Jump to content
Sign in to follow this  
Dave.Warlord

Boost Pressure

Recommended Posts

Just about run my C in now after the build but MFA boost test is reading around 2000 which I belive is about 14.5 psi.

Also MFA shows 430 on idle which says to much timing advance but just had the timing setup at MidlandVW. How accurate are these readings?

As its running 68mm pulley, jabba chip and just had stage 5 charger rebuild at G-Werks, I was expecting it to be a little higher than 14.5. Maybe between 16 and 17.

 

I would have said boost leak but all the pipework and IC are new.

Ive read all sorts of stuff on the net about this with a million different answers including the ECU limiting the boost via the ISV.

 

Was toying with swapping the Jabba chip for an SNS but not sure if it will make enough difference to warrant the cash. Is there that much difference after the digi-lags been sorted out? Also it says on the website when ordering to list mods and how much boost you are pushing. As i'm not 100% sure if my reading are right dont know what to do. I did hook up a boost guage to test to but its hard to get an accurate reading with it not being digital and only reading pressure in bar.

 

And opinions or advise would be brill...

Share this post


Link to post
Share on other sites

it is true about bleeding boost over 1 bar, there are a few options.

 

isv re-route into boost pipes, i run this - some people for, some against.

 

you can buy a 1.5bar map sensor (bar-tek) will need remap afterwards.

 

rallye ecu came with the 1.5 bar as standard, but good luck finding one.

Share this post


Link to post
Share on other sites

Head and cam are standard. As far as i could tell with the guage in my lap, 1bar.

 

Never liked the idea of the ISV reroute to be honest. I know we are all divided on this but I say if in doubt leave it alone. I can see wisdom in both sides of the debate :)

 

So If i buy the SNS will that sort out the amount of allowed boost? Or am I gonna have to take it somewhere and have it mapped on the rollers?

Share this post


Link to post
Share on other sites

a while since ive looked at it but i think the map sensor will only read up to a certain number which equates to one bar, and thats as much as it will run. the 1.5 bar has higher numbers and will allow the ecu to adjust settings for the extra boost.

 

search 1.5 bar map sensor g60 on google. think they explain a bit better on there. instructions fo fitting are in german but i can get them translated.

Share this post


Link to post
Share on other sites

I wouldn't trust the MFA readings to be honest. I get a max of 1800 on it and yet I got 230 BHP at the flyweel last week on Stealths rollers with a totally standard engine head. Don't ask me why but I kindof get the feeling the readings can't 'keep up' with the actual pressure, like it's always slightly behind. put in a boost gauge and you'll get a proper reading.

Share this post


Link to post
Share on other sites
I wouldn't trust the MFA readings to be honest. I get a max of 1800 on it and yet I got 230 BHP at the flyweel last week on Stealths rollers with a totally standard engine head. Don't ask me why but I kindof get the feeling the readings can't 'keep up' with the actual pressure, like it's always slightly behind. put in a boost gauge and you'll get a proper reading.

 

oh,so that was you talking to Chris at the end then comparing figures?

Share this post


Link to post
Share on other sites
I wouldn't trust the MFA readings to be honest. I get a max of 1800 on it and yet I got 230 BHP at the flyweel last week on Stealths rollers with a totally standard engine head. Don't ask me why but I kindof get the feeling the readings can't 'keep up' with the actual pressure, like it's always slightly behind. put in a boost gauge and you'll get a proper reading.

 

oh,so that was you talking to Chris at the end then comparing figures?

 

Yep :D was well chuffed with it. Nice to see Chris and Jonathans G60s, something a bit different. Sorry I didn't match you're face to you're username- you didn't take your car did you?

Share this post


Link to post
Share on other sites

Right just took it out for a spin. Red line in 2nd gives a reading of 2000 on the MFA and the boost guage sits just below a bar then seems to jump up a bar just as it hits redline. Dont know if the guage is that good tho. So gettin it remapped is the only way to go then.

 

Not really sure what the procedure is with remapping tbh.

Do they put a new chip in and tune that or do something to the existing one?

I know what they do by altering fuel settings and all that but not how

Share this post


Link to post
Share on other sites
Right just took it out for a spin. Red line in 2nd gives a reading of 2000 on the MFA and the boost guage sits just below a bar then seems to jump up a bar just as it hits redline. Dont know if the guage is that good tho. So gettin it remapped is the only way to go then.

