I have read lots on the subject and i relise that the damage that it can cause is considerable therefore while I like a bit of daft power I would like to do it safely.

The car has been modded with HKS intake and exhaust aswell as hks pfcom, the boost controller is also HKS 3.

The aftermarket boost guage is reading about 1.2bar before I get signs of detonation. Would like to squeeze a bit more out, what sort of mods can I look at to release more boost without encountering detonation.

 

I was thinking cheap first of all:

colder plugs

petrol addatives

Now if I understand things properly the next step is 555 injectors.

 

Could I ask your advice on the cheaper options and any recommendations.

Also with a view to the injectors have I understood how to cure the problem and what would be related costs.

 

Thanks in anticipation

 

Mark

 

1.2 bar is *seriously* pushing your luck on stock turbos and injectors.

 

If I recall, Eric says 1.15 was the absolute maximum you can run on that setup before it's very dangerous.

 

Over 17psi (1.15bar) the stock turbos lose efficiency and you are only gaining 2 or 3bhp - seriously not worth it for the damage you are doing.

 

You need bigger injectors (420s or 555s), and bigger turbos (to flow enough air for that power, without superheating it so much).

 

Colder plugs, and petrol additives will do sweet FA IMHO..

There were a few guys on twinturbo.net that used aquamist waterinjection ( www.aquamist.co.uk ) and pushed around 18.2psi on a stock setup without detonation.

I guess this is the absolute maximum you can get out of the *stock* setup, but your turbos won't last very long...

 

here's some more info:

http://www.twinturbo.net/cgi-bin/ttnet_viewmsg.pl?forum=main&msg_id=696410

 

-Eric

 

[This message has been edited by lymon (edited 05-02-2002).]

Originally posted by aaronjb:

1.2 bar is *seriously* pushing your luck on stock turbos and injectors.

 

If I recall, Eric says 1.15 was the absolute maximum you can run on that setup before it's very dangerous.

 

Guys my mistake sorry I met to write 0.7 to .08 Bar getting my half and full lines mixed up, thats about 11 to 12 psi - which I thought was well within the realms of possibility.

 

Does is still seem unreasonable to squeeze more out?

 

Mark

 

 

I hope you have a JWT-ECU (or similar) ?

I wouldn't even try to get over 11psi on a stock ECU if I were you..

 

with the JWT-chip/ecu you can safely boost up to 1bar/15psi..

if you feel lucky and it's nice and cold outside you can try to go up to 1.15bar

 

-Eric

 

 

 

Originally posted by MCZX:

[bGuys my mistake sorry I met to write 0.7 to .08 Bar getting my half and full lines mixed up, thats about 11 to 12 psi - which I thought was well within the realms of possibility.[/b]

 

Phew that's a whole different ball game

 

I'm with Eric, if you don't have an aftermarket ECU (JWT, SE, MINES etc etc etc) then I wouldn't go over 11psi, the ECU just doesn't have the maps in there for fuelling, and will play guessing games..

dangerous guessing games..

potentially expensive ones at that..

With regards to the ECU, I was under the impression that the pfcom would take care of the fueling, have i miss understood its capabilities?

 

Mark

 

Ps cheers for the replies, its good to be able to chat these things over

That depends on;

 

a) How much adjustment the fuel controller allows (if it's only 10% then you can only up the boost to the limit of that fuelling)

and;

b) Getting it set up on a rolling road for whatever boost level you want to run by someone who knows how to work the fuel controller and knows how to work a wideband O2 sensor setup

As usual way out of my depth at the early stages. I would agree totaly with getting it on the rolling road and getting somebody who knows their stuff to have a look at it.

 

Once again thanks for your help

 

Mark

As usual way out of my depth at the early stages. I would agree totaly with getting it on the rolling road and getting somebody who knows their stuff to have a look at it.

 

Once again thanks for your help

 

Mark

GuyZ you've missed out on the ECU part - the car is running an HKS F-CON V This thing will sort the fuelling out quite nicely This car has had a lot of work done to it - all the upper plenum bolts are numbered so it's anyones guess on internal engine mods really.

 

Mark if you want me to have a look see if there's anything obvious then let me know I need to call you anyway actually - tomorrow evening ok?

 

CheerZ,

 

Andy

 

------------------

Andy - it may have an F-CON V.. it could have an afterburner for all it matters.. but if you whack up the boost without someone setting the fuelling properly, you can wave bye bye to the engine...

 

Oh and one other thing - I don't know the specs on the f-con v, but I think most air/fuel controllers work on a percentage adjustment, which has a limited range.. so if you slapped on huge injectors, you could well find yourself outside of that range, unable to add enough fuel to cope with boost, or remove enough fuel at idle...

 

[This message has been edited by aaronjb (edited 05-02-2002).]

Andy & Aaron

Thanks for the replies, Andy look forward to your call.

I will qualify some of the above, I really enjoy the car, the power as it is creates enough of a smile on my face, however you know how it is sometimes when the devils in ya and you just have to go faster and faster!!! I just want to know that I can put the boost up without worrying about the consequences. And if there is a way of alowing me to enjoy brief moments of .9 or 1 bar of boost and want to way up the pros and cons.

 

Since Andy did his magic the car is smooth, no super smooth and would rather maintain that and current performance than squeeze more out and loose smoothness. In other words I would like to protect what i've got first rather than try to build in more power on weak foundations.

 

Thanks

 

Mark

Originally posted by MCZX:

In other words I would like to protect what i've got first rather than try to build in more power on weak foundations.

 

Possibly the most sensible thing I've seen anyone write in a long time

 

All depends on your injectors and turbos really Mark - if you're running aftermarket injectors and turbos, then you could find yourself able to run mega boost..

 

Stock injectors, stock turbos, and if the f-con allows enough adjustment (and you find someone able to set it up), then I'd say 15psi would be about your limit really, maybe a teeny bit more.. (14.7psi being 1bar)..

 

Have fun