Bern

I've heard a lot of bad and good things about changing from a standard airbox to an induction kit, what do people think?

I have a standard 96 STI and wondering if an induction kit with cold air feed will improve it or not, has anyone put one on a standard sti?

Pic's would be nice aswell...

jasonius

iTrader: (1)

Try searching, but in a nut shell, not worth it unless you're panning BIG power..

B0DSKI

iTrader: (17)

Very fragile MAFs on classics so to be avoided

ilogikal1

Wouldn't bother unless you're going for big power figures or a FMIC. Early classics have a decent enough MAF IIRC it's the MY99/00 that have problems. Mine's had an induction kit on since I bought it and I've had no trouble with mine

shea2k

I put an Induction kit onto MY98 STi there last week. The jury is out whether I'm keeping it on or not. There are no other modifications to the car as yet, so the differences I feel, good and bad are all down to the induction kit and they are as follows:

Good: Some snort out of it as the turbo sucks in all the oxygen in a 2 mile radius.
Good: The recirculating valve sounds more like a BOV now, even in 1st gear.
Good: On cold mornings (such as this time of the year), the car is like a rocket with all that cold, dense air coming in.

and now....

Bad: Raspy kinda ongoing noise as you can constantly hear the engine breathing in. Sounds like you've an air leak somewhere.
Bad: In my own opinion, it 'feels' like I've more power in 2nd gear, but less in 3rd. And especially seems noticeable in higher revs. Maybe its my imagination, but thats certainly my feeling though.
Bad: I've had a few back fires/pops since fitting it, although, to be honest, this was in the first initial few days when the ECU was im sure, adjusting itself to the new amount of airflow. Doesnt do it nearly as often now.
Bad: (But funny bad) You tend to drive MUCH more harder (if you can imagine so) coz of the noise of the induction! You just wanna hear it go!!!

My conclusion is try it for yourself, I got my whole kit (unbranded) of ebay for £35. It was good enough money, came with a silicone feeder and adaptor and all. Used, though in excellent condition.

Hope this all helps

Bern

Thanks for the helpful reply.

New_scooby_04

iTrader: (4)

As above, not worth it unless

a) you're going for big power/getting an FMIC
b) you really like the noise

If putting one on a JDM STi it's worth getting the car checked by a mapper as with the late classics in particular an induction kit can be all it takes to induce DET.

ns04

petedotuk

I fitted 1 to mo 04 sti and it has produced a lot of surge, 2 ways to cure it, run boost at around 0.8bar or slap on abigger turbo and go for around 380bhp.

The turbo is in the post

B0DSKI

iTrader: (17)

Pete did u get it remapped after u fitted it ??

The rookie

iTrader: (1)

Remapping won't fix surge unless you lower the boost (see the scoobynet project car typeC) compressor surge is caused (when replacing an intake pipe where there was no surge before) by a poor 'quality' (turbulance and non laminar) flow into the compressor, most AM ones are much worse designed than OE.

Simon

shea2k

Honestly?? For real like??? Fitting an induction kit can cause detonation in MY98 JDM Impreza?? How so? Frig me....I'm beginning to think ya can do nothing with these beasts aside from wash them! Whats the craic?

alcazar

iTrader: (2)

JDM cars are mapped to use much higher RON fuel than is available here.

Thus, with too low a fuel quality, an induction kit can fool the MAF, or fek it completely, and result in a weak mixture, and det.

Alcazar

shea2k

Ahhh...but then thats back to the old 'be sure to use Super'

Its nothing to do with having an Induction kit fitted surely?

My understanding of it is that you're getting more air in, the MAF adjusts to feed the right ratio of fuel, fuel and air entire cylinder and bang....etc etc process repeats.

I do expect (and experience) a performance drop when the induction kit starts sucking in hot air from the engine as well as cool air from outside. But aside from that, there should be no immenient threat to the stability surely?!

AlanPPP

iTrader: (2)

That's pretty much what i'd say!

JonMc

iTrader: (51)

So could this be caused by fitting a SAMCO hose between the airbox and inlet hose as it is smooth, even though I have retained the standard airbox?!?

I had assumed it was as a result of fitting a 3" exhaust and removing the third CAT.

Is surge a problem that can lead to further damage or just a pain in the **** until you sort it out

NAY93WRX

iTrader: (3)

With my K+N I/K, Ive had to turn the boost down from 1.2 bar to 1.1 bar as it would hit fuel cut with the I/K especially on a freezing cold day.

Sounds superb though and turning the boost down that slight difference has'nt affected performance...IMO.

Swings and roundabouts mate

New_scooby_04

iTrader: (4)

The maf scaling can need adjusting to account for the induction kit, if I understand it correctly.

Also for the latter JDM models, the ECU was configured to run 100ron, so you'd need to use Vpower and octane booster to be safe. I think it might be the 99/00 models that were so configured though.

If in doubt check, much cheaper than a rebuild! Better safe than sorry.