 

Not really sure what the procedure is with remapping tbh.

Do they put a new chip in and tune that or do something to the existing one?

I know what they do by altering fuel settings and all that but not how

 

Sorry I didn't read properly before- you have tried a boost gauge too.

 

If you have a chip to match the pulley I can't see a remap making much of a difference. Do you have a standard intercooler?

Share this post


Link to post
Share on other sites

Haha OK I'll take that as a no... That may make a diff to measured boost, it's more space to fill afterall.

 

You're not far from me, looks like a shiny set up I'll look out for you!

Share this post


Link to post
Share on other sites

I did think of that but I thought as the boost reading is taken from the TB vacuum line it wouldn't make a difference... but I'm no expert.

 

So its not worth remapping, how do I run more than 0.8 bar of boost? Without going to a 65mm pulley.....

Share this post


Link to post
Share on other sites

Hi,

You can fit a 1 bar check valve on the isv outlet. The sensor is 200kpa. So run more than 1 bar boost and it sends a duff signal and your AFR goes lean. German ebay sell the 250kpa sensors. I'd try helping the top end breathe easier rather than running mad boost. Going from 0.8 to 1bar over that piston area gives more than 100N extra push force on those rods. They'll take it, but may not last as long. Having said that, it's a great engine torque riser - adding more boostage. :|

Share this post


Link to post
Share on other sites

i thought the pg and 1h (rallye) ran the sam con rods though?

 

rallye came with 1.5 bar map sensor as standard. assumption would be conrods would be ok with it, the block might not.....

Share this post


Link to post
Share on other sites

Theres no doubt that silly boost will do damage over time but I dont do to many miles and dont kill it everywhere. I just want 215 horses with out spending silly money on block and head work. If I go down that road i'd rather drop a charged vr6 lump in.

 

If I do blow it up i've got a spare head and pistons so I'm halfway there :lol:

Share this post


Link to post
Share on other sites

rallye came with 1.5 bar map sensor as standard.

 

Not all rallye ecu's got them unfortunately...It's a bit hit and miss.

 

Live remap will always be much more accurate and yield better results than an off the shelf chip. If you are seeing 14/15 psi then id be happy with that tbh, because it's the most you will see (15psi) unless you play about with other bits. But even then you are just pumping more air into the same restriction...

 

Fair does, you will use a little extra boost across the rev range, starting lower down (Much like smaller pully)...But it would make more sense to look at the inlet manifold/cam/head to use the boost that's already there. Unless you have a few things yet to possibly change such as exhaust and manifold/good cold air feed, good condition injectors even.

 

Im at a similar stage...15psi and 206bhp...But im going to build an engine that will eat all the boost a G-lader can throw at it, hopefully :D Still a few things to try yet though...Just fitted a magnex (was standard system at 206bhp!) and have a 4-branch sat here too.

 

Neil.

Share this post


Link to post
Share on other sites

Riley is right, eat the boost! At least look at a 268/276 schrick cam to give a bit more at the top end, maybe a ported cast exhaust manifold aswell! :)

Share this post


Link to post
Share on other sites

Ok. I have a spare inlet and out mani so will look into getting the ports matched up to my other head. Always steered away from the cam because i didnt want a lumpy idle but if thats the way to go i'll just have to put up with it.

0.8 bar is about 11.6 psi so if the remap will push that to 15 i'll be happy. Will the live map sort out the digilag or should I go the stage 5 sns route?

Since the latest build the lag is much more noticable now. 2nd is hit and miss and sometimes feels flat. Halfway through 3rd its like a powerband on a crosser.

 

Just for info mods are

S/steel exhaust

Jabba chip and 68mm pulley

Stage 5 charger rebuild at GWerks

FM IC

K&N Panel filter (Soon to be replaced with a Jabba filter)

Share this post


Link to post
Share on other sites

Schrick won't give a lumpy idle, Stock paper filter flows more than a K&N panel filter, I wouldn't go with an open filter the noise above a steady 3k is very annoying, wah wah wah...etc :)

Share this post


Link to post
Share on other sites
The noise is what I want :lol:

 

I love it. Sounds like a really big hoover. My mate had a G60 Golf years ago and its the noise I fell in love with

 

Each to there own! :salute: Oh never really been a believer in the SNS nondigilagcode. I think they just tell the ECU to stop working of the lambda sooner is all! Not really code as such. :shrug:

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...