Hot Rod Forum : Hotrodders Bulletin Board - Reply to Topic
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine> Saab Turbos on SBC
User Name
Password
lost password?   |   register now

Thread: Saab Turbos on SBC Reply to Thread
Title:
  
Message:
Trackback:
Send Trackbacks to (Separate multiple URLs with spaces) :

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Additional Options
Miscellaneous Options

Topic Review (Newest First)
09-05-2010 01:06 PM
zildjian4life218 The short block is all together. I will be ordering the cam soon hopefully and then I can degree the cam, put the timing cover on, and the oil pan.


For those of you who are observant you probably noticed that piston 1 appears to be in backwards due to the dot on the piston facing the back. It was for the even side but the only piston I had left. I had a pile of pistons from two different 305s. One came apart so most of it was junk. My machinist said the orientation on the pistons doesn't matter for that style heads just the rod orientation does which is correct.
08-30-2010 09:31 AM
zildjian4life218
Quote:
Originally Posted by turbolover
be sure to get the incoming charge as cool as possible. heat soak is a problem with smaller turbos, but isn't a big deal if you cool down the charge.
I will definitely be running an intercooler and possiblly a Meth injection setup
08-30-2010 08:16 AM
turbolover be sure to get the incoming charge as cool as possible. heat soak is a problem with smaller turbos, but isn't a big deal if you cool down the charge.
08-30-2010 08:10 AM
zildjian4life218 Well I went to keith blacks website and used their calc for ring gap. I put the top ring at about .028" and the second ring at .030". The calc said .026" and .028" but i would rather things be on the loose side as opposed to the tight side.
08-19-2010 09:19 PM
zildjian4life218 Anyone any ideas on the ring gap? Stock bore 305. Gonna be running 12-15lbs
08-19-2010 09:08 AM
zildjian4life218 Any idea what I should gap the rings too. I got some enginetech El cheapo rings. Just putting some dished stock pistons back in it. I'm having a hard time believing this is gonna make over 400hp with the t25 turbos. Later ill build a 305 with the forged pistons I got and bigger turbos. I put the top ring in and its sitting at about .020. Thanks for all the help and support.
07-28-2010 08:32 PM
zildjian4life218
Quote:
Originally Posted by TurboS10
Very, very goo grasshoppa....now I show you calcula5tor to do math for you :

http://www.turbofast.com.au/javacalc.html

Now that you understand the math you can plug things in to the above listed calculators and actually understand what you are seeing.

There are some points to consider. First, you are only calculating peak RPM. How much are you going to operate at full power? Second if you run those numbers again for the same boost numbers at 3500RPM and I think you will find that it is about perfect. How much time will you spend around this range? Third, the map does continue and if you continue the lines you can see it will be right at the edge, but will in fact still feed the engine sufficiently.

My point in all of this is if it is a street car, it will work very nicely and spool instantly which will make for a very fun ride.

I also dont disagree that they are a little bit small, but not much.....in the end it comes down to what you are wanting to do.
Thanks for the link. I made an excel chart with the same idea as the above link just not written in java script. where on one side you put in the constants and it outputs on the right. Oh well at least i now know what the formulas do. Thanks for all your help everyone. I am waiting to get sometime so i can go down and bore my block. The forged pistons my machinist gave me are .030 or .040 over so gotta punch out the block.
07-25-2010 09:42 PM
TurboS10 Very, very goo grasshoppa....now I show you calcula5tor to do math for you :

http://www.turbofast.com.au/javacalc.html

Now that you understand the math you can plug things in to the above listed calculators and actually understand what you are seeing.

There are some points to consider. First, you are only calculating peak RPM. How much are you going to operate at full power? Second if you run those numbers again for the same boost numbers at 3500RPM and I think you will find that it is about perfect. How much time will you spend around this range? Third, the map does continue and if you continue the lines you can see it will be right at the edge, but will in fact still feed the engine sufficiently.

My point in all of this is if it is a street car, it will work very nicely and spool instantly which will make for a very fun ride.

