New Project - Introducing the boards soon to be first roots blown 3.4 v6
#51
Supreme Member
Thread Starter
iTrader: (1)
Join Date: Apr 2008
Location: Utah
Posts: 10,401
Likes: 0
Received 2 Likes
on
2 Posts
Car: 89 RS 89 iroc 87 firebird
Engine: 3.1 Turbo/ 355 twin turbo
Transmission: a4 w/ 4500 stall/ a4 / t5
Axle/Gears: strange s60 /w 3:42's
Re: New Project - Introducing the boards soon to be first roots blown 3.4 v6
#52
Member
Re: New Project - Introducing the boards soon to be first roots blown 3.4 v6
You sir, are a provider of top quality entertainment. I love it!
#53
TGO Supporter/Moderator
iTrader: (12)
Join Date: Jul 1999
Location: SALEM, NH
Posts: 11,724
Likes: 0
Received 89 Likes
on
75 Posts
Car: '88 Formula, '94 Corvette, '95 Bird
Engine: LC9, 355" LT1, LT1
Transmission: T5, Zf6, 4L60E
Axle/Gears: 3.42, Dana44 3.45, 3.23
Re: New Project - Introducing the boards soon to be first roots blown 3.4 v6
Umm. What ??
Boost is a measurement of restriction. On the same complete engine, 20 psi of boost would represent the same airflow regardless of compressor.
Now if you said, 20 psi on my briggs n stratton riding mower, and 20 psi on a 540 cubic inch big block are not the same thing, you would be correct.
-- Joe
Boost is a measurement of restriction. On the same complete engine, 20 psi of boost would represent the same airflow regardless of compressor.
Now if you said, 20 psi on my briggs n stratton riding mower, and 20 psi on a 540 cubic inch big block are not the same thing, you would be correct.
-- Joe
#54
Supreme Member
Thread Starter
iTrader: (1)
Join Date: Apr 2008
Location: Utah
Posts: 10,401
Likes: 0
Received 2 Likes
on
2 Posts
Car: 89 RS 89 iroc 87 firebird
Engine: 3.1 Turbo/ 355 twin turbo
Transmission: a4 w/ 4500 stall/ a4 / t5
Axle/Gears: strange s60 /w 3:42's
Re: New Project - Introducing the boards soon to be first roots blown 3.4 v6
Umm. What ??
Boost is a measurement of restriction. On the same complete engine, 20 psi of boost would represent the same airflow regardless of compressor.
Now if you said, 20 psi on my briggs n stratton riding mower, and 20 psi on a 540 cubic inch big block are not the same thing, you would be correct.
-- Joe
Boost is a measurement of restriction. On the same complete engine, 20 psi of boost would represent the same airflow regardless of compressor.
Now if you said, 20 psi on my briggs n stratton riding mower, and 20 psi on a 540 cubic inch big block are not the same thing, you would be correct.
-- Joe
a t3 turbo at 20 psi is only going ot move about 25 lbs of air on a 2.8 that will make about 250 hp @ 20 psi
strap a gt3582 on a 2.8 and its going to make about 300 hp at 12 psi
#55
Supreme Member
iTrader: (2)
Join Date: Mar 2011
Location: Northwest Ohio
Posts: 6,273
Likes: 0
Received 23 Likes
on
18 Posts
Car: 1991 Camaro RS
Engine: BBC 509 Merlin ii 9.6:1 pump gas
Transmission: ATI pro th350 sfi case. TSI 5500 st
Axle/Gears: Strange S60 4:10s
Re: New Project - Introducing the boards soon to be first roots blown 3.4 v6
I can attest to the above.
PSI is just restriction, not cfm or lbs/min flow.
PSI is just restriction, not cfm or lbs/min flow.
#56
Supreme Member
Join Date: Jan 2011
Location: Lynden WA
Posts: 1,929
Likes: 0
Received 8 Likes
on
7 Posts
Car: 84 Trans Am, 84 Fiero, 86 944
Engine: 5.0, 2.5, 2.5
Transmission: 5spd
Re: New Project - Introducing the boards soon to be first roots blown 3.4 v6
idk if it was ever covered, but what was you main goal of this build besides having a badass looking 3.4? was there a power goal?
