[BostonPerformance]

I read a while back that they make trucks with twin sequential turbos, one that provides low end power and one that provides high in power.
Why doesn't anyone do this in a mustang? I was reading a thread about when going f/i, you gotta balance/choose between low end tq and high end hp..why not do it like the trucks?

[WLJohnson05]

when people do TT that is usually what is done. parallel TT is often extremely hard to tune, from what i understand

[707Stang]

Originally Posted by El33tist I read a while back that they make trucks with twin sequential turbos, one that provides low end power and one that provides high in power. Why doesn't anyone do this in a mustang? I was reading a thread about when going f/i, you gotta balance/choose between low end tq and high end hp..why not do it like the trucks?

ya i believe the new ford S/D Diesels have that set up. and ima have to go with Mr.Jonson, on the tune, but a friend of mine did have it on his rx7

[BostonPerformance]

If I ever go f/i, that's what I'm gonna do. seems like the best way to go

[spdfrek]

I could be wrong but I'm pretty sure the ford super duty is a compound turbo setup, not a sequential. And I haven't seen any kits for mustangs yet that run compound or sequential setups. The last generation rx7 did indeed have a factory sequential setup.

[04mustang232]

i imagine that if was that big of a advantage, someone would have done it. The reason they do it in the superduty and other larger trucks are because they weigh ALOT and their turbo lag is insane, especially when you start really adding boost. How long is turbo lag in a mustang with a decent size turbo? Not that bad from the vids i have seen. It wouldnt be worth all that extra trouble to save yourself from .5 secs of lag. That is, unless your running a 88+ turbo that you have to have a 2.5 reaction time because your sitting there floored trying to spool up a damn 727 turbine. Most people just use a 100 shot sitting on the line getting their cars to rev to the launch RPM.

[Racinjason81]

they dont use compound turbos on mustangs cause they are likely to blow the engines since those setups are high pressure and not meant for gasoline engines,it may work on a high dollar race engine but a single or conventional twin setup is much more effective
and proven.

[TurboLX]

Compound setup's are pointless on anything that's NOT diesel.

When people do twin turbo setup's on a car it's alway's the same size turbo's and spools faster to make the big power fast unlike a big turbo which starts slow but when it spools it hits hard.

[klean4.6]

With recent advancements in turbocharger design, sequential twin turbo systems have fallen out of favor because they are seen as unnecessarily costly and complex.

But sequential twin-turbocharger systems do provide a way to decrease turbo lag without compromising ultimate boost output and engine power

Don't forget about 1993-1998 Toyota Supra Sequential Turbo (JZA8x).

[Racinjason81]

when they crank up the horsepower on those supras they shitcan those sequentials and install a large single dont they.Sequential turbos+gasoline engine=waste of time and money

[spdfrek]

Parallel twins are what many people run, two turbos of matched size, though they aren't always used to spool faster then a big single. Sometimes it a matter of more air then a single can reasonably do.

Sequential twins are designed to spool small then large, and the small will I believe be bypassed when the larger turbo spools, so quick spooling and good top end as well, but needs well matched turbos and more time to design correct then a parallel or compound setup.

Compounds are for higher pressure applications, one turbo feeds pressurized air into the next which again, pressurizes it more. I believe this is done with matched turbos as well as different sizes. Most of what I've seen is different sizes and in diesel applications. Your talking about guys running 45psi-110psi of boost.

I really don't think a sequential setup is a complete waste of time and money on a gas motor, considering the amount of money people put elsewhere, having a turbo setup that could spool fast and still provide top end would just take some time and money to build. For a drag car I wouldn't see a benefit. But why not on a street car? My previous car had reached its torque peak by 2100rpm and was flat up till the 5500-6k range. this was small twins. A proper sequential setup should be able to spool as fast or slightly faster and pull longer.

[Racinjason81]

thats exactly why they went with variable vane turbos which can effectively do the same thing without the restriction which the smaller turbo becomes in the sequential setup.you could get the same effect from by blocking off half of the exhaust side on a larger than normal turbo with a divided exhaust side.another possibility on a divided
exhaust is blocking off one side with a plate on a shaft like a throttle blade that could be activated electronically.similar to the VVT but on the exhaust side. this is what you should invest time and money into because it would be much more effective on a gasoline engine since it would make a large turbo spool like a turbo half its size and not be a restriction when you open up the blade onthe other side of the exhaust

[ImpulseCars]

sequential turbos were useful and have their strengths and weaknesses. But trying to go sequential as an aftermarket modification is difficult because of tuning requirements. Besides, the value of sequential turbos has been diminished by advances in turbo design which have made large turbos like a gt35 dual ball bearing spool just slight slower then a sequential set up on, say a supra, but deliver much more power.