Bigger turbo, less stress?

[Interceptor]

Thinking about skipping the performance pack upgrade from Ford and installing larger turbo for this reason, right or wrong?
If I install a larger turbo there will be less stress on engine, turbo, safer tune since HP will come from larger turbo instead of edgey tune?
Plan on only 350 RHP. Not wanting a race car, just want a good dependable grocery getter that has a big set.
This isn't about the money or warranty, its about being fast and dependable, and daily drivable.
If this has been discussed in length before, link me please

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[offcamber]

You could leave the stock turbo and go with lighter wheels and Michelin Sport Cup tires. Start reducing weight (rotating mass) and put on some sticky gumballs and you will go faster. Add a more efficient inter-cooler and 3" catback exhaust and you will have a quick but reliable daily driver. As soon as that big turbo goes on then Ford will refuse any warranty issues with your drivetrain which you said isn't a concern but It's still a $3,000 gamble.
I'm also in the Low Country so anytime you need help with your car hit me up!

 

[69mach1-395]

IIRC, bigger turbos may be lazier at low rpms with more power at high rpms...

 

[Bull Run]

It's generally true that bigger turbos can flow more air at the same boost level. For example, when I swapped in the VS2+ turbo and updated the tune, my max boost level stayed the same (around 26 PSI) but the car picked up about 30 estimated HP (per AP). Since VS2+ isn't what I'd consider a large turbo, I hardly notice any lag over the stock. I dynoed the car earlier this year and got 358 WHP on a Mustang dyno on 91 oct with WMI (50/50 mixture), so it should be around 400 WHP on a Dynajet dyno since Mustang dynos read about 10 to 15% lower.

Per Adam, 91 oct with WMI at 50/50 mixture is similar to running E30. If you look at my dyno graph, the power keeps climbing until near the red line, whereas dyno graphs for stock turbos usually show sharp drop in power after around 5,500 RPM. While it's possible to hit 400 WHP with a stock turbo, it requires E85 and large timing advance to make up for lack of airflow at high RPMs. Stock turbo will be pushing a lot of hot air at that level and aside from questionable longevity, it probably won't do too well in the Phoenix metro area where it gets to near 120 degrees during the summer.

Unless you have bad gas in your area, 350 WHP should be doable with the stock turbo. Are you already at FBO? Another recommendation is to upgrade your tires and chassis/suspension to increase traction before considering a turbo update. I made the mistake of doing all the power mod first, and it actually made the car less fun to drive because I had to constantly watch my throttle to avoid a Cars and Coffee incident.

 

[Interceptor]

Thanks for your build link Bull Run.very interested in exhaust build.
I completely understand concern of suspension upgrade that are needed and why.

So if I understand correctly these are my choices, which include intercooler CAI
1. Ford power pack tune which I feel I will just give me a bump in power, similar from unleaded gas to premium gas. Money spent for parts that can not be used in upgrades and 18% cost of turbo upgrade
2. Have car Dyno tuned and squeeze out the horsepower with stock turbo, hoping I got a good tune so no blow
3. Install larger turbo with conservative tune, catted down pipe. Maybe exhaust system as Bull Run has done.
I know more hp is left on table but as I say before just feel larger turbo will make it all work under less load, not trying to have fastest car

 

[ElAviator72]

I know of at least one guy who did a big turbo and went back to the stock turbo. IIRC, he used one of the Vargas kits. It resulted in a great quarter mile machine, but was terrible for daily driving (turbo lag, no low end).

 

[xraystyle]

Nah, dawg. The Ford tune isn't just like running better gas. It completely changes the feel of the car. It pulls all the way to the redline instead of falling on it's ass around 5500 RPM. Peak HP and torque is higher as well. Feels like a completely different car.

1. Ford power pack tune which I feel I will just give me a bump in power, similar from unleaded gas to premium gas. /QUOTE]

 

[5.0yote]

It's generally true that bigger turbos can flow more air at the same boost level. For example, when I swapped in the VS2+ turbo and updated the tune, my max boost level stayed the same (around 26 PSI) but the car picked up about 30 estimated HP (per AP). Since VS2+ isn't what I'd consider a large turbo, I hardly notice any lag over the stock. I dynoed the car earlier this year and got 358 WHP on a Mustang dyno on 91 oct with WMI (50/50 mixture), so it should be around 400 WHP on a Dynajet dyno since Mustang dynos read about 10 to 15% lower.

Per Adam, 91 oct with WMI at 50/50 mixture is similar to running E30. If you look at my dyno graph, the power keeps climbing until near the red line, whereas dyno graphs for stock turbos usually show sharp drop in power after around 5,500 RPM. While it's possible to hit 400 WHP with a stock turbo, it requires E85 and large timing advance to make up for lack of airflow at high RPMs. Stock turbo will be pushing a lot of hot air at that level and aside from questionable longevity, it probably won't do too well in the Phoenix metro area where it gets to near 120 degrees during the summer.

Unless you have bad gas in your area, 350 WHP should be doable with the stock turbo. Are you already at FBO? Another recommendation is to upgrade your tires and chassis/suspension to increase traction before considering a turbo update. I made the mistake of doing all the power mod first, and it actually made the car less fun to drive because I had to constantly watch my throttle to avoid a Cars and Coffee incident.

You can do near 400wheel on the stock turbo, its running it a little hard but not that difficult to do. I am running anywhere between 355-376 and 406TQ on 93 pump with my WMI setup. in rediculous hot and humid weather right now in BOS.

I got way better top end out of my Precision turbo kit when I had it at a loss down low, I did make more HP but where it made it was not realistic for a daily driver. After the fun of the rocket ship wore off. I went back to the stock turbo but retained the intercooler, 3" catless DP, cat back exhaust, tuning and WMI. Making fairly close to the big turbo power at about the same PSI just my graphs are completely different where the power comes on.