Ns04

knobby_2000

I removed my induction kit in favour of the standard airbox and an STI panel filter from subaru.
I found the sucking and tssshhhing noise a bit of a pain in the **** after a while and there became an underlying feeling that the car wasn't that happy on the extra air etc anyways, after changing back I feel the car much prefers the airbox and with the performance filter you still get some degree of induction noise but at much higher rpm.

petedotuk

Had it mapped 3 ways 2 try and remove it, Full boost comin in early but it made the surge feel like a misfire, then full boost later on for smoother power delivery hasnt removed it but it is smooth, then boost changed to .8bar which eliminated it but I wasnt happy so went for full boost comin in late on.

petedotuk

If you goto ECUtek's website it explains that the MAF needs adjusting when an induction kit is fitted.

Personnally my advice would b go for the panel filter.

shea2k

I imagine myself reverting back to the standard Airbox soon enough actually. For no other reason than the noise gets a bit 'old' after a while. At the moment, I'm kinda experimenting with a few things. Though, opening the bonnet and seeing an induction kit makes me smirk all the same (I use to work in Halfords....its their fault I like these things now! LOL!)

The rookie

iTrader: (1)

Yes, its not the internal surface that counts, its the shape and effect on the lineraity of airflow out, many silicon hoses have a nasty S-bend just as they enter the turbo, and are really not good!

Yes Compressor surge 'hammers' the wheels/shaft back and forth on the thrust bearing, not good at all....a turbo will certainly fail sonner, but whether thats in a week or 4 instead of 5 years depends on a lot of factors!

Read this as its quite usefull.....https://www.scoobynet.com/scoobynet-...ge-1-a-20.html

If you compare the compressor blades to an aircraft wing it makes it easier to understand....
As an aircraft flies slower it needs to angle its wings more and more to create enough lift to fly, however eventually the wing stalls as the airflow seperates from the top surface and all lift is lost (like a paper airplane, tipping nose up until it stalls, te nose then drops and it accelerates until it unstills, then repats the manouver), in the same way, to achieve high boost pressures at low airflow (ie low engine speed) the effective angle of attack between the blades and airflow increases until again airflow seperates from the back of the blade and it stalls....Now an aircrafts wing is going through nice clean airflow usually, but pilots well know that the stall speed when flying in the turbulent wake of another aircarft can vary wildly, so it is with the compressor, poor quality airflow will mean the blade stalling earlier, however some techniques actually help by adding energy to he airflow, vortex generators on the back of the EVO's add energy to the airflow so it can change direction down the rear screen better and onto the rear wing, some aircraft have vortex generators on the leading edge of the wings to add energy and keep the airflow attached at a lower speed, but its not realistic to put them on compressor blades! Some OE cars have 'flow straighteners' in the pipework aproaching the compressors (like the square meah on the entry to some MAF housings but usually less dense) to literally straighten the flow closer to ideal so that the compressor moves away from its surge line.

Of course the more boost a bigger wheel creates at a lower speed, the worse it will be, so a typeC with quite a big wheel but due to the twin entry able to get on boost much earlier will be worse than the same spec single entry car, while my tiny hairdryer makes lots of boost at low speed, its a small wheel going much faster so nowhere near the surge line and so on.

Simon

JonMc

iTrader: (51)

Okay, so from what I have read I am a little confused - I have what I would consider surge only in 3-5 gears and generally at higher revs, 5000rpm plus. The most confusing thing is I don't hear it, I have seen it on the boost gauge and when I played with the size of the hole in the brass waste-gate restrictor I actually felt, but I think the hole was too small so boost was up to nearly 1.1 bar.

Also the only hose I have changed is the small S-shaped hose that goes from the MAF into the inlet pipe (see pic) and not the actual pipe that runs under the inlet manifold...I wouldn't have though that this would have changed the airflow markedly.



The way I see this now is either replace the original hose between the airbox and the inlet hose (which I don't have), cut the boost, or fit a new (bigger???) turbo and remap it.

I have a larger TMIC and an induction kit (GGR kit) to fit and my plans include new injectors, VF34 or TD05-16G turbo and a remap when funds permit. Clearly, the induction kit will make matter's worse, so I won't fit that now, but will the larger TMIC improve or worsen matters, or make no difference whatsoever? I suspect this will have no impact as it is after the turbo in the airway.

If I have read right, if I cut the boost (using a manual boost controller or dawes device) that will cure the problem in the short term while I get the cash together for the upgrades. Am I right???

The rookie

iTrader: (1)

From what you say you are not getting compressor surge at all, what you have is a boost control system that is not in control, hence fluctauting the boost.

An MBC, Dawes device, bleed or properly set up EBC or remap (by someone who knows what they are doing as the usual caveat) will sort your problem, if you have everything original, the likely issue is the silicon hosing you've fitted flows more than the original stuff and so the boost cotroller isn't running how it should due to the increased flow through the boost control solenoid for any given position, hence playing with the restrictor size has helped by changing the effective pressure across the BCS.

What I suspect is happening is at its expected steady state position its flowing more air than before so your getting more boost and the controller is cycling as it reduces the BCS duty to reduce boost then under and over shooting.

You may find you can fix it by fitting a restrictor in the pipe from the BCS back to the intake pipe sized to about 1.5mm (again you may have to play with that).

Simon

JonMc

iTrader: (51)

Cheers for that, sounds like it's the problem, especially with the new exhaust, I expect it is generally flowing better and probably spooling up quicker, but being my first turbo it's all new to me.

With the future plans including a remap, and potentially an EBC or a 3-port BC, depending on how far I go, this sounds like something that won't really affect me at the moment, especially as I don't get it out much at the moment.