Increasing BHP

[Greg P]

I've had my 3.2 Carrera for 2 years now and have now done all the standard jobs to get it into decent shape including having it resprayed. I'm now looking to get a bhp increase to 250/260bhp.

 

Read the Rolling Road Day article in 911 & PW (July 2007) so had the following thoughts but would welcome others advise.

 

1) Roading Road session to establish current output & provide graphs for further tuning

 

2) Exhaust - thinking M&K, but would like comments including different M&K options

 

3) Chip - thinking Steve Wong

 

4) Roading road session to estabish

 

Thoughts please

[pete917]

I think as a baseline, I'd have a dyno as well as a leakdown and compression test, just to establish the condition of the engine.

 

If your looking for power and keeping money to a minimum, then perhaps in addition to the exhaust, you might consider some cams. The cams really do define the character of the engine. Have you thought about H&S as an exhaust opiton?

[julian]

Pete, excuse my ignorance, but is it possible to install the cams (e.g. 964) without removing the engine? Having done the Steve Wong chip and H&S exhaust route, I'm now itching for the next stage... but I don't want to take the engine out until it's necessary for other reasons.

[oliverjamesthomas]

The engine will need to come out to change the cams, but it isn't a difficult job. Engine removal is a well documented topic both on the internet and in books, if you're fancying a go at it yourself. It also gives a chance for the 'whilst you're at it' jobs, such as a good engine bay and engine clean and inspection.

 

The downside is it also gives the opportunity for other upgrades and if you're an easily tempted type, that can be a problem

[pete917]

Pete, excuse my ignorance, but is it possible to install the cams (e.g. 964) without removing the engine? Having done the Steve Wong chip and H&S exhaust route, I'm now itching for the next stage... but I don't want to take the engine out until it's necessary for other reasons.

 

 

I always take the engine out for most jobs. Its quite easy and quick. Personally I dont think theres enough room to do the cams with the engine in. I think it would be worth it. An exhaust, vams and chip is a good way to spend a reasonably amount of money and get a good return BHP wise!

[B4UL R]

I Have a steve wong chip, along with SSI`s & a M&K muffler, 2+2.....

I also am after more power.

I am thinking engine rebuild `long term`... but for now, cam`s...

 

I keep reading about 964 cams in a 3.2....

 

What gains should you expect?? or is it better to go for aftermarket upgrades?? and if so what make.

 

I`m a VW tech, and would recomend schrick or dougherty all day long in a 16v or VR6 golf, but not sure on what works best in a 3.2

 

Edited August 20, 2007 by B4UL R

[pete917]

I used John from Dougherty. Ive gone for GTII Turbo cams, but you need some good engine management for something that agressive.

 

I would suggest 964 supercup, or maybe even an early S cam.

 

You need to do your research long and hard before choosing cams. I spent ages looking at various options. I even ended up plotting graphs for every profile to look at power delivery bands etc. It can and will change your engine's character. If the lobe centres are too close you'll end up with no power at low revs and everything at 6k plus. Fine for track, not so great for street use. Also, close lobes can run the risk of valves and pistons crashing. Close lobes will also gove rise to reverberation, which will play havoc with getting your emissions down.

 

Personally for a fast street and occasional track, I would go for wider lobes but with some longer dwell and higher lift. This will give you a power band right throughout the rev range and be much more satisfying for use on the street.

Edited August 19, 2007 by pete917

[johndglynn]

I am just putting Bruce's cams on eBay if anyone wants to do reground (964) cams into their 3.2, Camgrinder Dougherty can sort it no probs.

[B4UL R]

I have ordered several sets of vw cams from doughery in the us, and he does me a nice deal so i`ll probably get some from them....

I would like a nice power increase, nothing outragous that would loose torque , what profiles should i ask for??

Is there a list anywhere or site i can look on to check lift/ duration and expected gains?

I`d rather not regrinds.

Thanks

Paul

Edited August 20, 2007 by B4UL R

[pete917]

I have ordered several sets of vw cams from doughery in the us, and he does me a nice deal so i`ll probably get some from them....

I would like a nice power increase, nothing outragous that would loose torque , what profiles should i ask for??

Is there a list anywhere or site i can look on to check lift/ duration and expected gains?

I`d rather not regrinds.

Thanks

Paul

 

Dougherty has a list on his site with the lobe centres, lift and duration. From that you can work out where the peak perfromance and band delivery occurs to give you a guide for what it will do for your engine.

 

As an additional thought, you might like to think about higher flow injectors. The 3.2 standard are pretty much on the limit, and if you go for a high lift profile you'll need to be able to deliver the fuel required.

[topcarrera]

As an additional thought, you might like to think about higher flow injectors. The 3.2 standard are pretty much on the limit, and if you go for a high lift profile you'll need to be able to deliver the fuel required.

 

I think you need to be looking at quite wild cam profiles before fuel delivery is an issue. I have just had 964 cams fitted and the engine remapped (live dyno session). The 964 cams do not seem to compromise torque anywhere through the rev range but certainly provide an extra "zing" at the upper end of the rev range. With the the standard cams I always felt the car to be running out of steam at 6K rpm whereas now the engine feels very urgent all the way to the new (raised) 6,900 rpm redline - really useful on the track.

