American Revolution

iTrader: (4)

Ok so if I do end up going twins what size should o be looking for and what brand?

American Revolution

iTrader: (4)

So if I do end up going twins what brand and size should I go with in my engine set up

gsteele

"Choosing between a single or parallel twin turbo setup is primarily based on packaging constraints in the engine bay, or a personal choice by the tuner. In most cases, for top performance, a single turbo is preferable because larger turbos are generally more efficient than smaller turbos. However, often there is not room for one large single, or the tuner wants the visual impact of twin turbos."

https://www.turbobygarrett.com/turbo...between_turbos

oscs

iTrader: (19)

His original comment is such a vague statement and part of the reason i laughed in the first place. Also you cant ignore the all important "Generally" thrown in there by garrett. There is so much more to this. Yes of comparable turbine sizes Twins are less efficient but again that detailed information was not applied. In this application the OP is not taking his original turbo size and then splitting the difference into two smaller turbos... That's the only way the argument makes sense. In which no one does. There is a threshold. Hell you could read that as "one big turbo is more efficient than 2 smaller turbos" or you could read it exactly as its stated "larger turbos are more efficient than smaller turbos" which completely debunks the argument.

There is a reason the fastest turbo race cars in the world run twins and not a big single and i'm quite sure its not "packaging constraints" But.. That's just my opinion.

gsteele

^^ All good points. I always wish that Garrett had been more specific and given their parameters when making that statement. It would be interesting to know under which conditions exactly they would recommend a single over twins for "top" performance. We may even disagree with them about what "top" performance means.

oscs

iTrader: (19)

Agreed

1CAMWNDR

iTrader: (21)

If it were me I would put a billet S480 and turn it to about 25 psi.....

American Revolution

iTrader: (4)

[QUOTE=1CAMWNDR;19371749]If it were me I would put a billet S480 and turn it to about 25 psi.....[/QUOTE


That's what I thinknima end up doing just staying how I am and get the BW
Maybe will go twins when I finish my 408motor later

kingtal0n

iTrader: (1)

twins. always twins if you have the space.

most successful plans in nature are twins... hands, eyes, brain, diploid is the way to be !

redss82

why not talk to the guys over at forced inductions and see if they can shove something nasty in your gt4788 housing if its not shot

gtfoxy

S480 or a 588 if you want even more, providing the base volumetric efficiency is there.

American Revolution

iTrader: (4)

That's what I am leaning towards rite knaw.

American Revolution

iTrader: (4)

I did call them and talked to them but asked them and all they told me is that I need to send the turbo in and so they can see what they can do

American Revolution

iTrader: (4)

Looking into them at this moment

1CAMWNDR

iTrader: (21)

A 5 Series isn't really needed. Especially on the small more limitations the op currently has. Even an S480 would like a 4"+ bore and bigger heads/valves than you can put on the LS1 bore motor.

rotary1307cc

iTrader: (5)

Why would you use a 500 over a gt55 based unit. Makes no sense

American Revolution

iTrader: (4)

So u think the s480 is a good choice and with that turbo would I have room to grow into it?

1CAMWNDR

iTrader: (21)

A billet S480 with the correct turbine side for your engine will make all the power you could dream of in a small bore 383. Then throw it on your bigger bore 408 and let it breathe. Might consider a turbine side change with the 408.....but it will damn sure work. Depending on cam/heads/rpm/tune you can make 1000whp+ with a 408 and a billet S480.

Talk to Forced Inductions about what it can do with your current 383 and future 408 and if they recommend different turbine wheels or housings.

oscs

iTrader: (19)

This is good advice

aaronware76

iTrader: (2)

Have you talked to Casey at Huron Speed? Super helpful with getting you set up to meet or exceed your goal. My buddy has their twin kit with 2 precision 66mm turbos and he hit well over 1200 rwhp at about 24 lbs and there is still room to turn it up. This is on a Thompson Motorsports forged 370 ls motor he got through Huron Speed. I've got their single turbo kit that retains ac going on my car right now. I'll be running a turbonetics 78/75. All is going really well with the install. Should make over 600 on low boost with some meth. Bottom line...Casey can hook you up completely at a great price with lots of help before and after the sale. This is from personal experience on two builds. His email is casey@huronspeed.com.