Turbo selection for my engine
09-24-2010, 10:29 PM
#1
0.0 BAR
Thread Starter
Join Date: Sep 2010
Posts: 6
Turbo selection for my engine
OK I will give you some info
Its is a 470 bbc , burns e85,quickfuel carb solid roller valve train, dome pistons and 11.5-1 compression , msd 6A ignition on gutted hei. I run a final timing of 34deg. The engine make 525hp at the flywheel.
I have headers with t4 flanges on them. I want to put turbos on it.
From what I understand about forced air the cr raises with every pound of boost, so I will have to get some forget dished pistons to get my cr to about 8.50-1. I want to keep this motor streetable and my cruising rpm is 2200. I was looking at turbos on ebay
TO4E the item # 170535547007. Would two of them be big enough. I dont want the turbos to start working at 5000rpm. Am I mistakin to want them to start coming on at about 2500rpm, or so.
I will be switching to a mpfi from affordable fi. It supports turbos in the programming. That should make it a little easier on me.
This is where im at right now. Am I headed the right way any and all help is greatly appreciated.
Its is a 470 bbc , burns e85,quickfuel carb solid roller valve train, dome pistons and 11.5-1 compression , msd 6A ignition on gutted hei. I run a final timing of 34deg. The engine make 525hp at the flywheel.
I have headers with t4 flanges on them. I want to put turbos on it.
From what I understand about forced air the cr raises with every pound of boost, so I will have to get some forget dished pistons to get my cr to about 8.50-1. I want to keep this motor streetable and my cruising rpm is 2200. I was looking at turbos on ebay
TO4E the item # 170535547007. Would two of them be big enough. I dont want the turbos to start working at 5000rpm. Am I mistakin to want them to start coming on at about 2500rpm, or so.
I will be switching to a mpfi from affordable fi. It supports turbos in the programming. That should make it a little easier on me.
This is where im at right now. Am I headed the right way any and all help is greatly appreciated.
09-24-2010, 11:59 PM
#2
0.5 BAR
Join Date: Mar 2009
Posts: 77
this is untrue. BBC can take more boost.
i know a few guys running 11:1 pistons with a supercharger and no issues whatsoever.
dont follow the 4banger rule with a BBC. the motors can take MUCH more. believe me.
also, with a BBC it requires alot more air. so a small TD04 wont be enough. you will max out a small T25 or T28 stupidly fast. look for a bigger turbo. 10PSI on a T25 is not the same as 10PSI on a T28.
i know a few guys running 11:1 pistons with a supercharger and no issues whatsoever.
dont follow the 4banger rule with a BBC. the motors can take MUCH more. believe me.
also, with a BBC it requires alot more air. so a small TD04 wont be enough. you will max out a small T25 or T28 stupidly fast. look for a bigger turbo. 10PSI on a T25 is not the same as 10PSI on a T28.
09-26-2010, 10:42 PM
#6
0.0 BAR
Thread Starter
Join Date: Sep 2010
Posts: 6
Ok thanks now what numbers should I be looking for in the gt45's I see all these specs and I have no knowledge of turbocharging. The ones im looking at are
Compressor: Inlet = 4 3/16", Inducer = 68.7MM, Exducer = 97.8 MM, Trim = 69, A/R = 0.66, Intake (ID / OD) = 2.25" / 3.25"
Turbine: Outlet = 4", Turbo flange = T4, Downpipe flange = 3.5" V-band, Inducer = 87.4 MM, Exducer = 77 MM,Trim = 92, A/R = 1.05
These are huge compared to alot of what i seen online. I really need these??
Compressor: Inlet = 4 3/16", Inducer = 68.7MM, Exducer = 97.8 MM, Trim = 69, A/R = 0.66, Intake (ID / OD) = 2.25" / 3.25"
Turbine: Outlet = 4", Turbo flange = T4, Downpipe flange = 3.5" V-band, Inducer = 87.4 MM, Exducer = 77 MM,Trim = 92, A/R = 1.05
These are huge compared to alot of what i seen online. I really need these??
Thread
Thread Starter
Forum
Replies
Last Post
mpmarino
Forced Induction
26
11-16-2011 10:24 AM
EdgeminSH
Forced Induction
15
01-27-2004 10:38 PM
