Engine overboosting - "thicky" needs help!

OK - here's the deal. My Coupe has a GTEC1 fitted, and amongst other mods, it was recently rolling roaded at the Wirral meet and was found to be over boosting to 1.8 bar! The fuelling is also horrendous, which caused one of the valves to burn away - leaving me with a £1200 repair bill to get the valves re-done & a new one fitted.

Although it is incedibly quick now (272 bhp) I can't afford to damage the engine again. In fact, the guy at the RR suggested I not drive the car until I got it sorted! I have been driving it - gingerley - since then, but have had this at the back of my mind to try and curb the boost. The cheap boost gauge I fitted is probably inaccurate as well, and I don't think the boost regulator fitted is doing it's job.

MABR suggested a Greddy EBC - as did the RR bloke - but these are furiously expensive. I need some advice as to what I can do - un-chipping it is probably not viable as I still want the performance, but more often than not the new chip corrupts the original setting, so it doesn't revert back to the factory setting.

Should I go for an EBC or another top notch PRV? Which one's do I go for? HOw much would they cost inc fitting?What should I avoid? What's good value without being useless (I'd rather pay for a decent one - even a Greddy if needs be - to prevent a major engine failure again!)? HEEELP!!

get the greddy come over ill fit job done,by the way the prv you got now you do no that you undo it to lower the boost

Cheers for the quick response cowboy.

Which Greddy do I go for cowboy? Who does them cheaply (seen a couple on eBay from Japan)? We tried fiddling with the PRV, but the gauge didn't help us find out what was going on - still kept spooling up like crazy! I'll have to bring it over so you can have a peek mate.

no prob at all in every night,stick up a wanted add on here,greddy profec b2

Mona, I just got my Greddy from Japan off ebay, came in 4 days and you get tracking information so you can see check it's progress.... don't be worried to purchase from the seller ' JPS Trading Ltd', here is a Link to their Ebay shop.

Tim.

Thanks to you Tim - is Greddy the one to get then? Which one did you buy & (if's OK to ask) how much? Was it all Japanese writing!?

P.S. HOW gutting was today! Did you go? MOT!

To deal with the most important thing first, I can't believe we lost today, hat's off to Doncaster, that's footy for you I suppose Still, we'll obliterate the league next season and get the team playing properly together, McAllister has done good, he's the man to take us forward. Beckford needs to go, he's been crap for months now and TBH that's where we were let down today..

Anyway, back on topic

I pad £140 + £21 postage, it's a Profec BSpec II, comes with English instructions in the back of the manual Takes about an hour to fit everything. I've put some temporary settings in, but Ross is going to sort it properly for me tomorrow when I meet him to pick some bits up..

MOT!

We were poor - & Donny were less poor, but still poor overall. waccoe forum is going into meltdown! Beckford was crap today - he's probably going next season. ON ON ON!

So is this model sufficent for my needs then? I saw an e-managa ultimate for under £300, but I can't afford to spend loads. Is the Bspec II decent then?

Are you sure that it is the chip causing the overboost - unless you have a novitec then I doubt it is.

If you have a prv at the moment what happens when you adjust it? If you remove the PRV and attach the pipes from each end of it together then you should get 0.6 bar of boost (assuming standard turbo and actuator) if you are not then I would suggest your wastegate may be stuck...

1.8 bar will nuke the car in no time at all on your setup. I'm sure you love the performance, but when you get the issue sorted it simply wont feel as quick coming on boost and in the midrange.

If your boost gauge is C*ap then get a decent one - it's pretty damn important that you can rely on it. What was the gauge showing on the rolling road? You could at least use this as a point of reference. If you do go for a greddy then they also double as a digital gauge with a peak boost memory, so you can knock of the price of a decent gauge.

Right - this is where my thicki-ness come in! I'm assuming it's the chip - what else can cause this suba??

We tried to adjust it, but it appears to be (according to the gauage) still boosting over 1 bar although it should be on the lowest setting (current performance is still 'mental' status!). I'd have to fiddle with the PRV with cowboy's help to test the wastegate - what would cause it to become stuck?? The turbo was replaced with a semi-bybrid (360 bearing) - would that cause it to overboost?

I'm quite willing to sacrifice some performance to save the engine - it's not as if I track day the car or anything. I just want to show the way to some Scoobies & M3's once in a while!

Didn't see the gauge on the RR as I wasn't in the car - it's there for looks mor ethan anything, so if a greddy is better as a gauage as well, then I'll go for that. Where does the Greddy go - under the dashboard?

Have you checked that all the pipes to/from the EBV and turbo are attached? All it takes is for your actuator pipe to come off and your boost will be sky high.

I'm a little bit lost with all this technical stuff - but I'll take your word for it & go and see cowboy. I'm assuming that the garage that fitted the PRV fitted it properly - but I know they're unfamiliar with the Coupe.

From reading the above, I'd say the PRV is installed the wrong way round. Have seen this before - if the 2 small hoses are on the wrong ports, you'll get no pressure relief at all (i.e. no wastegate operation) and therefore yes, about 1.8 bar boost. Amazing performance, but not for very long!

Swap the hoses round, undo (i.e. screw out, anticlockwise) the PRV adjuster, and see how much boost you have then - should be around the 0.6 bar mark.

our even stick the pipes back on the ebv,

I'll PM you to arrange a meet, matey - which I should have done a long time ago....

wow i'm suprised you've left it this long to sort out Iolo!!
should be easy to set up the prv with a decent gauge, when i had my scooby i used the road from my house to gaerwen and got it spot on.
maybe it's one of those dodgy Leeds, heard they are underperforming at the moment!!!!

