Modifying a V6 for more power

vladman · Post by **vladman** » Mon Jul 17, 2006 12:15 pm

Hi,

I'd like to know what modifications can be done to my V6 to up the power (and torque). What I'm NOT interested in is power gains at the expense of reliability/driveablity. I don't want any modifications which will result in having to frequently "tweak" or "fine tune", or have a negative effect on the driveability, i.e. stuttering at certain revs, overheating, reduced torque at lower revs, extremely reduced fuel economy (I understand I should expect a small-to-moderate reduction in fuel economy), or anything else really that differs too much from the norm.

So, what power gains can I expect from some moderate modifications and what could they be? For example, if I changed the complete exhaust system, installed some kind of air induction system, modified/replaced the chip, etc. Also, what effect would such modifications have on the torque, and where in the rev range.

What I'm trying to decide is if any of these mods are actually worth it. The car goes fine as it is, but I'm a power freak and can never have enough power!

But I only paid three grand for this car (1997, R-reg, manual), and I'm not sure it's worth my time and effort and money investing more in it. I know that I'll lose most (if not all) money I invest in the mods...

I hope what I'm trying to achieve is clear, if not, sorry, I can attempt to clarify (if you say what's unclear).

Thanks in advance!

Post by **Welly** » Mon Jul 17, 2006 12:43 pm

Hello Vladman......

One of our Members (V6WAYNE) has had some pretty good results on his V6 Coupe.

There are decent gains to be had from improving the breathing system....If he doesn't notice this tread you could PM him some time.

vladman · Post by **vladman** » Mon Jul 17, 2006 5:16 pm

Thanks Welton.

V6WAYNE · Post by **V6WAYNE** » Mon Jul 17, 2006 10:11 pm

Hello vladman as Welton says ive had so good results from just small tweeks which are full powerflow zorst +decat bmc forced induction kit i also reset the ecu (disconnected battery over night) and i run it on optimax i would like to re map in the future too as that should help a little. bhp up from 210 to 233 and torque up to 240 made a big difference to the way she goes.

vladman · Post by **vladman** » Tue Jul 18, 2006 8:30 am

Hi Wayne,

Thanks for your reply. Can you give me a little bit more detail please, as I don't know very much at all about modding cars... What exhaust do you have, is everything changed all the way from the engine, how much did it cost you, what's a decat (taking the catalyser out? i heard that can have negative effects as it gets rid of some back pressure the engine needs), what induction kit, and also, what does the resetting of the ECU do? Particularly intrigued by that.

Did you have it on the dyno before and after? Do you use any special spark plugs, or is that a little gimmicky?

Thanks again!

Juzza · Post by **Juzza** » Tue Jul 18, 2006 11:43 am

It's worth remembering that V6Wayne has the VVT Engine which has 210bhp as standard as supposed to the 194bhp unit that your car has. Mods may have a different effect on the different motors....

Would be interested to know what you find though!!

vladman · Post by **vladman** » Tue Jul 18, 2006 11:53 am

Yep, I'm aware of that Juzza...

Juzza · Post by **Juzza** » Tue Jul 18, 2006 12:40 pm

Had you thought at all about Nos? I have been led to believe that the engine is strong enough for a good 75bhp jet....Not too sure about it myself though...

vladman · Post by **vladman** » Tue Jul 18, 2006 12:59 pm

Not a fan of NOS myself, I'd rather have an extra 20-30bhp that's always there and on tap, than 75bhp for 10 seconds or whatever with NOS.

V6WAYNE · Post by **V6WAYNE** » Tue Jul 18, 2006 6:19 pm

vladman wrote:Hi Wayne,

Thanks for your reply. Can you give me a little bit more detail please, as I don't know very much at all about modding cars... What exhaust do you have, is everything changed all the way from the engine, how much did it cost you, what's a decat (taking the catalyser out? i heard that can have negative effects as it gets rid of some back pressure the engine needs), what induction kit, and also, what does the resetting of the ECU do? Particularly intrigued by that.

Did you have it on the dyno before and after? Do you use any special spark plugs, or is that a little gimmicky?

