Twin Turbo vs. Single Turbo V6: A Dissertation

tower74

So the heat issues with the two turbos being that close to, well everything doesn't effect anything? No extreme turbo temps? I thought heat was the enemy for FI? I know when it was warm out the car runs normal, but when it's cold I could tell the diffrence in power. Just wondering.

djpathfinder

Thanks for the write-up Mike! A lot of great info in there, including references to the WRX/STi, another vehicle that we own, and now better understand. Repped!

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2012 GT-R Black Edition Jet Black
2010 370Z 40th Anniversary // SOLD

Kingbaby

I posted this on my club's facebook page.

For those that fall asleep in class!

How a turbo works - YouTube

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blackonorange

So heat is good ? This is like a big advertisement the thread is single vs twin and the post fails to recognize the advantages of single. Maybe I'm biased. And cell hop off the test pipe you've made your point. Good info tho GTM

theaudir8fan

This is a great post by Mike, credit given to GTM in all the R&D they do on their kit, it is very well engineered, and they really know the technicalities when being questioned.

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2007 Infiniti G35S 5AT PG; GTM; KW; Hotchkis; Stillen; Berks; SPC; GT-spec; SxExCx

JayzTang

Love this article.

Heat is good when it is in the combustion chamber. Once it transfers to other area, not so much. Remember we have yet to use them 100% of the power from gasoline. Gasoline engine is only 18 to 20% efficient in terms of using the energy from gasoline. The 80% left is part of what comes out of the exhaust - Heat. Turbo is a device to reuse this wasted energy. There is a reason as to why turbos are usually put closest to the engine as possible.

Given the same horsepower goal without budget on the same motor, twins will still top single just because it will always spool quicker for better turbo response. But this is unrealistic because every build has a budget.

Given a realistic budget on the same motor for FI, single turbo usually would be better to hit higher horsepower because 2 turbos with 2 sets of piping will always out-cost 1 turbo with 1 set of piping, plus you do not .

SharpByCoop

Hi Mike,

Thank you for your education. I learned quite a bit here, and I'm no rooky. Some of the points and parts of my GTM kit make more sense to me (Cast manifolds seemed like a shortcoming. Not.)

I learned specifically about single vs. twin turbos, but learned some 'basics' which apply to all FI models.

Not only was this information concise and correct, you write in a manner which allows us to clearly understand. That's a gift in itself. (From one who also writes to clarify often. )

I'm printing this out to hand out to others.... Again, thank you.

Coop

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Jim Cooper - (Retired: '08 Infiniti G37 Sport • TheShopCT built • 11.13 @ 123 mph (click for vid) • GTM Stage II Twin Turbo • 5-speed A/T Level Ten built • 591whp @17 lbs boost)

JB-370z

Lots of good info. You are valuable to this forum Mike, thank you.

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ll Baker Tuning ll GTM ll Powerhouse Amuse ll HKS ll Up-Rev ll iForged ll AP Racing ll Pioneer ll SPL ll Bride ll Top Secret ll OS Giken ll
GTM Stage 2 Twin Turboed 370z (First in Texas, Thanks To Baker Tuning)

blackonorange

Our cars don't have equal length headers? :s

Nixlimited

Nice writeup Mike.

Someone mentioned they thought heat was bad because their car ran better in cooler weather. The car runs better in cool weather because the engine produces power by the change in pressure caused by heating air in the combustion chamber (PV = nRT). Accordingly, if the air starts off colder at the intake (e.g. when it is cool outside) then the temperature delta after combustion can be greater and more power can be made. With that said, you want the combustion to be as hot as possible to create as much P as possible, but you have to keep material science in mind. Simply put, the metals used to make automobile engines can only take so much heat before they degrade and break. The waste heat is very useful for the turbos, as Mike mentioned. It's really just a matter of controlling the heat and making it do your bidding.

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blackonorange

This engine na already puts the car in limp lode when pushing it why would we want to push it even more?

Cell

There are other cars out there that have over heating oil issues when being pushed too. It is just that our cars come with a gauge that shows the temp. If we never had the gauge people wouldn't even think about it till they put a gauge in. This is why we have the option to add oil coolers.

Red__Zed

lolwat?


if you have no gauge and limp mode, you'll know because of limp mode

if you have no gauge and no limp mode, you'll know because people would be blowing their engines at the track.

Cell

Yes we will know because of limp mode and people blowing up their engines at the track, but how many people actually goes to the track? I've heard stories of other cars going into limp mode and having engine failure because of high oil temps. Our cars are not the only ones with that problem. That's what I was trying to point out.

The oil temp issue is blown way out of hand in our community because we have a gauge. Don't misunderstand me though, it is still a problem especially for track use.

Nixlimited

I never suggested that. I was talking general principles of engine function, and I think you missed that whole point. If you can't control the heat (e.g. 370Z in some conditions), it's a problem. If you can, the more the merrier. Pressure created through combustion is proportional to temperature increase during combustion. It's very simple.

__________________
Car Sold! Pleasure being a part of the Z community.
New ride: 2015 GT-R - 647 WHP / 641 WTQ (e85) & 543 WHP / 519 WTQ (91)