Hi all new to the site, Just bought mi sen a 99 uk impreza wi 58k and a few minor mods

Wanting to up the power to a reliable 280 - 300bhp and wondered which is the best way to go, am i better with a upgraded ecu and decat pipes etc

id be greatful of any help

Not had an impreza since 2004 and mi old one was a 2000 import running 308bhp so never upgraded that 1

Heres a couple of pics of the new one

Cheers Andy

 

Your looking at a full exhaust system (decat/sportscat) a dry panel filter and a remap, that will get you 270ish bhp, if you want more then its upgrade the turbo time, new fuel pump etc.

Tony

 

Yikes. Andy, Tony's on the money re. power upgrade recommendations but there are a couple of bits under your bonnet that aren't standard, so at this point it might be worth you having a good look to ensure that you know exactly what you've got before going any further.

The first thing that sticks out (literally) is the 97/98MY turbo hotside "chimney". It looks like a normal TD04 actuator beneath it but, next time you're under the bonnet, have a good look at the information stamped on the turbo compressor housing ID plate and just check it says TD04L.

The other thing that's obvious is that there's an induction kit fitted, and, not only that, it looks as though there's a welded aluminium section linking the MAF tube to the intake pipe that runs under the inlet manifold.

In an ideal world the best thing to do with that induction kit is to get rid and replace with standard stuff and a good panel filter. However, if that pipe really is made of metal, the advice to get rid turns into a strong and reasonably urgent recommendation. The airflow sensors in these cars are very easily damaged by vibration, and sticking a solid link pipe there instead of the flexible OE piece will be vibrating it a lot.

The consequences of that scenario are a damaged airflow meter and, once some enthusiastic driving is added in, a dead engine. If the car was sold with its standard induction bits, fitting them ASAP would be a good idea. Also worth at least getting the airflow meter checked to make sure it isn't already jiggered.

 

sorry to hi-jack the thread but how do you check the MAF? is it possible to check it's resistance with a multi-meter? if so what readings should be present?

 

The only 100% authoritative way to test them is on a flow bench, where a known quantity of air can be pushed through and the response of the sensor checked against it.

The only authoritative way to check one in situ is by datalogging the sensor output (or the ECU MAF voltage data channel) at high frequency when the car's being driven and checking that the response follows changes in engine speed and pressure, and doesn't drop out or under-read.

No. The airflow meter isn't anything like as simple as a variable resistor, so you can't just stick some test probes on it and from the number you get determine with confidence whether it's good or not.

As above it's not about resistance. We can tell you that the output of an MY99-00 sensor with the engine off should be between 1.02 and 1.06 volts with hot idle between 1.2 and 1.34 or so. However, for reasons that are obvious, it doesn't really matter what the sensor reads at idle. When you really need it to be accurate is at the upper end of its dynamic range, when the engine is under boost and sucking in large quantities of air.

The only way to check them under those conditions without bench equipment is to log the sensor voltage, and (it's easier to draw this than describe it) check for the presence either of consistent under-read or transient drops in voltage that don't correspond with a throttle lift.

In practice the best way to catch one in the early stages of failure is usually with an AFR meter or knock monitor. The former will pick up the leaning in AFRs that an under-reading sensor causes, and the latter will detect the consequences of the leaning.

 

thanks for the in-depth responce (I'll put the multi meter away) I've no reason to suspect there's anything wrong with mine I was just interested to know if it was something I could check myself just for peace of mind,

 

BTW nice looking car, very clean and tidy, much nicer than my horrible heap although I'd guess you paid a lot more than I did,

but as the saying goes 'you pay peanuts you get monkeys' mine definitely a 'baboon' of a car and looks like it was maintained by monkeys!!! By contrast yours looks a like a real nice genuine car and obviously been well looked after.

 

In terms of the remap component of the upgrade!

Peronally I'd no longer advocate an Ecutek Remap of the std ECU for a MY99/00. I'd go with Simtek (I've had both).

A number of reasons:

1) Simtek is just a superior ECU to the JECS unit and will give your mapper facilities to give you a better map: improved resolution, live mapping, twin maps etc...
2) The Jecs ECU has an emissions boost cut facility built into it that can't be mapped out - annoying and potentially dangerous IMHO - think of judging an overtake assuming you'll have full performance then only getting .5 bar of boost). No such nonsense with Simtek.
3) Jecs does not offer in gear boost compensation (you want this!!!!). It's there with Simtek
4) Simtek does away with the MY99/00's weak spot (and potential engine killer) the MAF!