 

My engine is standard except for a sport rear box (one in one out/3" diam outlet pipe - not sure what make but a nice deep sound, not much noisier than standard), 964 cams and an ecu remap (live rolling road). The car is punching out a tad under 260 bhp at the moment but hopefully this will improve a little as the top-end loosens up a bit (just been rebuilt - standard spec). The car was producing 254 bhp peak (previous re-map) before the rebuild and the fitting of the 964 cams.

 

New 964 cams supplied and fitted, a sport rear box + a "live" rolling road remap (e.g. Wayne Schofield) will give you a noticeable increase in grunt (30+ bhp) for less than £1500 - Good value IMHO.

 

Worth having your car dynoed to start with to check that engine is strong to start with - ideally less than 10 bhp off the "book" 231 figure on a completely standard car.

[jevvy]

New 964 cams supplied and fitted, a sport rear box + a "live" rolling road remap (e.g. Wayne Schofield) will give you a noticeable increase in grunt (30+ bhp) for less than £1500 - Good value IMHO.

 

cams, top end and remap for £1500 is pretty good going - did you get mates rates for the work?

[pete917]

Cams and a map are probably one of the best ways to both improve power and the characterists of the engine for delivering that power. Andy may be right in terms of injectors....it does depend mainly on lift and dwell, and 964's arnt that wild in that respect, so you may not need to the cost of new injectors. I would say, that for an otherwise standard engine, 964 or 964 supercup are your best bet. Any wilder and you'll not be able to map it properly and it will be lumpy at idle and low revs.

[AirCooledExcellence]

cams, top end and remap for £1500 is pretty good going - did you get mates rates for the work?

 

He didn't say that, £1500 for cams & remap

[johndglynn]

He didn't say that, £1500 for cams & remap

£1500 for cams, a muffler and a remap, which I agree with TC is very good value for 30bhp that you can instantly feel in the seat of your pants. Take 100 kilos off and you have even more power to weight.

[jevvy]

He didn't say that, £1500 for cams & remap

 

open yr eyes Jevvy - sorry chaps!

[Richard Bernau]

Supercup grind cams have a very lumpy idle even at 1000rpm and are difficult to pass emissions with - if those are inportant to you. ASk camgrinder for advice on the profile - 964 or Super C2 would be likely suspects.

 

Andy - with 6900 redline, do you have an uprated valvetrain and rod bolts? I can't recall.

[pete917]

Supercup grind cams have a very lumpy idle even at 1000rpm and are difficult to pass emissions with - if those are inportant to you. ASk camgrinder for advice on the profile - 964 or Super C2 would be likely suspects.

 

Andy - with 6900 redline, do you have an uprated valvetrain and rod bolts? I can't recall.

 

The engine management may be the weak link here. If it is, then go down a grade to 964 and avoid the expense of a change in engine management. a 964 profile is still going to offer lots of improvement over stock.

 

IMHO opinion, stiffer springs and retainers and bolts are going to be needed for increased RPM.

Edited August 21, 2007 by pete917

[topcarrera]

Andy - with 6900 redline, do you have an uprated valvetrain and rod bolts? I can't recall.

 

No -

 

Don't think a few hundred rpm is that critical. If I was racing the car I would probably be a bit more cautious. I think anything upto 7000 rpm occasionally is OK, any higher then yes, valve springs, rod bolts etc become potential points of weakness. Wasn't the Clubsport limit set to 6850 rpm?

[pete917]

Perhaps I'm a belt and braces man. (never was very fashionable).

[Beaky]

Is the Hot Film conversion worth throwing into the mix?

 

Depending on which one you use, you can get larger intake capacilty and greater, quicker accuracy in the air mass sensor reading for the ECU - Well that's what I'm told.

 

Prices vary as follows: -

Milford 911 Chips Promax Autothority

£1,075 £1,444 £750 £963

Edited August 21, 2007 by Beaky

[tea boy]

Is the Hot Film conversion worth throwing into the mix?

 

I know a bloke who can get 'hot films' if anyone wants one.

[pete917]

if you do your £'s per BHP sums, then IMHO you are probably better offer getting the Cam and Chip combo. Hot fim allows the airflow meter flap to dissapear therefore reducing impedence of airflow into the manofild and the hot film wire measures airflow quicker without the moving mechanical parts.

Edited August 22, 2007 by pete917

[B4UL R]

Just been in contact with John @ douherty, gunna go with a set of 964`s i recon.

 

 

Next silly question is my new SW chip.. should i get it redone?

 

is it going to be ok, or not?

 

I have the higher octain version with higher rev limiter...

Thanks again chaps

Edited August 21, 2007 by B4UL R

[Richard Bernau]

Is the Hot Film conversion worth throwing into the mix?

 

I don't know if SW has dyno info on his site for the hot film but I have seen 9Ms analysis regarding removing the AFM. On their 3.6 Motec kits they change the intake by removing the AFM altogether and they reckon it is worth ~10-15hp, though this is on engines making 340+hp and flowing a lot more air than our 3.2s. I have also read that the flaper AFM are wide open from about 4500rpm so there isn't that much restriction anyhow.

 

Analysis on 3.2s is less conclusive. I know 89-911 on Pelican took the hot film off his 3.4 as it made it very hard to map correctly.

 

RB