turbo sizing
09-05-2011, 05:56 PM
#1
Junior Member
Thread Starter
Join Date: Jun 2011
Posts: 80
Likes: 0
Received 0 Likes
on
0 Posts
Car: 89' Bandit 2 #104 of 500
Engine: LS1 5.7L
Transmission: 4L60e
Axle/Gears: 3.23 posi
turbo sizing
i have a 89 firebird that i am in the process of making a street/road race monster that will be almost a daily driven vehical.
i have sfc,stut and sway bars done and koni yellows already in shipping process, goodyear f1 asymmetric 2 tires, lt1 and t56 tranny in garage ready to be swapped in but i didnt want to start that yet untill i know what turbo system or custom i wanna go with. i plan on having a smaller quick spooling turbo.
please any suggestions will be greatly needed and used!! first time with the muscle car world wanna do it right i also own a 05 sti stage 2 12.1 1/4mile but making that thing a beast was very simple new age tech and 4 wheel drive makes life simple...
i have sfc,stut and sway bars done and koni yellows already in shipping process, goodyear f1 asymmetric 2 tires, lt1 and t56 tranny in garage ready to be swapped in but i didnt want to start that yet untill i know what turbo system or custom i wanna go with. i plan on having a smaller quick spooling turbo.
please any suggestions will be greatly needed and used!! first time with the muscle car world wanna do it right i also own a 05 sti stage 2 12.1 1/4mile but making that thing a beast was very simple new age tech and 4 wheel drive makes life simple...
09-06-2011, 07:37 AM
#2
Junior Member
Join Date: May 2011
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
Re: turbo sizing
You should check out our turbo recommendations calculator
On the results page it will give you a range of aspect ratios for your turbine based both on your redline and on your peak boost ... something like 0.48 to 0.63 A/R (the actual numbers will vary depending on what your specific engine calculation is)
For a faster spooling street turbo at lower boost levels go for an smaller aspect ratio turbine (closer to 0.48 A/R) in this example and that will give your exhaust air more of a direct nozzle effect of air stream on the outer edge of the turbine blades which promotes their acceleration and spool (at the expense of peak flow on the top end which you won't need if all you're running is conservative boost for the street).
Also, when you get to the list of recommended turbos in our calculator you can click on each turbo and get your engine demand line plotted on the compressor map. Choose a turbo that is just large enough to cover your desired power demand.
The smallest sized turbo (with the smallest compressor wheel and lightest center cartridge) that still meets your power goals will give the fastest spool generally.
Finally you have bearing choice... ball bearing turbos have less friction allowing them to accelerate faster hence the faster spool.
So all three factors:
Compressor size
Right Turbine Aspect Ratio
Best choice of available bearings (180* lubrication , 270* , 360* , ball bearing)
All three combined will help your spool
On the results page it will give you a range of aspect ratios for your turbine based both on your redline and on your peak boost ... something like 0.48 to 0.63 A/R (the actual numbers will vary depending on what your specific engine calculation is)
For a faster spooling street turbo at lower boost levels go for an smaller aspect ratio turbine (closer to 0.48 A/R) in this example and that will give your exhaust air more of a direct nozzle effect of air stream on the outer edge of the turbine blades which promotes their acceleration and spool (at the expense of peak flow on the top end which you won't need if all you're running is conservative boost for the street).
Also, when you get to the list of recommended turbos in our calculator you can click on each turbo and get your engine demand line plotted on the compressor map. Choose a turbo that is just large enough to cover your desired power demand.
The smallest sized turbo (with the smallest compressor wheel and lightest center cartridge) that still meets your power goals will give the fastest spool generally.
Finally you have bearing choice... ball bearing turbos have less friction allowing them to accelerate faster hence the faster spool.
So all three factors:
Compressor size
Right Turbine Aspect Ratio
Best choice of available bearings (180* lubrication , 270* , 360* , ball bearing)
All three combined will help your spool
Thread
Thread Starter
Forum
Replies
Last Post