The banner above is an advertisment - if it asks you to download software, please ignore.
Site News -
7/1: Members: Log In to See Fewer Ads! |
5/28: SAAB Evolutions/TSN T-Shirts $14
[General |
Members |
C900 |
9000 |
NG900 & OG93 |
93 |
95 |
NG95 |
99 |
Sonett |
Vintage Models |
Clubs |
Other Cars |
FAQs |
Gifts |
Member Photo Galleries |
Member Directory |
Classifieds |
Manuals |
*Buddy Registry |
*Mileage Registry |
Polls |
What's New |
Raffle |
Photo of the Month |
Sponsors]
[Main Performance Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
It's all about pressure ratios
Posted by SteveW (more from SteveW) on Wed, 7 Dec 2005 07:48:54
In Reply to: Im gona get some viggen #s from 5000 ft if possible, jak
[Profile/Gallery]
, Wed, 7 Dec 2005 06:04:12
Members do not see ads below this line. - Help Keep This Site Online - Signup
I'm just talking off the top of my head, I should look it up but my server is real slow this am. To determine PR you take your gauge reading, add the ambient air pressure, then divide that number by the ambient pressure. Examples:
Sea level- 20psi gauge+14.7 ambient/14.7=PR of 2.36
5000' 20psi 12.2 /12.2= 2.63
7500' 20 11 /11 = 2.8
So if your turbo can achieve the limits sets by your software/hardware, there should be minimum altitude correction up to the point where compressor efficientcy limits start to fall off, generally over the 2.4PR range. So there probably is some sliding scale correction factor available, but it would be specific to the car and elevation. It also seems a little inconcievable that a dyno shop in Colorado doesn't know this.
posted by 69.39.6...
Posts in this Thread:
- john williams pulls only change 9 psi base boost, jak
, Thu, 1 Dec 2005 10:47:40- JAK...., Vigge, Mon, 5 Dec 2005 03:24:44
- I know you love me :-), jak
, Tue, 6 Dec 2005 20:13:50- Re: I know you love me :-), Vigge, Tue, 6 Dec 2005 23:34:03
- Im gona get some viggen #s from 5000 ft if possible, jak
, Wed, 7 Dec 2005 06:04:12- Re: Im gona get some viggen #s from 5000 ft if possible, vigge, Wed, 7 Dec 2005 12:13:51
- It's all about pressure ratios, SteveW, Wed, 7 Dec 2005 07:48:54 <-- Viewing This Message
- Re: It's all about pressure ratios, Vigge, Wed, 7 Dec 2005 11:33:12
- I keep forgetting to talk about the compressor wheels.., John Williams
, Wed, 7 Dec 2005 21:37:05 - Turbo car and pressure..., John Williams
, Wed, 7 Dec 2005 21:12:55- some more, vigge, Fri, 9 Dec 2005 05:39:10
- Sounds about right, I just pulled the specs at 300hp., John Williams
, Fri, 9 Dec 2005 13:44:33- Re: Sounds about right, I just pulled the specs at 300hp., Terry, Fri, 9 Dec 2005 21:12:12
- Also....., Terry, Fri, 9 Dec 2005 21:47:24
- Thanks Terry, thats the answer I was looking for...., John Williams
, Sat, 10 Dec 2005 10:06:48- A/F, vigge, Sat, 10 Dec 2005 11:14:15
- Re: A/F, John Williams
, Sat, 10 Dec 2005 16:32:03
- also just to be clear, jak
, Fri, 2 Dec 2005 08:11:38 - what I know is on there?, jak
, Thu, 1 Dec 2005 15:50:21 - Re: john williams pulls only change 9 psi base boost, nathanb, Thu, 1 Dec 2005 10:59:49
Members do not see ads below this line. - Help Keep This Site Online - Signup
Post a Followup
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
StateOfNine.com
![](/tsn/xyz/stateofninebutton.gif) |
SaabClub.com
![](/tsn/xyz/scnabutton.gif) |
Jak Stoll Performance
![](/tsn/xyz/jakstollbutton.gif) |
M Car Covers
![](/tsn/xyz/mcarcoversbutton.gif) |
Ad Available
![](/tsn/xyz/buttonavailable.gif) |
![](/tsn/images/tsnmap.gif)
Random Saabnet.com Member Gallery Photos (Click Image)
This is a moderated bulletin board - Posting is a privilege, not a right.
Unsolicited commercial postings are not allowed (no spam). Please, no For Sale or Wanted postings, SERIOUSLY.
Classifieds are to be listed in The Saab Network Classifieds pages.
This is a problem solving forum for over 250,000 Saab owners, so expect to see
problems discussed here even though our cars are generally very reliable. This is not an anything goes
type of forum. Saabnet.com has been a moderated forum since 1988. For usage guidelines, see the
Saabnet.com Mission and Purpose Page. Please remember that you are
not anonymous. Site Contact | Site Donations | Other Sites by SP -
Poverty2Prosperity.org | Run Club Menlo Park | ScreenBot
Site Members do not see red text instructions, bottom of the page anchor ads, or box ads.
Click here to see all
the Site Membership Benefits!