Thanks again!

the exhaust is a powerflow its custom made for each car yes decat means i have removed the cats but have the cats on a custom pipe which can be bolted back in at mot time the system is from the down pipe back no negative effects that i know of just more go.

the induction kit is by BMC but there are others.

i did`nt bother with the dyno before as the car should have 210 standard but 3 days after the work was done i had a power run and got 233 and that was without the induction kit.

disconnect the battery to let the ecu reset it can then learn it may make no difference but i gave it a go dont bother with fancy plugs you wont gain any more go.

http://www.powerflowexhausts.net/

niz406 · Post by **niz406** » Tue Jul 18, 2006 7:01 pm

Reseting the ECU after these breating mods alows the o2 sensor and inlet temp sensor to readjust the tim ing and fuelling where needed as there will be a change to the mixture, due to the extra cold / denser air from the cold air feed to then engine.

By resetting it, and then driving hard for a good few miles the car will update the maps to accomodate the changes in breathing... all to do with Air Mass and Oxygen content..

How much HP you thinking of trying to gain ?

vladman · Post by **vladman** » Wed Jul 19, 2006 10:59 am

V6WAYNE wrote:the system is from the down pipe back no negative effects that i know of just more go.

sorry, excuse the total ignorance, but "from the down pipe back" means you kept the "first" OEM bit of pipework that comes directly out of the engine block, and then changed everything back from there, or... ?

Niz406 wrote:How much HP you thinking of trying to gain ?

As much as I realistically can Niz! 15-20, I suppose (and more torque too). Less than that, and I don't think it's worth it. Of course, I wouldn't complain if I could gain even more than that!

What do you guys think doing all this will cost me, roughly? The exhaust (I don't think I'd go for the quad-pipes like on Wayne's, I like to keep the external looks as stock as possible) and the induction kit?

Thanks for your help!

niz406 · Post by **niz406** » Wed Jul 19, 2006 11:08 am

Ok firstly I would recommend the zorst and induction kit, but then if you want even more and your budget would allow it, ported and polished heads, with yes thats right larger valves... using larger valves allows for more air per cubic inch cylinder for cylinder..

Then I would recommend some adjustment to the fuelling, if you can afford it an after market ECU with uprated injectors and fuel pump, unless you want to opt for a third party 5th injector kit ??

Depends on your budget, if you want only a small increase and a sweeter sounding roar from the block then just the zorst and induction filter, if you want mods that will assist with future improvements and give more HP initially then the heads are a good way to start.

I think my next project is going to be a V6 block

I like the roar of a V6 not sure if its going to be a peugeot or a ford cologne v6 though.... peugeot one would be good learning experience, as I've already tampered with the ford unit before !

vladman · Post by **vladman** » Wed Jul 19, 2006 11:32 am

Very much doubt I'd be doing anything more after the exhaust and the induction kit, because I can't afford it, and even if I could, I'm just not sure it would be a wise investment on a car that's nearly 9 years old now.

Recently, I had to have a bracket (that connects and joins the back box with the pipe that runs to it from the engine) made as the old one rotted away. The car sounded GLORIOUS with about an inch gap between this pipe and the back box. Absolutely gorgeous sound when accellerating and on overrun, just a bit tiresome and droning on a longer journey on the motorway. It was a bit too loud actually, I was attracting unwanted attention... I prefer the stealth mode.

niz406 · Post by **niz406** » Wed Jul 19, 2006 11:58 am

Oh no... your one of those... Its 9 years old, not worth throwing money at it kinda people ! ! ! lol

Mine is 10 years old from new it cost the upper reigons of ?19k now has a book value of ?1250 - ?1750 acording to parkers, but because mine is a rare breed its worth more to enthusiasts ! !

like me

It stands me at around the 10k mark, would have been more if I'd of paidf for labour.....lol done most of the work myself..

Its a case of being individual and having something different from the norm in respect to the performance and sound... sure if you want something fast buy something fast, then thats just generic and you will be like every other subaru / evo driver... make a 406 V6 hit 60 in under 5 seconds and you have a car that'll surprise a few people...

Its worth should not be measured in pounds but in enjoyment... if you have the fun factor in your V6 and you want to extend it, do it... push it to or beyond its boundries....