#57
Supreme Member
Thread Starter
iTrader: (1)
Join Date: Apr 2008
Location: Utah
Posts: 10,401
Likes: 0
Received 2 Likes
on
2 Posts
Car: 89 RS 89 iroc 87 firebird
Engine: 3.1 Turbo/ 355 twin turbo
Transmission: a4 w/ 4500 stall/ a4 / t5
Axle/Gears: strange s60 /w 3:42's
Re: New Project - Introducing the boards soon to be first roots blown 3.4 v6
gee that'd be great if what little money i had wasn't going toward my planned 4.3 turbo swap done alot of reading, but i'm a total newb to tuning and turbos, and so far all i've got is my blown up (nearly) z28, everything else i'll need remains to be bought.
idk if it was ever covered, but what was you main goal of this build besides having a badass looking 3.4? was there a power goal?
idk if it was ever covered, but what was you main goal of this build besides having a badass looking 3.4? was there a power goal?
#58
Supreme Member
Join Date: Jan 2011
Location: Lynden WA
Posts: 1,929
Likes: 0
Received 8 Likes
on
7 Posts
Car: 84 Trans Am, 84 Fiero, 86 944
Engine: 5.0, 2.5, 2.5
Transmission: 5spd
Re: New Project - Introducing the boards soon to be first roots blown 3.4 v6
i support hot rodders doing things just to do them, unless its a 350 swap (too common) or an ls swap (becoming way too common) they're just so boring to read through
#59
TGO Supporter/Moderator
iTrader: (12)
Join Date: Jul 1999
Location: SALEM, NH
Posts: 11,724
Likes: 0
Received 89 Likes
on
75 Posts
Car: '88 Formula, '94 Corvette, '95 Bird
Engine: LC9, 355" LT1, LT1
Transmission: T5, Zf6, 4L60E
Axle/Gears: 3.42, Dana44 3.45, 3.23
Re: New Project - Introducing the boards soon to be first roots blown 3.4 v6
Turbos are not rated in boost.
A Turbo with 20psi of manifold pressure on any given motor tells absolutely nothing other than the fact that it's forcing air into the motor.
-- Joe
#60
Supreme Member
iTrader: (16)
Re: New Project - Introducing the boards soon to be first roots blown 3.4 v6
Originally Posted by anesthes
Turbos don't make boost, they move CFM.
#61
TGO Supporter/Moderator
iTrader: (12)
Join Date: Jul 1999
Location: SALEM, NH
Posts: 11,724
Likes: 0
Received 89 Likes
on
75 Posts
Car: '88 Formula, '94 Corvette, '95 Bird
Engine: LC9, 355" LT1, LT1
Transmission: T5, Zf6, 4L60E
Axle/Gears: 3.42, Dana44 3.45, 3.23
Re: New Project - Introducing the boards soon to be first roots blown 3.4 v6
Bingo. Resistance is resistance, what matters is the amount of cfm being applied after that resistance reading. If we use two boost gauges at the same time to understand this, one measuring resistance in the plenum the more common way, and another measuring resistance just before the individual intake valve, they will give two different resistance readings. This is why 20-psi in the plenum from two different turbo's is essentially the same measure, it is meaningless, and the reason why it is meaningless is because it only tells half of the story. The better turbo moving more cfm will "follow through" after that first 20-psi resistance reading and will force just as much resistance on the second gauge nearest the intake valve, while the slower turbo will slow down after that first 20-psi resistance reading, and isn't really applying as much. This is why ebay turbo's are a lot cheaper than Turbonetic turbo's...
Besides, the phenomena you're speaking of isn't as common with short runner, single plane intakes with a large cross sectional area in the runner.
On something like a tuned port intake, say you saw 20psi in the plenum, you might see a little pressure drop in the actual intake runner of the head.
