[Guest]

Hi all. I apologize if this question/topic has been flogged to death before. From what other people have told me and from various posts on these and other boards, I'd come to expect that installing a free-breathing air filter/intake and a high-end exhaust system on an Evo 5/6 would provide between 20-30 additional HP over stock. This assumes no other mods, and leaving the boost alone.

However, I was told by a local high-performance tuning/race-prep shop that just slapping on an intake and exahust will only net an increase of about 5-10 HP. They sell many of these products themselves, and their comments are based on their own experiences setting up various Evos. The shop has a rolling road and have prepped Mitsu Evo's, Eclipses and even Honda Civics to well over 500HP (dyno-tested), so they seem to know what they're talking about.

What are people's experiences with filter/exhaust upgrades? I was keen on investing in these (for my as-yet completely stock Evo5,) but if performance gains are marginal (i.e., 5-10HP) then I may think twice. Thoughts please?

Thanks, and cheers!

 

[Guest]

It all depends on the design of the parts you are fitting.
Many people have reported 25bhp gain from fitting a Magnex exhaust system alone with R/R plots to prove it. That really suprised me and I think the owners were suprised aswell!
I think you are right though, with the correct parts you can gain 20-30Bhp from the filter and exhaust alone. This does suggest that the OE items are not that good at their job.

 

[Guest]

I speculate that the OE bits do their job only too well!

The exhaust in particular may be designed to keep the BHP within industry limits.

 

[Guest]

Yes industry limits! We are talking about the 276Bhp self imposed Jap limit. Upgraded the filter and exhaust and gain some more.

 

[Guest]

Hesperus,

Heave Ho 6 is right. I had my car rolling roaded just before and just after fitting a full Magnex exhaust system and gained exactly 25bhp with no other changes. Surprised, yes; chuffed, absolutely! This is possibly the most cost effective mod for an Evo. A decent filter should give another 5bhp or so.

Steve.

 

[Guest]

SteveC,
What mods do you have and have you suffered any fuel cuts since modding?

 

[Guest]

I understand 280ps is legal limit in Japan.
But somewhere somehow will that be any possibility that the car is actually more than 280ps then the manufacture figure? Due to the regulation the manufacture only claim 280ps.

For instance, I think the power output on EVOs ,Skyline GTR, Impreza 22B are actually more than the manufacture claim.

In my opinion, 25BHP gained on the exhaust and intake are possible but has anyone try before and after fitting the parts on the rolling road ....to give you a more fair figure?

Rolling road reading comes out with 315bhp then you think you have 25bhp gained by fittin gthose parts..but maybe the car was alreay 300BHP before the parts fitted.

The above are just my assumption...

 

[Guest]

James I suggest you read the thread before replying as it would save you some typing http://www.ltregister.f9.co.uk/graphics/wink1.gif border|EQU| 0 align|EQU| absmiddle >

I quote from SteveC

[QUOTE]

I had my car rolling roaded just before and just after fitting a full Magnex exhaust system and gained exactly 25bhp with no other changes.

[/QUOTE]

The standard E6 is 276bhp (280PS) as are all other Jap motors. I think you will find that 22b and all the others you mention are also 280PS even though some people may have stated that they were higher it has been found on R/R that they aren't.

 

[Guest]

HH6.....My GTR has 326bhp...bog standard!!! The 280PS mark may be correct with evos but don't spread untrue roumors around.

Check the GTR register and ask Joss, the moderator, what his standard GTR pushed out on a rr session!!

 

[Guest]

Many thanks for all your replies!

Now I'm wondering if it has something to do with the kind of exhaust fitted. I'm well aware of the Magnex units, having read about them in publication and catalogs many times before. However, they are not available here in the Philppines, and the shipping cost would be rather prohibitive if ordered one.

Aftermarket mods aren't that widely available for petrol-heads in this country. The few shops that bring them in usually carry Japanese brands such as Greddy, 5Zigen, Spoon, Tanabe, HKS, etc. I haven't seen any HKS units here in a while thoug. The exhaust that I'm eyeing is made by Tanabe (3 pipe, semi-freeflow silencer). Is anyone out there familiar with Tanabe, and with these Japanese brands in general? My pocketbook is still smarting from the price of the car, so if this exhaust is all show but not much go, then I'll pass on it!

Okitenik, from other posts of yours I've read, I have the impression you live in Japan? Any thoughts?

Thanks again, and cheers!

 

[Guest]

Many thanks for all your replies!

Now I'm wondering if it has something to do with the kind of exhaust fitted. I'm well aware of the Magnex units, having read about them in publication and catalogs many times before. However, they are not available here in the Philppines, and the shipping cost would be rather prohibitive if ordered one.

