Chaps, what do we think. I want a cheapy power upgrade. If not a bleed valve, perhaps some other cheap way. Just to tie me over till i make my first mill!!!!!

 

And any ideas on what power I would gain?

With all due respect, if you're not sure on the bleed valve route then you shouldn't consider doing it DIY. There's some discussion on this thread about it ... http://217.158.136.46/forum/showthread.php?s=&threadid=14081

 

Notwithstanding that, I would say that it is the best £ per bhp upgrade and providing it is done with a sufficient safety margin it can be very reliable.

 

Definitely worth considering IF you have faith in the person doing it.

 

Dave

Just read through the whole lot.

 

In summary, if you get a decent tunner chap to fit the bleed valve and wind the timing back, while not pushing this mod to the limit. E.G. Not to much extra boost all could be sweet?

 

If so my questions are now.

 

How much is a decent bleed valve?

 

How many hours would a top chap take to fit one and tune?

 

What is the standard PSI?

 

What is a safe PSI to raise to?

 

What dose this mean in BHP/Performance?

 

Thanks.

 

Mike.

Mike, don't fit a bleed valve - if you want to up the boost in this way then fit boost jets (welding tips ;)). If you are getting to the point of retarding the ignition to stop detting, you are running too much boost - FINAL!!! Another thing is, if you are going to increase the boost you MUST have an accurate boost guage - with boost jets and bleed valves you get 'boost spikes'. These are caused by the actuators taking a time to react when the boost hits the set limit - the boost therefore momentarily goes above the set limit. If you have a boost guage you can see exactly how far these spikes are going.

 

IMO an ecu upgrade would be your best bet first, followed by a boost controller or possibly boost jets (not as much of a problem with an upgraded ecu).

 

HTH

 

CheerZ,

 

Andy

Sorry - yes, my comments all related to boost jets.

 

Cost - 4p or so ! But don't be tempted !

Hmm so boost jets. If there only installed and the boost raised a bit so no detting.

 

What sort of approx bhp will i gain.

 

Im trying to get an angle on wheather it's worth taking the risk?

Its not worth the risk. thats my opinion.

And power wise you wont get an accurate figure because it will be all over the place.

 

Im sure people will tell you they are fine.

I would rather save up and get a decent controller where you can actually put a safty net into it ie. You can have a warning maximum limit ect.

 

Believe me when it all goes wrong youll cry.

How much is a decent boost controller then?

Yep - Warren is spot on - the power gained will be noticeable, as will the hole in your pocket when it all goes bang! Save up and do the job properly ;) You can't always hear detting so you don't know if you are screwing your engine up - have a look on http://www.ebay.co.uk for a blitz/apexi/hks boost controller - HKS EVC4 upwards, Blitz DSBC or SBC-id, Apexi AVC R - All very good models with varying complexity....

 

HTH

 

CheerZ,

 

Andy

Come on guys - lets be a bit balanced.

 

I ran boost jets at 14 psi for a year / 15,000 miles on standard ECU and retarded ignition. Power increase was a lot over standard and didn't have any noticeable fluctuations. It didn't cause any damage and I never got detonation (unless it only happened when the music was turned up!). There are many others who have had no problem.

 

When I had the ECU upgraded then power went up yet more of course. I then had the car for another year / 15,000 miles on that setup and never had the slightest problem (apart from blowing the auto 'box but let's not go there). I know it ran for at least another 12,000 miles after I sold it as the guy who bought it kept ringing me with questions !

 

I don't disagree for a second that if someone can afford to go the boost controller route then that's preferable and allows you to be a little more radical with the boost settings. But IF boost jets are done right then they CAN be a relatively safe and cost effective upgrade.

 

Dave

Im still after this magic BHP number. An estimate even!!!!!

 

How much bhp is noticeable?

Sorry !

 

There's no true science to it but I would suggest that boost jets only, done safely, could give you something in the order of 30-40 bhp.

 

With an ECU as well you could go a bit higher with boost and have more adventurous timing so probably looking at 50-60 bhp.

 

However, it's normal to also be doing intake & exhaust with these sorts of mods.

 

All IMHO ...

 

Dave

Cool that gives me a good idea, ill think with that ill save me pennies!!!

Originally posted by Hairsy

Come on guys - lets be a bit balanced.

 

I ran boost jets at 14 psi for a year / 15,000 miles on standard ECU and retarded ignition. Power increase was a lot over standard and didn't have any noticeable fluctuations. It didn't cause any damage and I never got detonation (unless it only happened when the music was turned up!). There are many others who have had no problem.

 

 

Exactly Dave,

I did 20K with mine and never had a problem

yeah but what about all the ones that did have a problem?

Yours cost you squat.

My car had them fitted to lower the boost because it was a cheap option at the time to sort out Detting?

 

 

 

Net result a 4k rebuild which turned into another 5 k rebuild.

Point is its fine to do, but what is the point of doing something like this to save a few pennies when the risk is far higher.

?

 

And mac what do you have now boost jets or a boost controller?

Originally posted by 300z

 

And mac what do you have now boost jets or a boost controller?

 

Warren you know I have a Blitz SBC?

I had jets fitted since I bought the Z,I did 20k without a single problem.

I fitted a SBC because I was able to buy it at cost price,The SBC gives you much more settings to play and spool;)

If I never had the chance to buy it for cost,then I would have stuck with my jets,they were fine.

Fight, fight, fight. LOL

Originally posted by MAC 1

Warren you know I have a Blitz SBC?

I had jets fitted since I bought the Z,I did 20k without a single problem.

I fitted a SBC because I was able to buy it at cost price,The SBC gives you much more settings to play and spool;)

If I never had the chance to buy it for cost,then I would have stuck with my jets,they were fine.

Well thats the other point of course. Apart from sking :D the Controller can also allow you to run two different or even more different boost settings, ie trundle around town with safty boost, or get going and turn it up :D

 

Maby they fitted KAK jets to my car lmao.

Originally posted by Hairsy

Come on guys - lets be a bit balanced.

 

I ran boost jets at 14 psi for a year / 15,000 miles on standard ECU and retarded ignition. Power increase was a lot over standard and didn't have any noticeable fluctuations. It didn't cause any damage and I never got detonation (unless it only happened when the music was turned up!). There are many others who have had no problem.

 

When I had the ECU upgraded then power went up yet more of course. I then had the car for another year / 15,000 miles on that setup and never had the slightest problem (apart from blowing the auto 'box but let's not go there). I know it ran for at least another 12,000 miles after I sold it as the guy who bought it kept ringing me with questions !

 

I don't disagree for a second that if someone can afford to go the boost controller route then that's preferable and allows you to be a little more radical with the boost settings. But IF boost jets are done right then they CAN be a relatively safe and cost effective upgrade.

 

Dave

 

Have to concur with Hairsy, my car has now done 30,000 with boost jets and only the last 10,000 or so with an SE chip. Like him it was also enough extra power to trash the autobox ! ;)

how bad can they be?? JWT even supply them with their pop charger kit :confused: