effective and safer to increase boost and back off on timing a little, and/or increase the AFR. But clearly there are limits. Again, I’m not trying to suggest getting carried away with boost.

Higher octane fuel – Actually, if you don’t change anything else, increasing the fuel octane will reduce power, since it slows the flame velocity. The purpose of running a higher octane fuel is to avoid knock when you do things like…increase boost.

Lower air charge temp – Yes, but only if it’s at the inlet of the supercharger. Once the air is compressed, raising or lowering its temperature won’t increase its mass (or density). Conservation of mass applies. So same mass of air => same mass of fuel => same amount of indicated power. A lower IAT2 is safer, however, in terms of knock. (I am not sure about your cars, but on the Cobras the computer will pull timing if IAT2 gets above a certain limit, so that would impact power.)

I hope this all makes sense. :cheers

great post, I appreciate it very much, so many possible decisions to make, so much to weigh, thank you!

 

[SLF360]

Another thing, if you mod, be careful to not drive at too high loads at too little revvs (underrevving), as knocking results.... Comparable to the sound you hear when driving a Diesel, hence easily recognizable.. If you have a tendency to cruise at low revvs, and then accelerate without downshifting, taking in a bit higher octane fuel could avoid you ruining prematurely a great engine..

 

[Craig]

This being a "Modern" car, I would expect it to have a knock sensor and reduce the timing to aviod detontation. Does anyone know if this is true? I was happy to learn the the timing is reduced at 240 degrees coolant temp in order to prevent overheating.

Craig

 

[AMB]

Craig

"NO" Knock Sensors!!! ONLY for TEMPS !!!

AMB