Aftermarket mods aren't that widely available for petrol-heads in this country. The few shops that bring them in usually carry Japanese brands such as Greddy, 5Zigen, Spoon, Tanabe, HKS, etc. I haven't seen any HKS units here in a while thoug. The exhaust that I'm eyeing is made by Tanabe (3 pipe, semi-freeflow silencer). Is anyone out there familiar with Tanabe, and with these Japanese brands in general? My pocketbook is still smarting from the price of the car, so if this exhaust is all show but not much go, then I'll pass on it!

Okitenik, from other posts of yours I've read, I have the impression you live in Japan? Any thoughts?

Thanks again, and cheers!

 

[Guest]

Oops! Sorry for the double-post!

 

[Guest]

Untrue rumours http://www.ltregister.f9.co.uk/graphics/tongue1.gif border|EQU| 0 align|EQU| absmiddle >
OK it maybe the case for the GTR and you have figures to prove it but the number of times people have said the 22B was more powerful than 280PS and R/R figures have proved otherwise. I originally thought the limit was rubbish aswell when researching all matters to do with Grey Imports but it seems to be more strict than I thought.

btw are R33 and R34 GTR's 4WS? I can never remember.

Cheers

 

[Guest]

HH,

To answer your question about mods, the only mod I have at present is the full Magnex system. I suffered two fuel cuts about 10 minutes apart on a very cold wet night in March (near zero degrees and damp) when on full chat - has not happened since. However will be getting a remap before winter so this will not happen again. I know what fuel cuts can do and don't want to stuff the engine.

Steve.

 

[Guest]

HH6 - I've got the full Magnex system and a Blitz filter (Steve C - I thought you were getting a Blitz filter?) and have never had any fuel cuts. I originally also had the grommet removed, but one fuel cut incident was enough to make me put it back in (although the turbo boosted higher momentarily, before the ECU reigned it in and the car was definitely faster).

 

[Guest]

After reading this thread and a number of other similar I wonder whether Mitsubshi deliberatley fitted some sort of restrictor in the exhaust system. A 5-10hp increase is certainly what would normally be expected from an exhaust chnage. However there are now so many reported cases of the magnex system giving a 25hp increase (measured before and after on the same day) that this seems to be the real situation.

Has anyone checked out the standard system to see where the restriction is? Probably its just an inefficient silencer, in which case this could be replaced for almost the same power gains as a full system. However given the realitive costs it may not be worth it.

Incidently because of the inaccuracies in rolling roads over a period of time and the fact that they measure power delivered to the rollers rather than at the flywheel and that power is affected by atmospheric conditions then they should only be used as a comparative measurement (i.e before and after mods) rather than an absolute measuremnet (i.e taking a stock car onto the rollers and expecting it to make manfacturers stated power output).

 

[Guest]

Thanks to all who've replied to my question so far |EQU|) I guess the Magnex system wins overall, based on your feedback. Anyone else tried or heard of Japanese exhausts like Tanabe or Greddy? I don't even know if I can find an HKS system where I live (Philippines).

Also, my mechanic says that the stock aircleaner/intake housing seems to have some restrictor which, if removed should allow the engine to breathe substantially better. He was peering into the airbox, and saw something which he suggested can be removed. I'll eventually be upgrading to an aftermarket intake, but is anyone familiar with such a restricting compenent? My car is an Evo5 by the way.

Cheers!

 

[Guest]

Be cautious about removing any of the “honeycomb” material in the airflow meter. It is put there to straighten the airflow. The meter measures the rate of formation of vortices in the lea of an obstruction. The faster the orderly air flows, the more frequently they form. Removing material from the wrong place can create a less orderly air stream and hamper the function of the meter.

The stock meter actually flows quite a bit of air!

 

[Guest]

Hi Daryl,

Long time no hear. I was going to get the Blitz done back in March but Dragon's shipment of filters got held up in customs so they were out of stock when I went there http://www.ltregister.f9.co.uk/graphics/Sad.gif border|EQU| 0 align|EQU| middle > . The beast is booked in for three weeks time to get it done, along with a few other goodies. Full report to follow next month, after an airing at Cadwell. (Interested?)

Steve.

 

[Guest]

If you improve the breathing by using a better air filter, you can increase the risk of pinking/ detonation, by altering the fuel/ air mixture. Make sure your ecu is adjusting for this on a rolling road test. Mark Sheed uses a length of tuned copper pipe bolted to engine case to amplify this, interesting... Always use super unleaded, I add 10% toluene addative on track days to prevent detonation at high revs, but then the ECU has been mapped for this. Part of the increase in exhaust system BHP can be found by removing the cat, and using a by pass pipe, for the first 3 years, then it is still fresh for MOT checks. The magnex and HKS hypermuffler look and sound better than stock system, helps to justify the price. I hear work is being done on enlarged down pipes to increase BHP, anyone tried this yet? keep on reving cleanly, The Bin man.