I also dont disagree that they are a little bit small, but not much.....in the end it comes down to what you are wanting to do.
07-24-2010 10:13 PM
zildjian4life218 So I think I might go with some bigger turbos...........

Can someone with turbo knowledge or any knowledge that can help check my math. I bought a book titled "Street Turbocharging" by HP Books. In here is a step by step calculations for plotting turbo compressor maps.

Okay first off you figure out the specs of the engine
305ci
assuming 80% VE
8.5:1 CR
12psi
Redline 5000
IC Eff 60%

Figure out the Pressure Ratio of the compressor
(12+14.7)/14.7 = 1.816

Then the Pressure Ratio of the System assuming a 1 psi drop through the Intercooler
(12-1+14.7)/14.7 = 1.748

Now we figure out the temperature rise after the compressor assuming ideal
Toutideal = [(Tin+460)*PR^0.283]-460
[(85+460)*1.1839]-460]
185*F

Now we find the actual temperature assuming the efficiency of the turbocharger which is 72%.
Toutactual=[(185-85)/.072]+85 = 223.8*F

Now we find the temp of the air coming out of the Intercooler.
TempIC=224-[.60*(224-85)]
140.6*F

The Density Ratio is then figured out by
DR = 1.75*[(85+460)/(140.6+460)] = 1.5869

Then you figure out the VFR which is the volumetric flow rate at redline of the NA engine.
VFR=305*5000*.80/3456= 353cfm

Last step is to find the Mass flow rate which is
MFR=(2.703*14.7*353*1.5869)/85+460 = 41 lb/min

Sorry its so long I want to make sure I have this somewhat right. Thanks! These turbos flow 15 lb/min at a PR of 1.82 so idk if they will quite cut it. I think I will be spinning them way too much and burn them up.

I attached a compressor map for the turbo I am using. The red dot shows where I would be sitting.
07-14-2010 10:41 AM
zildjian4life218
Quote:
Originally Posted by TurboS10
Yes, if you are adding resistors then you are correct. Some ECU's can be set to work with lowZ without the resistors, but some require them. Depends on your end setup.
it will be a megasquirt ms2.
07-14-2010 10:09 AM
TurboS10
Quote:
Originally Posted by zildjian4life218
Alright thanks im gonna go through tonight and play with them and see if it works or not. Ill also post pictures of both injectors. I believe they are low impedance because when my friends use them on their hondas they have me wire in a resistor box that is used to drain off the excess current. Which would make me to believe that the factory injectors are high impedance.
Yes, if you are adding resistors then you are correct. Some ECU's can be set to work with lowZ without the resistors, but some require them. Depends on your end setup.
07-14-2010 08:58 AM
zildjian4life218
Quote:
Originally Posted by TurboS10
Either they will fit or they will not. There is no room in between. You will need to know if they are high or low impedence as well.
Alright thanks im gonna go through tonight and play with them and see if it works or not. Ill also post pictures of both injectors. I believe they are low impedance because when my friends use them on their hondas they have me wire in a resistor box that is used to drain off the excess current. Which would make me to believe that the factory injectors are high impedance.
07-13-2010 09:40 PM
TurboS10 Either they will fit or they will not. There is no room in between. You will need to know if they are high or low impedence as well.
07-13-2010 03:30 PM
zildjian4life218 I was talking the other day with some friends of mine that are big into turbo charging hondas. They said for injectors the can get a hold of 4 450cc injectors for $50 off of a DSM factory turbo car. Anyway these would work on my tpi intake? I used an online calc and found them to be 42 lb/hr which would be perfect for my build. I was wondering what I would have to worry about fitting properly. I know for the wiring connector I can just get the connectors from that car and splice them onto my harness. Not sure on the intake rail connection or where they go into the intake. Any one have any idea?
07-04-2010 07:24 AM
zildjian4life218





Soon ill pull the turbo apart to clean it up. Just waiting for some time. I also have to go back to the yard to get another one.
This thread has more than 15 replies. Click here to review the whole thread.

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT -6. The time now is 08:29 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.