You'll know to take it back a notch when the piston ringlands crack and take out the motor.

 

Why would you want heat in the exhaust side of the turbo? Wouldn't a lower exhaust temp result in a lower charge temp? Most people wrap the pipes a short length to lower underhood temps. None of the STS kits that made specifically for vehicles have wrapped pipes, nor do they recommend doing it. BTW: the blower option is still available from many companies, just not KB.

Watch the videos of the vehicles on the STS site. They ALL have severe turbo lag due to the length of the charge pipe from the turbo to the TB. One specific car that stands out is the GTO 6.0L. The car is basically n/a at the start of the race, until it hit about what sounded close to 3k rpm. That would not be a "viable" effect on a towing vehicle. Getting moving is half the battle.

If this was actually a problem, 5.4s would be affected too since they use the same rod/piston combination. The 4.6s also would be affected since the rods are the same. I'm sure you'll see S/C V10 owners chime in soon as they run 7-9 psi all day without problems. The whipple and paxton kits dont come with a high volume fuel pump or HP fuel system component, nor did they require one.

 

Heat = energy. It takes energy to spin the turbo. You want as much heat in the exhaust as possible to spin the turbo. This also reduces lag.

Well, don't forget that there is some lag in the turbo diesels, as well. My Dodge definitely had some lag in it (and running some 30 psi of boost from the factory I can see why). However the longer your piping is, the more lag you will have. I would actually say that trucks are an application where lag is acceptable, because while getting moving is certainly part of the battle, it's keeping moving that's where that power comes in, especially on an uphill.

That's exactly what my friend said when he put his Kenne Bell blower on. "It'll run 6 psi all day with no problems." Trust me, an engine running that kind of boost "all day" literally takes a lot more than most people think. Most of the people driving around with these blowers I doubt are getting on the boost all that often. If you take the total number of hours that they're on boost in the duration of ownership, it will be lower than the number of hours I'd end up being on it for one towing trip, if I was really using it. I know, people will insist that can't be...

Anyways, I've made my point. I've also stated that I may very well turbo my truck next spring if I get the urge anyway, but if I do so you better believe I'm putting a boost gauge in and staying off the boost while towing.

 

the basic stuff:

JLT cold air intake
hooker longtubes, offroad x pipe
borla stinger catback
SCT chip/dyno tune
and only thing out of the "ordinary" was a meziere electric water pump (which was quite a nice surprise).

went from 273.3 and 298.5 to 323.5 and 331.x (can't remember exact torque)

 

Depends on which of the mod motors you're talking about The higher compression ones will do much better with nitrous than boost, while the lower compression ones, like the V10s, 5.4s, and 2/3v 4.6s will be doing much better with boost than nitrous... nitrous loves compression, boost quite the opposite.

 

I understand that but, you're talking about a small amout of heat that is dissipated. You won't lose exhaust pressure (which drives said turbo) with lower temp exhaust since the turbo acts as a restriction resulting in the pressure we're discussing. Heat is only part of the energy required, exhaust pressure is the main driver.

Diesels don't lag from idle to 2800-3000 rpm. Lag is acceptable but not desirable in any truck, hence "variable vane turbo" employed by ford as an attempt to alleviate lag. You WANT the power off idle, keeping moving requires a relatively small amount of power in comparision to starting the movement.

V10 supercharged industrial engines do it everyday, and describe "alot more"... Alot more of what? Fuel? That is a given. Also, since you are using the "boost" every time you accelerate with a blower, I'm sure "they" use the boost more in a week of commuting than your one towing trip.

Good luck with that, since you will be towing, your engine is stressed, applying exhaust pressure to your turbo, making boost.....

 

All the drag racers wrapping their pipes up to the turbo must be crazy? Keeping teh heat in the pipes keeps the energy in it and spools the turbo better from my understaning.


Diesels dont spool instantaneously either? Granted a rear turbo may take a second or two long to get up to speed, it will accomplish waht needs to be done in short order.


SVT lightnings did not use stock pistons/rods/rod bolts in the lightnings form my understanding. Intercooling is also a large factor in how much boost you can run. A well intercooled setup can run 50% or more boost in many applications. Look at the Procharger Vs. Vortech fights of yesterday. As far as fuel, I really can not believe the stock fuel pump can keep up with 7-9lbs of boost. Let alone the injectors. Duty cycle would be be well beyond 100%, and to be safe you try to stay below 80% duty cycle. Stock injector just does not move that kind of volume. Period.

 

Completely right. I was just talking about the ones in trucks though considering what site we are on. I still think modulars should be built for boost more then for nitrous for optimal results though. Granted boost is much more $ though.

 

One more quick post to back up my fueling issue argument. Again, you do not want to go above 80% duty cycle, running stock fuel pressure, and assuming 10 injectors, and lets be nice, lets say we are boosting 7.35 PSI aka 1/2 bar (barometric pressure). Now in a motor with supporting mods (mainly exaust and cam in my opinion) you should see 50% or close to that much of a HP increase. As you are forcing 50% more air in. Now that should put you around 465HP (you would actually be more due to your new free flowing exhaust and cams and other mods, but again, I am being nice to you). So, we need to feed 465 horses, with 10 injectors, not going over 80% duty cycle (how long the injector is held open) with the stock fuel pressure (43.5 is the common pressure, please let me know if the V-10 fuel system runs higher like a GM LS engine family does), and we are feeding a turbo motor, so it is more fuel thirst then a supercharged, or naturaully aspirated motor to remain on the rich side of stoich for your turbo (stoichiometric aka 14.6 parts to 1 part fuel in a gasoline motor, ideal air/fuel mix on a naturaully aspirated motor), so we will go with teh median value typical of a turbocharged engine and plug in .63 BSFC (brake specific fuel consumption) and we get a number bakc that is very close to 36lbs as teh recmmended injector. Now since I was leaning on the easy side for you, and you were talking more like 9PSI, I would say a 42lb injector would be more ideal, if not larger.