Simtek fitted and mapped circa 1k, Ecutek (assuming you have to pay the licence) circa £650. The former is WELL worth the extra IMHO!

 

Yes it can. Just because EcuTeK haven't worked out how to do something doesn't mean it can't be done.

See above. Ditto a load of other clever things. Tek have done next to no real development on the 99/00 platform for years, primarily because they've had no competition on it. Which seems a bit of a swizz for people who are paying the same licensing cost as on the cars which are still benefiting from ongoing R&D.

Your points about the relative differences Simtek and the Jecs are sound but they're not necessarily down to a lack of capability within the ECU. It's a shame really as it's a lot more powerful than many would probably expect.

 

Thanks alot for the info mate, im going to check the turbo and a few other bits now, ill post details up shortly, the tube is metal mate so ill get on the bay asap for a oe 1, so its the standard airbox and induction pipes i need and a decent panel filter, Wheres best place to take air flow meter for checking ? or is it worth just buying a new one

Once again thanks alot mate, really greatful for the info

 

Lol pmsl, Mine was £2500

 

Bargain!! looks v nice

 

looks nice car for thr money, mine was a £1000, no tax , test or history, it's now tested but I'm waiting till thurs to tax it.

 

Cheers mate, everything seems ok up to press did 400 miles in it over weekend wi no probs so should be ok fingers toes n nuts crossed

 

Yep. Have a look at the holes through into the inner wing cavity to see if the OE resonator is still there. If it is, that's one less thing you need to source and refit.

In your position I'd just buy a new one and have done with it. Aside from the risk that that horrid metal pipe has already caused some mischief, you get the reassurance that you're working from a known platform from this point forward.

 

Cheers mate, i am right thinking mines got 2 cats ? so 2 decat pipes needed ?
Its got a pro drive s/s fitted but looks like cats are still there

Ive checked turbo and tbh it looks like a new en ( got TD04L stamped on bottom left of flat id plate)

Induction pipe is plastic apart from that ally bit in middle so ill do away wi pipercross and buy a standard air box n panel filter

Whats a good make panel filter ? K&N etc

 

The resonators still there, the pipes plastic apart from the obvious ally bit in middle so ill do away with that asap,

Is it best to go to subaru main stealers for a new air flow meter ???

sorry for all the questions but my last impreza was a nightmare from day 1 tbh, was a w reg bought in 2004 for 10k lasted 1 day and bottom end went, took em 3 weeks to mend then only lasted 2 months and went again, ended up wi over 17k in it and only did 7000 miles ;-(

 

****e that's not a good outcome, can understand the caution!

Yes, main dealer's the obvious option for an AFM, or someone like Import Car Parts - Japanese car parts for Subaru, Nissan, Honda, Toyota, Lexus, Mitsubishi and more that sells genuine ones. Part number's 22794AA010.

 

[quote=Splitpin;9316659]****e that's not a good outcome, can understand the caution!

Yes, main dealer's the obvious option for an AFM, or someone like Import Car Parts - Japanese car parts for Subaru, Nissan, Honda, Toyota, Lexus, Mitsubishi and more that sells genuine ones. Part number's 22794AA010.[/quote

Thanks mate ill get a new en ordered asap, Ive found a pipe to the right of the turbo ( about 1 1/2 inch bore ) thats been removed and capped off??? any ideas what its for, ill post a pic on here in 5 mins

Thanks again mate

 

That'll be the recirculation line for the dump valve. It's capped because you have that aftermarket atmospheric one on.

If it was mine I'd find an OE dumpvalve for £not much on eBay, refit that and flog the aftermarket one. You should be a few quid up on the transaction and your engine will thank you.

 

will do mate, i liked the dump valve noise but after a day it was doing my head in tbh

Also while i think on, is turbo chatter due to the induction kit as ive got loads of chatter

 

Not quite. The chatter is actually being caused by the dumpvalve's opening pressure being incorrectly calibrated. However, because you have the induction kit on, it sounds a lot more obvious than it would do on the standard bits.

Whoever owned that car before you really did just about everything possible to volunteer it for a major problem. Chatter in combination with that aluminium trumpet will be having very interesting effects on the airflow meter.

Yet another reason to fit the standard DV and induction parts soonish - and then new airflow meter afterwards.