And even still, I don't see how the larger compressor could result in a higher resistance measurement at the valve without increasing the measured pressure in the plenum. I'd love to see a flow modeled in software to show it.
Besides, I doubt that is what they were talking about.. A good percentage of people on this forum, and even the industry seem to rate head units (and pulleys when talking blowers) in 'PSI' as if it was a meaningful comparison.
-- Joe
#62
Supreme Member
iTrader: (16)
Re: New Project - Introducing the boards soon to be first roots blown 3.4 v6
Originally Posted by anesthes
That is a good point, but I would be more concerned with the adiabatic efficiency of the compressor...
#63
TGO Supporter/Moderator
iTrader: (12)
Join Date: Jul 1999
Location: SALEM, NH
Posts: 11,724
Likes: 0
Received 89 Likes
on
75 Posts
Car: '88 Formula, '94 Corvette, '95 Bird
Engine: LC9, 355" LT1, LT1
Transmission: T5, Zf6, 4L60E
Axle/Gears: 3.42, Dana44 3.45, 3.23
Re: New Project - Introducing the boards soon to be first roots blown 3.4 v6
Bingo again, we want the highest efficiency possible. The boost gauge simply measures resistance, but it has no way of measuring usable cfm. We measure this by dividing the amount of power that goes into building pressure by the total power put into the compressor. An ebay turbo, and an Turbonetics turbo, at the same turbine and compressor size, can both be measured at 15-psi of boost pressure in the plenum, but what determines usable cfm is the efficiency of the pressurized air, as some turbo's, like ebay turbo's, although can achieve high boost resistance readings, are only more efficient at heating up the air charge, reducing power, and leaving a lot on the table...
But I still don't see how a higher flowing (more CFM) compressor will have a proportionate gain in pressure at the valve, without increasing pressure in the plenum.
Keep in mind 99.9% of the efficiency of a compressor is the impeller, and folks on ebay having been making replacement impellers that are much better than OE for quite some time now. I don't know if it's getting cheaper to machine helical impellers or what.
-- Joe
#64
Re: New Project - Introducing the boards soon to be first roots blown 3.4 v6
We're in total agreement of that. If your outlet temperature is 300 degrees on one, and 120 on the other obviously the later will make more power (and not blow up).
But I still don't see how a higher flowing (more CFM) compressor will have a proportionate gain in pressure at the valve, without increasing pressure in the plenum.
Keep in mind 99.9% of the efficiency of a compressor is the impeller, and folks on ebay having been making replacement impellers that are much better than OE for quite some time now. I don't know if it's getting cheaper to machine helical impellers or what.
-- Joe
But I still don't see how a higher flowing (more CFM) compressor will have a proportionate gain in pressure at the valve, without increasing pressure in the plenum.
Keep in mind 99.9% of the efficiency of a compressor is the impeller, and folks on ebay having been making replacement impellers that are much better than OE for quite some time now. I don't know if it's getting cheaper to machine helical impellers or what.
-- Joe
Besides that, the pulleys being rated in "PSI" is probably a lot like converters IMO. By that I mean they say "this is a typical stock engine, you put this setup on it and then run this pulley you'll get around this boost level. No, it's not accurate if you're not running the same configuration as they were but it's designed to be a rough baseline. Much like advertised duration or converter stall it's likely more useful within a single line of products to reference one to another (e.g. I need an 8 PSI pulley this 6 PSI one doesn't produce the desired amount of boost due to my heads being ported.)
#65
Supreme Member
iTrader: (1)
Join Date: Oct 2005
Location: Glen Park, NY
Posts: 1,050
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1987 IROC-Z
Engine: TPIS II Supercharged w/Nitrous
Transmission: 700R4 Probuilt
Axle/Gears: 3:73 Richmond 12 Bolt
Re: New Project - Introducing the boards soon to be first roots blown 3.4 v6
Thread
Thread Starter
Forum
Replies
Last Post
LT1Formula
Engine/Drivetrain/Suspension Parts for Sale
7
10-08-2015 08:34 PM
Linson
Auto Detailing and Appearance
12
10-01-2015 09:50 PM