To be honest its more than enough power, then as stated above remove some of that rotating weight. (wheels, balance shaft etc.)

 

[Darkstar]

Nah, dawg. The Ford tune isn't just like running better gas. It completely changes the feel of the car. It pulls all the way to the redline instead of falling on it's ass around 5500 RPM. Peak HP and torque is higher as well. Feels like a completely different car.

Yep, it's not a subtle change.

 

[Bull Run]

I know of at least one guy who did a big turbo and went back to the stock turbo. IIRC, he used one of the Vargas kits. It resulted in a great quarter mile machine, but was terrible for daily driving (turbo lag, no low end).

Original version of VS2 had single scroll design, which is great for top end but noticeably increases lag. They came out with the twin scroll version later due to the complaints of lag. I have the TS version as it's still good enough to max out the stock block. I still lose traction if I attempt to do near-WOT at stop or slow roll even with the 285/35/19 summer tires on a hot day.

 

[Bull Run]

Thanks for your build link Bull Run.very interested in exhaust build.
I completely understand concern of suspension upgrade that are needed and why.

So if I understand correctly these are my choices, which include intercooler CAI
1. Ford power pack tune which I feel I will just give me a bump in power, similar from unleaded gas to premium gas. Money spent for parts that can not be used in upgrades and 18% cost of turbo upgrade
2. Have car Dyno tuned and squeeze out the horsepower with stock turbo, hoping I got a good tune so no blow
3. Install larger turbo with conservative tune, catted down pipe. Maybe exhaust system as Bull Run has done.
I know more hp is left on table but as I say before just feel larger turbo will make it all work under less load, not trying to have fastest car

1. If the warranty is not required, I'd go with a pro-tune, which accounts for various mods.
2. Try to have the car dynoed by someone that tunes forced induction cars to reduce chances of ecoboom, although most of ecoboom stories I hear are from folks driving rather normally on the street.
3. Don't go too crazy with the turbo size unless you're upgrading the block soon. I got catted DP for noise and stink control. If those are not important to you, go with the catless DP for less lag and more power. Let your tuner know what kind of conditions you'll be driving in. I told my tuner that I see close to 120 degree ambient temperature during the summer and I have a tune that can handle the heat without issues.

The article below is another good reason why I'm suggesting FBO before doing the turbo upgrade. Boost levels you typically see are measured at the intake manifold and doesn't account for any pressure loss. For example, a car running 20 PSI of boost with inefficient intake track that causes 6 PSI of pressure drop means the turbo has to do 26 PSI of work to provide 20 PSI of boost at the manifold. Same car with upgraded intake track that only has 2 PSI drop means its turbo only has to do 22 PSI of work. While both cars end up with same manifold pressure, the latter car will have lower charge temperature, less prone to knocking, and make more power.

http://stratifiedauto.com/blog/a-technical-discussion-of-intakes-and-turbocharging/

 

[MakStang]

Interested as well. I am planning to fit the PTE NX2 turbo kit if I manage to get it to Europe without all these ridiculous taxes.

Mine is a daily driver too, but I like to know that I have that extra power under the hood. Running on 100 RON fuel (US equivalent is 93). Is the PTE NX2 drop-in a good setup for a daily driver? Is it worth the hassle and the money or would I prefer to go back to the stock turbo after a while?

 

[Regs]

The turbo on the mustang matches the engine. Why they call it a matched pair. You increase the turbo size, you will increase the loads in the upper RPM range. So acceleration might take a little dip for higher engine speed (horse power). You want to pick your target for HP - lets say 360 WHP to play it safe. You want the turbo to be rated for 300-420 HP ballpark for maximum efficiency. Mind you that the valve train in the ecoboost is tuned and made for the volumetric efficiency of the smaller turbo (they can only open for so long and so fast). You also have to assume that the ecoboost can handle the higher engine speeds under certain loads - and only the designers of the engine know that. So even if you tune it, you will be added more stress to the optimal output of the engine. It's all about being realistic.

 

[ElAviator72]

The turbo on the mustang matches the engine. Why they call it a matched pair. You increase the turbo size, you will increase the loads in the upper RPM range. So acceleration might take a little dip for higher engine speed (horse power). You want to pick your target for HP - lets say 360 WHP to play it safe. You want the turbo to be rated for 300-420 HP ballpark for maximum efficiency. Mind you that the valve train in the ecoboost is tuned and made for the volumetric efficiency of the smaller turbo (they can only open for so long and so fast). You also have to assume that the ecoboost can handle the higher engine speeds under certain loads - and only the designers of the engine know that. So even if you tune it, you will be added more stress to the optimal output of the engine. It's all about being realistic.

IIRC, many of the tuners consider 350 HP to be about the safe limit of the engine/block (that's about the limits of what the stock HPFP can fuel the engine with). Anything higher and you have to look at alternative fuels, an auxiliary fuel system, or an aftermarket HPFP...and start taking into consideration if the rods/pistons are strong enough for the job, and if the open deck design of the engine is up to the task or should you go to a closed deck design? (someone makes a closed deck block...).

 

[MakStang]

If the limit of the block is 350hp without using alternative fuel, an auxiliary fuel system, or an aftermarket HPFP, then I wonder if the use of an aftermarket turbo alone, without any other supporting mod, is worth the investment. I mean it's just an extra 33hp from the stock turbo, assuming that you are on pure high quality gas, right?

I would like a better turbo on my car, but I thought that I could reach higher power levels, without the need to add any other mods. I remember reading somewhere that the PTE can reach 390-400 whp on high octane gas, without any risk to the motor and this convinced me to start thinking about investing on this turbo. I have no plans to use alternative fuel, as I have no access to this kind of fuel in my country.

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