Does anyone have experience with the 'Mongose Full Exhaust from Turbo Back' by Performance Turbo Systems? Fitting it should result in a Big BHP gain (according to PTS). Btw: price = #481

 

Ruud,
I've had the Mongoose system for around 18 months now and can offer the following comments;
1) I rate it as excellent value- even at £480
2) There is a comparitively massive power gain due to both cats being removed (15-20BHP-allegedly-it definitely feels that way-), and the huge bore.
3) Excellent quality + easy to fit (apart from removing the studs holding the turbo-heatshield- quite fiddly.)
4) Downsides are; Having to put back the catalysed exhaust come MOT time (though some people have managed to get through the test with catless exhaust fitted- I might give it a go next MOT)
The system does tend to hang rather low-although I have never grounded the exhaust other than putting the car into my garage.
There is only one rear hanger- and as such you may be best getting uprated rubbers -preferably a pair to fit on the same hanger.
The system is very loud- this may appeal or may not- personally I think it sounds wonderful.

Hope this is some use Ruud. Also check out some of the previous threads on exhausts as there are various comments regarding the Mongoose system and others and the general pros and cons of running a catless exhaust.

 

Does removing the cat. cause problems to the Lamda sensor located there? How does the ECU know about the oxygen level at the exhaust?
Do you have this massive power gain without changing the air filter?
Finally do you have a picture of this exhaust?

 

The Lambda sensor simply screws back into the Mongoose downpipe (it makes no difference to CO2 readings because it is located in front of the cat on the standard exhaust anyway)

Having an uprated air-filter element or induction kit (I've got an HKS Super powerflow induction-system.- Don't you start- Pete Croney!) undoubtedly helps maximise the power-gain.
What I would also say is that I've fitted loads of 'performance'-exhaust systems to various performance cars including ones that do away with the cat, and the Mongoose is far and away the most effective in terms of obvious power liberated I've come across.
No photos I'm afraid, er... all I can do is describe the system as shiny and ,well... big I suppose.
There's the option of 4" rolled in tail-pipe(what I went for), 4" Square t/p and they've just introduced a 'rally-system' , which I presume must be even less silenced and in which case I dread to think what it must be like noise-wise.

 

Rob, from previous threads I understand that you have both the sequential dumpvalve and as mentioned above the full induction kit from HKS fitted. I have a MY97 and am thinking of fitting these two items aswell. I had an SSport exahust fitted yesterday and am very pleased. The only reason I haven't gone for the RAMAir filter replacement aswell is that I believe I may get more power from the full induction kit. My only reservation... is the full HKS induction kit going to be too noisey on an everday car, alot of money if I find it unbearable? If so, are there any kits that are quieter/noisier than others. Your opinions would be gratefully received. How do you rate your seq.dump valve?

Cheers

Paul

 

This thread has really made me think more seriously about changing the exhaust. Having been to Goode's site I am aware that there are other interesting options apart from the Mongoose system:
1. Devil Full System (Twin DTM pipes)
2. Janspeed Full System
3. Scorpion With cat replacement Pipe (4" Tail Pipe)

Has anyone tried any of the above and if yes how do they compare with the Mongoose in terms of noise and increased performance?

 

What about the

Blitz system, or the Trust.

Does DTM on an Impreza really work !!!.

Jonathan

 

Some of the work done recently on the rollers shows that a K&N panel filter will give approx 10bhp. It does sacrifice a little low down panel over the std car. Most of the Induction Kits will give the same and a little more.

The 10bhp was measured on a car already fitted with a performance backbox.

Seems to get 90% of the performance of an induction kit for less money and noise. If thats what youre worried about.

Jonathan

 

Thanks for the information gentlemen, much appreciated. Now to digest, decide and purchase!

 

Paul,
The HKS sequential blow-off valve is an excellent bit of kit and like all the HKS stuff is excellent quality and a doddle to fit. The only thing I would say against it is that it is probably 'over-engineered' for the average tuned Impreza application. My turbo runs at 17psi and while modestly high (standard is 12psi) a normal uprated piston-type dump valve would do the job just as well for around half the price.
(HKS S/B/O Valve=£235+VAT and e.g. Bailey Motorsport Dump valve=£75+Fitting Kit=£47+VAT-available from D.Tweeks)
However if you were planning on extensively tuning the Impreza then obviously the S/B/O valve could handle anything you threw at it (suitable for 500BHP+applications)

The combination of the exhaust,induction-kit and S/B/O valve make for a lot of noise but I use the car on a daily basis and find it all just adds to the driving experience.Though I must say motorway driving(I hardly do any) becomes a bit of a chore because of the noise.

I think you'll find virtually any of the 'induction-kits' that do away with the air-box will prove similarly noisy.

As well as the HKS and Pipercross Vector kits, there is the GGR/K&N system and 'Green Filter' induction kits all offering broadly similar nominal power-gains of 5-8 BHP.

Probably the most interesting one power-wise is the Regal induction-kit combined with their stainless-steel turbo radius pipe(fits directly between the induction kit and the turbo).As a combination the gain is supposed to be 16BHP nominal for £200+vat.
Via a Samco hose, I managed to join the Regal turbo-radius pipe with the HKS induction kit without any difficulty so you're not necessarily limited by the combination
Anyway,I hope all this blabbering on is of some use to you.