Did you actually read my post before this one of yours? I suggest that you re-read it, as I answered your question. There are several suggestions there for you to try and diagnose the issue. If you are running a PRV then the chip has NO control over the boost, just the advance and the fuelling.

As mentioned the PRV could also be on the wrong way round.

A boost gauge is for telling what boost you are running, not for looks!

Do you know where the EBV / PRV is under the bonnet? Once you do you can most likely diagnose the issue in about 15 mins.

Mate, thanks for your replies, but I suggest you re-read my title "thicky" needs help! I know where the PRV is, but I haven't got a fccuking clue how it works or what it connects to - I pay (real) men to work on my Coupe i.e. here's some money, make it work! If it gets too technical then it might as well be written in French as I won't know what to do to diagnose the fault. When I bought the gauge, it was in the hope that it would obviously show boost (although usually I'm concentrating too much on the road to watch it - my mate initially pointed out what the boost was when he was in the passenger seat) - as far as I knew, it was working fine! Being pretty was a nice by-product. The RR session proved that it was inaccurate.

The way forwards is to possibly source a Greddy (or equivalent) and see someone that knows what he's doing with a Coupe engine i.e. cowboy, who may also see if the PRV is fitted correctly. The guy I bought the PRV from also checked it out with me on the RR day & was just as stumped as to why it was still going crackers when he'd closed it as much as possible to give the minimum boost. The garage that fittde it appeared competent with jobs like these as well, but they were inesperienced in the Coupe (they have dealt with proper Italian exotica in the past though).

I don't want to come across as ungrateful as I will take on everyone's comments - this is what I did when I had the valve problem and posted it on here; some people were spot on, others not - but I am a bit of a dunce when it comes to certain mechanical things i.e. I'm more interested in the driving experience than the tinkering experience. Luckily it's a great forum with friendly, helpful people.

if you see 1.8 bar again (before getting it sorted) then lift off! use part throttle and low revs to make sure it doesnt go over about 1 to 1.2 bar until then

If the RR operator screwed in the PRV you would get more boost rather than less!

If you know where the PRV is then all you have to do is take the pipes from either end, remove the valve and connect the pipes together - if you get 0.6 bar of boost then the issue is the prv. If you need to get a fitting for joining the pipes then a local B&Q will have the bits you need. You could also try having the valve the other way round - screw it out (not so far that it comes apart) which should give you less boost.

Either way without an accurate gauge you wont be able to set up the boost properly. get an Autometer from ebay - they are pretty good and do not cost the earth.

I'm doing my best to help you here, I'll even talk you through it if you like - but if you are afraid to get your hands slightly dirty then I'm not sure what I can do.

@ MattW - I am driving her like a virgin until she's been sorted. In fact, she's in stasis in the garage at the moment as I have just got a lil' runabout to prevent further damage.

@ Suba - It was the guy who created the PRV that had a bash at turning it down - his name escapes me & I'm too lazy to look at the RR thread to get his forum name - he posts on here anyway. I'll have another stab at it when I get a chance mate - thanks a lot for all your suggestions - it is genuinely appreciated. I'm not afraid to get my hands dirty (hell, I was valeting an engine bay today & the swarfega orange did it's job afterwards! ) it's just that I'm a bit inept at these things & I'm afraid to fccuk up the engine or something!! Hence, asking the experts & getting someone with the confidence locally to kindly have a look at it for me. I'll have a butchers for an autometer on eBay as well.

As an extension to this question, is a Greddy the only (or best) option for what I need?? Any alternatives that work just as well (for less money)?

You wont know if you need a boost controller until you start eliminating what is causing the issue!!!!!!!

Messing about with the PRV is as simple as wiring a plug!

iv got a few prv,s here come over and we will see if its that and bring your old ebv with you,it wont take long to sort it

Cheers cowboy!

Then when it's all set up and working...buy a Greddy.

* 2


Got mine set up nice now and it's great......

i know someone thats selling an hks evc5 if this is of any help mate?

If you buy a Greddy before you sort this problem out, you're wasting your money.

If you buy a Greddy in order to sort this problem out, you're wasting your money.

Which, in "thicky" terms translates into, sort this out before you buy a Greddy because that may not be the answer to your problems. If, for example, you have a stuck wastegate (unlikely IMO but still possible) then your Greddy will be as much use (and make as much difference) as any other cheap set of flashing blue LEDs!

Find your PRV, which will look very similar to this. Pull the rubber hoses off the two spigots (which are the long bits with ridges on in the picture) and refit them the opposite way round from how they are now. Undo the knurled knob as far anti-clockwise as you can without it coming all the way out (be careful, don't screw it all the way out of a spring and ball will fall out and you won't know how to refit them). Tighten the locking ring (on the same thread as the knob, underneath it). Take the car for a drive and admire the newly-reduced 0.6bar boost on your boost gauge. THEN, and only then, decide how you want to tune the car and whether you want/need a flippin Greddy!

If you are capable of putting petrol in the car, you are capable of doing this!!

Agreed.

Crumbs. Best get spanners out & learn - quick! Cheers boys.

It really is quite simple, even for a mechanical numpty like me.

I also had a problem with my coop not liking PRV's and overboosting to 1.7 bar. When H2ypr fitted my Greddy (thanks Ross ) he also changed my boost hoses and boost has been rock steady since. We were both convinced that one of the hoses was split somewhere.

It almost certainly will be something simple and inexpensive (for a change ), it's just a process of elimination.