[GreyDiesel]

here is my situation: I bought the Mustang GT V8 because I wanted a V8 power and sound. Fun times. I did a ton of research, and the Mustang GT is the car for me. I bought it, then took it up to my local track and pulled a 14.8. That is because my local track is at 5800ft. I did not know the altitude would have such a huge effect. It is bothering me. I have this great car with a great engine, but really, if I am honest, I am probably pulling something like 250hp at the flywheel way up here in Denver. We just bought my wife a beater 01 volvo with a 5 cylinder turbo, and I swear, that thing is nearly as fast as my GT. I was at a local road course getting whooped up on by a BMW 1-series. The 1-series has a turbo, so its actually getting much closer to factory power numbers even up high. So, my questions, is there a good, mild turbo I can bolt on that will get me into the 320hp range? I am not looking to push the limits of the engine, just want something that will get me into the performance most people get with a NA 4.6L at sea level. I know there is a procharger mild supercharger, but I am concerned about the loss of low end torque on those.

[302GTS]

TBH, our little Mustangs love turbos, but the bolt-on kits are normally quite expensive. I'd suggest looking into a Vortech kit for your car, as those have been known to give around 100hp on a basic kit and, with a solid tune, your car would run great! The altitude's a tough thing I'm sure, but it can be overcome!

[walter]

Before going the forced induction route let me ask you have you dyno tuned your vehicle at a local shop to compensate for the thin air you breathe? Your poor car is starving for oxygen and leaning out since the spanish oak ECU is designed for processing speed not adaptability.

[lightblade]

Altitude is relative. If that bmw was beating you at high altitude it would do the same at low. Turbos and superchargers still under-perform at high altitude/low oxygen. Only way to overcome the air is to make your own atmosphere(Nitrous). That being said a turbo/supercharger adds more power reagrdless and is safer and more reliable. If your staying close to stock and want a power adder and dont want to spend alot, go with a vortech non-intercooled 6-8 psi for 3 grand get a good tune and be done with it.

[lightblade]

Originally Posted by walter

Before going the forced induction route let me ask you have you dyno tuned your vehicle at a local shop to compensate for the thin air you breathe? Your poor car is starving for oxygen and leaning out since the spanish oak ECU is designed for processing speed not adaptability.

Even if the density of the air(thinner) is being seen by the maf and causing the car to run lean on a stock tune(which is unlikely). If the cars running lean then its actually making more power.

[ct07gt]

At high altitude it will not be running lean, it would run rich because there is less air available.

Turbos are often not significantly affected at high altitude, the turbo will make boost until the blowoff releases the excess. The blowoff works at a set pressure, so at high altitude the turbo would have to spin at a higher rpm to make that same boost, but it would still make that same amount until the turbo's capacity is exceeded. So a smaller turbo would be affected at a lower altitude than a large one. That is my understanding of it, if I am wrong someone can correct me, but I am almost positive that a turbo does much better than a NA car at altitude.

[Al Guapo]

Here's some pics I took during my NJ-CA road trip. Some proof of how much altitude affects your car just at idle.



5,000 ft in Zion NP, UT



10,000 ft in Bryce NP, UT



My vacum back home (Jersey) is at sea level at 26. I don't have a pic.

In Bryce there were times when I couldn't go up a mellow hill without going into boost!

[ct07gt]

Could you still reach the 9 lbs of boost under full throttle?

This is the article I was basing my previous post on.
http://www.roadandtrack.com/article....rticle_id=5030

[GreyDiesel]

thanks for the info everyone. I figured this would be an interesting topic to put out to the group. I have not been able to find much info on the subject of power and altitude. Here are the things I know:

Stock Mustang GTs pull 15s flat at the local track (Bandimere). That is compared to 13.8 at sea level. I think that is a pretty significant difference. If you run those times in a standard HP calculator for a 3500lb car, your looking at 240hp.

I was talking to a pilot friend of mine, and he told me you NEED a turbo prop plane to fly over the Rocky Mountains. A naturally aspirated engine will not make it over the mountains, so turbos do preform better at high altitude.

Ford just ran a publicity thing for the ecoboost V6 in a lincoln, that match the performance of some german NA V8s up here on Loveland pass. Now, the ecoboost is a turbo, rated at 350hp, the V8s are NA, rated at 420hp, but... up in high altitude, the turbo won out. So its clear that a NA engine will be more negatively effected by altitude.

You know those beasties they run up pikes peak? They have upwards of 1000hp. That is, they are rated at 1000hp at sea level. By the time the car makes it to the peak, they are looking at only 3-400 hp because there is no air. (Those are definitely turbos), but the point remains that altitude kills power. And, you never see a NA engine posting great times climbing the peak.

@walter - I have not had a custom tune from a local shop (dont know of any), but I do have a C&L Racer intake and tune. The tuner allows me to fiddle with the fuel mixture, and I have, but not seen any significant changes.

[forensicsteve]

Research nitrous some. You don't need a huge amount...just a small shot may suffice. You'll deliver more oxygen to the engine. With forced induction, you will still be working off the available oxygen which is diminished at high altitude.

In the deep south with oppressive humidity, we don't race during the summer months for the same reason...two many H2O molecules and not enough O2...all the forced induction cars at the track suffer.

[Al Guapo]

Originally Posted by ct07gt

Could you still reach the 9 lbs of boost under full throttle?

