PDA

View Full Version : How much boost?



Andre
11-05-2003, 04:40 AM
How much boost does the standard twin turbos push in the legnum vr4 twin turbo ?:cool1:

-LegnumVR4-
12-05-2003, 10:29 AM
0.7 bar INSERT INTO post VALUES (10psi)

Max boost on the standard ECU is 0.9 bar INSERT INTO post VALUES (13psi)
Anymore than this level and the ECU will cut power protecting the engine. 13psi is a safe operating level for the auto transmission, i would think about installing a transmission cooler if u are lifting the boost from stock as the raidiator cooler is crap. More boost can be made if the ECU is changed to an aftermarket one INSERT INTO post VALUES (u can reset the boost limit).

Barry, need to add this somewhere to your info list?

BraindG
12-05-2003, 10:36 AM
Im assuming this is for manual aswell right?

BraindG
12-05-2003, 11:14 AM
added it, the turbos article is the only one ive finished and made pretty :eek: go here (http://www.clubvr4.co.uk/info/articles/showarticle.php?id=28) just for good measure, ive also added it to the genereal FAQ here (http://www.clubvr4.co.uk/info/articles/showarticle.php?id=41)

cheers Rhys

Roadrunner
12-05-2003, 12:16 PM
So, using the standard ECU and upping the boost from 0.7 to 0.9 bar, what would be the likely performance gain? Are we talking massive, or marginal .... ?

Brian

-LegnumVR4-
12-05-2003, 08:23 PM
Originally posted by H.7
So, using the standard ECU and upping the boost from 0.7 to 0.9 bar, what would be the likely performance gain? Are we talking massive, or marginal .... ?

Brian

I knocked 0.4sec's off my 1/4 time so it will be also quicker to the 0-100k's.

As for the manual gear boxes i would say you will just wear your clutch down quicker:D

Brind
12-05-2003, 08:27 PM
Are you using an electronic boost controller from HKS or Blitz or.. ?

-LegnumVR4-
12-05-2003, 08:33 PM
I'm just using a air regulator valve, works fine for now, will update later. U can see my valve in one of th photos in my intake install near the bracket on the MAF.

Brind
12-05-2003, 08:42 PM
Just had a look but I'm not quite sure what I'm looking at.

Is it safe enough engine wise to do it manualy, ie without an electronic gadget?
Obviously you've done it, but would you leave it like that if you couldn't be bothered to change it?

-LegnumVR4-
13-05-2003, 09:57 AM
There is a little round thing in grey that is just sitting near the fuse box and the bracket, thats my valve. I setup my boost level with this valve and a boost guage. I new that it was just above 0.9bar INSERT INTO post VALUES (13psi) when boost cut happens so i just closed the valve until i hit it then dialed it back until it didn't happen. Mine will just go past 0.9 bar then start to back off.

I keeped it the way it is for now, the only problem i've had is the type of fuel i run. I use 96 octane here as that is all we have here but found one product to make the car miss which i think is due to their product having less octane than the others. I haven't had this problem with any others.

If I were u i would just save up for an electronic boost controller, easy to use and to setup, some have a built in boost guage so u are getting 2 in 1.

Brind
13-05-2003, 06:41 PM
Thanks for the rely.:)

Our normal INSERT INTO post VALUES (cheapy.. LOL!) unleaded fuel is 95 octane.
Super unleaded fuel in general is 97 octane.
And Shell OptiMAX is 98 octane.
So we do have higher octane fuel to use, although it's far from cheap.

Pizza
07-12-2006, 08:01 AM
The highest octane available out here in Jamaica is 90octane. Would you suggest upping the boost via adjusting the actuators to 10psi on that fuel?

bradc
07-12-2006, 08:26 AM
Pulling up the old threads eh?

On 90 Octane I would be afraid of doing much to the car to be honest. I would either steal an oil tanker carrying 98 Octane, or look into octane boosters (although you see lots of bad press about them)

Pizza
07-12-2006, 08:38 AM
LOL I was doing a seach for safe boost levels and this one popped up. Thanks for your response bradc. The 90 octane really sucks and the octane boosters are not a daily driving economical option. I would love a little more ummmmph cause i've become accustomed to the stock boost. I will be selling the car soon so it doesn't make sense to spend money on management now so i'll stick to the stock boost. Thanks again.