Now, we have a stock fuel pump probably pushing what 180-190 litres per hour? (thats the common output of most large engine stock fuel pumps) now unfortunatly this will be no where near what you need to feed 10 injectors of this size. Heck they sign off around 350-400HP max if your lucky usually. a 255LPH walbro drop in replacement will take you to around 500 or so wheel horsepower if you lean on it. So even a larger dorp in is gonna be taxed to try and feed this motor you just dreamt up.

I wont start on boost refferenced fuel pressure regulators as I have confused enough people already.

Reffernece RC Fuel Injection for lots of great calculators and general reading on injectors and fuel systems.

 

1. A rush of power beginning at 3000 rpm is not going to do a truck that is towing something any good. If it can't get the load moving, it won't hit 3000rpm, not to mention take forever to get to that 3000 rpm. Essentially, that turbo is an exhaust restriction until it created boost. A lag of that amount would be worthless in a heavy duty truck. Diesels have some lag, but not 3000 rpm worth, thats damn near redline for them. The rpm/power range is completely different between the two engines, so using a diesel as a comparison isn't viable.

2. Idle to 3000 rpm is not short order.

3. We aren't talking about lightnings or any other svt product. Basic 4.6 used the same rods as the 5.4 and 6.8. 6.8 used the same pistons and rods as the 5.4.

4. Look at the STS site and see if you can find a single pic of any vehicle with the exhaust wrapped all the way to the turbo. You won't.
They claim the rear turbo kits don't need an intercooler due to the fact that the exhaust is cooler way out back, they compensate for heat loss with a/r and impeller pitch but it also creates lag. Plus, the distance back to the engine from the turbo, the charge has time to cool through the 6+ feet of intake tubing.

I agree with the heat providing more kinetic energy to push the turbo but, you don't lose alot of heat even with the pipe unwrapped. Run your truck once on a 1-2 mile trip and try to touch the exhaust tip. You'll get burned. All that heat isn't lost, it may be reduced somewhat, but isn't lost.

 

1. Hav eyou ever heard of brake torqueing a car? Basically holding the brakes and hitting the gas to spool up the turbo. When you have a big load holding the truck, it is going to allow it to spool and make the power! Just like a diesel pulling a huge load!

2. You will get boost off idle with a slight delay if you size your turbo correctly. Research is key, you apparently have not done much.

3. So a SVT lightning (the big mod motor built for boost) used stock rods and pistons? Really?

4A. Again, do some research on these kits other tehn from the people taht are trying to sell you something. These kits off teh shelf are VERY incomplete, and will build minimal power. You have to make some big changes to see any real power gains. Wrapping teh exhaust is one of the big ones. Basic physics comes into play here.

4B. The charge pipe does have a mild intercooling effect, but nothing near what a front mount intercooler full of bugs can do. Also, when it heats up from a long pull as in towing, how much do you think that pipe stuffed under the car will cool with a hot engine, trans, coolers for those, a/c condensor, hot exaust etc etc etc heating teh air up in fornt of it?

5. (even though you didnt number it) how in the world is the hot exaust side, not working as an even more effective intercooler, then the cold side that you claim does such a fantastci intercooling job?

6. (cuse I wanted to add a 6, and I can) You either have a vested interest in this company, you own, or have a friend that owns one of these kits, did MINIMAL researched, research from a heavily biased source no less, and appear to have basic to moderate general knowledge of this subject at best. Research the product as its used in real life applications, talk to teh people that run em, that modify em to work better, taht push them to their limits and set new records regularly with this style of turbocharging. When you have people doing real life research, with dyno, and track numbers to back their claims, then you can come back and argue with me some more.

 

This is why I've stopped participating. I work with turbochargers every day for a living as an engineer, and have done literally thousands of hours of dyno testing on the engines I deal with. I don't need to argue with people who don't want answers that they don't like.

 

The 6.8L is just a 5.4L with two extra cylinders. I'm using parts off of the Procharger 5.4L supercharger kits to make one for my V10. A local performance shop will be helping me with tuning and such. Here is a picture of the supercharger bracket on my V10. I have also purchased a powerstroke intercooler for a direct bolt in and keep things cool under boost. Planning on running 9-12psi.

 

Keep us updated on your progress and good luck. The V10 is new to me and seems to have all I need stock, but has been interesting reading.

 

1 Agreed.

2. Oh cmon, you mean not all turbos make power like a supra? 120hp/tq till 5000 rpm and then 1400hp/tq? :P

I agree that sizing the turbo correctly is key, and I think that's where a lot of the confusion comes with the STS kits. The lag issue is brought up every time, and STS has said numerous times, these kits are designed such (read: smaller turbos) that they reach boost as soon as a regular kit, they just don't make as much peak boost as a regular kit - a good tradeoff most people are willing to make considering the price differences. For those looking for all out track performance, a conventional kit would be much better suited, indeed.

A "small" turbo on a big azz engine like a V10, will spool up in no time. I mean, everyone knows, V10s caused global warming, and set polar bears on fire with how much exhaust gasses they make.

3. Forged pistons, but powdered toothpics for rods if I'm not mistaking. Crank is cast as well. They're not as built up as the 03 cobra motors or the gt500/GT motors, as much as we'd all wish they were