All day. Only thing was the car still felt like it was falling on its face up top.

[GreyDiesel]

Originally Posted by forensicsteve

Research nitrous some. You don't need a huge amount...just a small shot may suffice. You'll deliver more oxygen to the engine. With forced induction, you will still be working off the available oxygen which is diminished at high altitude.

In the deep south with oppressive humidity, we don't race during the summer months for the same reason...two many H2O molecules and not enough O2...all the forced induction cars at the track suffer.

Interesting idea, thanks for the input. I guess I had not considered nitrous, because I saw it as a quick way to blow-up your engine. If its safe though, yeah, makes a lot of sense. I'll look into it...

[02GTRX]

Comparing it to a 1series isn't helping your situation sea level or not. A 300+hp twin turbo bmw 1 is alwalys going to put a whoopin to a stang.
Posted via Mobile Device

[NastyStang113]

Originally Posted by walter

Before going the forced induction route let me ask you have you dyno tuned your vehicle at a local shop to compensate for the thin air you breathe? Your poor car is starving for oxygen and leaning out since the spanish oak ECU is designed for processing speed not adaptability.

Come on now ... The Spanish Oak processor can't adapt to the air density in Denver. That's hilarious!

[GreyDiesel]

Originally Posted by 02GTRX

Comparing it to a 1series isn't helping your situation sea level or not. A 300+hp twin turbo bmw 1 is alwalys going to put a whoopin to a stang.
Posted via Mobile Device

I dont think so. The two cars are pretty evenly matched at sea level. I think the turbo, in this case, made most of the difference. I could actually catch-up in the corners, and then he would just zoom away in the straights. I have an Steeda suspension on my car, so the suspension weakness of a regular stang have been ironed out. Then, I've also got an intake and tune, so I would be looking at 330hp (again, at sea level). That puts our power to weight in the same ballpark, (at sea level) probably a tad on my side, especially when you consider torque to weight. Now, the 1-series had a few aftermarket parts as well (suspension, intake and tune, and... tires). If the turbo was not the winning factor it was the tires. Given that I could catch him in the corners, I think it was the turbo.

There was also a 350Z on course, and I passed him like he was stopped. The 350Z is another car that you might think would be competitive, but a stang is hard to beat. (see: 2009 road course championships Ford Mustang captures Grand-Am Koni Challenge and SPEED World Challenge titles — Autoblog) There are obviously driver skill, and many other factors. Maybe the 350Z was doing tuning tests and not pushing it? Or maybe, as I suspect, the 350Z was being punished by my stang because we are both NA engines and therefore both equally down on power. The point is, a Mustang is plenty capable of taking many of the cars on track, including a 1-series, and you've got to try while your out there....

(AT SEA LEVEL!)

[GreyDiesel]

I want to sort of restate my question for clarity, and hoping to make another effort at finding an answer. The only turbo kits I can find are very expensive and huge (see helion). They make huge power, but would also require a forged engine parts if used on daily driver for 100k miles. I am just looking for a small turbo, that hopefully would be cheaper, and would not make enough boost to blow my engine, but just get me up to "normal" power range here in the mountains.

Does anyone know of a company that makes small turbos for mustangs?

[ct07gt]

You could try a non intercooled centrifugal; they are relatively cheap. Then get a dyno tune to work with your altitude issue. I have not heard of anyone selling a small turbo, I think most of those kits are catering to people looking for big horsepower.

[forensicsteve]

You can use a decent size intercooled turbo and with a conservative tune...you may never need to forge the motor or reinforce other parts. We bought a 67mm turbo from Powerhouse. This is their base unit...it's a little larger than some other base heads and certainly capable of 700-800hp with a built motor...but you can just use the 9lb spring and stay safe all day, with your stock engine, rearend, transmission.

We have been dealing with Powerhouse for over 2 years now. Upgraded to their larger 76mm and pumping out 22 lbs of boost. Call Mike over there (814 774 4966) and just have a chat with him...very easy to talk to and a straight shooter. He'll tell you what you need and just as important...what you don't need. Mention steven from south Louisiana, if you like. He's building us a custom driveshaft right now to fit our GM 2 speed powerglide transmission that's in our mustang racecar.

[retfr8flyr]

Another option is Turbohorsepower.com . Give Jim Napier a call and he can answer all you questions and make you a kit for your needs at a good price.


Earl

[GreyDiesel]

hey thanks for all the tips. This is exactly what I am looking for.

I am not quite ready to buy, still in the research phase, but turbohorsepower and powerhouse are exactly what I had in mind. Hopefully... I'll have the funds to buy from one of them come spring.

[bigcat]

are you looking for track specific performance or street performance as well. i dont know your track, but 4.30s work great for me on the street here at 7200 feet. the feel of the car is about the same as 3.55s at 1100 feet elevation. however, gearing may not be a good thing, depending on your tracks setup.

[GreyDiesel]

good point. I'll keep that in mind. If I cant afford a turbo, gears are a very likley substitute. Right now I have the 3.31s, so... I may actually own the slowest S197 GT in the country.

[bigcat]

imagine the horror of going from 4.30s to 3.31s like i will be doing this winter. i will be finally installing that GT500 rear axle i bought from your neck of the woods this summer, and they come with 3.31s. that will be the ultimate SOTP killer.