Just picked up my 03 STi yesterday, and have a few questions on it.

1) Dump Valve. Its got one fitted, and I love the sound etc it makes. But are they recommended on the car? Can it damage anything? It is adjustable, so could I adjust to to make the car smoother, but still keep some of the noise?


2) Over fuelling. I went to see my mate, who use to be in to cars, and he said he could smell it was over fuelling. Is this due to the dump valve? Is it wasting a lot of fuel. Is it that big of a problem really? The car has an ECOTek ecu, and was mapped by Scooby Clinic.


3) Sometimes when I lift my foot off the throttle, there is a small pop from the exhaust. Is this due to point 2? It seems like its random when it does it.


4) When gassing it, and for example in 4th gear and about to change in to 5th, but then due to the road/traffic I don't change gear, just leave it in 4th and take my foot off the throttle, the car sort of "lurches" forward. Any reason for this? It does it in all gears.


5) Cam Belt change. In general, how much does it cost to get it changed at an independant garage?


6) Injectors. Do I have the pink/550 injectors in my car (if they are the original ones).


Thanks a lot

 

I will answer what I can.

2. Subaru's run rich as standard, but if it has an ECUTek remap already, then I would get that map checked as they should have leaned it out when it was remapped. I would suggest taking it to one of the well regarded mappers (AndyF, Bob Rawle, JGM or Zen) depending on where you are based. If you are planning to have other mods done and the overfuelling is not too bad, then it is worth waiting to have the remap, but from points 3 and 4, it sounds like the current map is not great.

3. Also map related.

4. Probably map related, but could be dump valve.

6. Yes

 

Thanks mate!

 

(5) TSL quoted me £318+vat back in May. I used some guys at Silverstone I was using for some other work on the car at the time and they stung me for over £400. A good mechanic I know locally reckons he can do it in 3hrs so he would be around £200. I guess you could find somewhere in the middle.

 

Just for the Cam Belt being changed?? A local place to me has said £60 labour, then how ever much the belt costs.....

 

What area are you?

 

Re: Number 4, my WRX does this. Can't decide if its part of the cal to reduce kangarooing at low speed and drivetrain shunt or if something is fooked. Doesn't do it at high engine speeds.

Cheers
Icy

 

1,2,3 and 4 are all related to the vta dumpvalve, put the standard re-circ one back on and they will all disappear.

Banny

 

Mines got the standard valve on. Time for a new one then?

 

prices inclusive of cambelt- £60 labour isn't real

 

Barnsey, Im in Whitby, North Yorkshire.

Trev, which isn't the labour real mate?

Banny, thought as much Will be a shame to loose the noise though. I think it sounds great. But obviously isn't doing anything good for the car is it.

 

A cambelt change on a scooby isn't a quick job- if ur getting it done for £60 then either the garage aren't getting anything out of it or it ain't being done like it should be. Have they done one before?-scoobys don't role in everyday-the final bill may be different. I'd just be cautious with who worked on my car especially when I'm expecting it to punish some of the best cars out there.
cheers mate

 

Yeah, they've done Scooby's before. Quite a few I think, and do quite a few performance cars round my area. My friend who has (well just sold) a 400BHP Nissan 200 with around £20k spent on it used them for everything.

But, I do agree with you, it does seem cheap!! Might enquire more about it, with other garages.

 

fair enough if they come reccomended

 

Hope they should be ok. My mate with the Nissan text the owner, and he said £60 plus the price of the belt. So hope they do a good job.

 

hellomate,

can't answer all your questions but what i can tell you is that my 03 sti ppp had a forge dump valve fitted when i got it,since i've taken it off the car is a lot smoother and there's no judder anymore.

 

Cheers Scott, might have to think about putting a re-circ valve back on maybe!

There wouldnt be the dump noise then though would there

 

Is a Dump Valve and a Blow off Valve (BOV) the same thing?

 

Yes, same thing.
You can run a VTA (Vent to Air) BOV with a blow thru MAF setup (with the BOV before the MAF) or if you use a MAP based ecu, but neither are really worthwhile at your power levels.

OE Recirc dump valve seems to be the best for most applications, but you would loose the whoosh.

 

Is there anything I can use to make the car smoother, but still give the whoosh? Or is that impossible? Its either a smooth car, or a rougher car with a whoosh?

Cheers

 

As mentioned,
you can retain your VTA BOV and the whoosh but the costs would not be worth it IMHO (MAP based ECU like the Simtek is £1000 and you would normally only run Blow Thru with a FMIC, which you really don't need at the moment). I don't think there is any other way of running VTA BOV without it causing some running problems ... but if there is, someone on here will know.

 

I see, cheers mate! I cant afford much work at the moment to be honest. I've got an EcoTek ECU, but wouldnt that be up to standard?


Also, for the cam belt issue. I've just been to see the guys at the garage, and he confirmed it would be around £60, and I can bring my own belt. The guy doing it has a WR1, and the other owner of the garage has a heavily modded Evo. So I'm pleased really that it's in safe hands.

Cheers

 

Mate, are you sure it is EcoTek (they seem to do performance additives, not ECU's) and not an EcuTek'd standard ECU (common on Scoobs).

Basic problem is the MAF measures airflow just after the air filter on the intake and adds the right amount of fuel for that amount of air... if you dump the air out to atmosphere after the MAF, the ECU has no way of knowing and is adding enough fuel for the air it measured (hence you have excess fuel going in) and it runs rough.

 

Oh bollocks, sorry it is an ECUTek. Shows how little I know about cars, lol!! I bought it modified, so am just getting to grips with it. So I have a standard ECU but thats just had an ECUTek remap?


Might have to seriously think about getting a Re-Circ valve really then. Does a lot of excess fuel go in? As in would I see an improved return from a tank of petrol?


Thanks for the help dude! Much appreciated!!