What needs upgrading in a 6A12 to rev harder?

spetz · Post by **spetz** » Sat Dec 02, 2006 1:08 am

Wow that is an interesting engine build
It's for a Mini is it?
How much power, torque and how many revs?

At the same time though, do you think those principles stand for a 6A12? The MIVEC is obviously a much higher tech piece of equipment and might need less work done to it?
Considering, the rpm is only going to be raise by a bit over 1000rpm (say around the 1300-1400rpm range)

At the same time I do realise at such high rpm, every little bit more makes a huge difference

payaya · Post by **payaya** » Sun Dec 10, 2006 12:26 am

khunjeng wrote:I dont think its pointless, it will be expensive.

Take it to a decent tuner. They will have rebulit many engines and give you good advice. But expect that if it revs harder or you make it work harder it may have more frequent issues...

replace all the inetranls...but you need to do everything as the bit you dont replace will be your weakest link...

IN the end...what do you want to get? I car that revs to 10k? I would be more intrested in low down torque, improve that...get better acceleration and that would be nice.

Exactly! A flatter torque and power curve would make a better engine! A lot of people have the believe a 4.0L car producing 150KW compared to a 150KW 2.0L would make them equally as quick. The 4.0L would obviously have a more lazy rpm and also more torque. That equates to more all round power.

The FTO produces max power at 7500 rpm or whatever it is, you hardly ever get max power as your rarely in that rpm! A car that produces max power at say 5000rpm would obviously mean a flatter power curve.

More revs would be nice it would just mean you'll be in the sweet spot longer. But boring out the car to achieve extra capacity would propably be better as your car would produce mroe power all the time!

oldie · Post by **oldie** » Sun Dec 10, 2006 10:44 am

You can't have a flat torque curve AND a flat power curve, power is torque * by revs so with a flat torque line the power curve is also a straigt line but angled up, at the end of the day if your after absolute performance the only numbers that matter are Max HP (or KWs)

spetz · Post by **spetz** » Sun Dec 10, 2006 3:00 pm

I think in a racing application obviously you want more top end

I personally don't much care for low end. So long as it's drivable, I want my power over 5500rpm

PS. Torque gets you moving Oldie

oldie · Post by **oldie** » Sun Dec 10, 2006 8:28 pm

Sorry you'r incorrect, if there's motion, power is what's getting you going. Good torque down low increases low down power

khunjeng · Post by **khunjeng** » Sun Dec 10, 2006 9:55 pm

power and torque are directly related...you dont have one without the other.

and yeah...what payaya said...he's onto the the whole average power concept.

spetz · Post by **spetz** » Mon Dec 11, 2006 4:31 am

I realise they are related
and 5252 rpm they intersect
But then how can they be so related when our 200hp cars make 200nm?
And other 200hp cars make 350nm

khunjeng · Post by **khunjeng** » Mon Dec 11, 2006 7:22 am

spetz wrote:I realise they are related
and 5252 rpm they intersect
But then how can they be so related when our 200hp cars make 200nm?
And other 200hp cars make 350nm

"you realise they are related" - "but then how can they be related?" now thats a intresting statement.

engine capacity and design my friend. How many 2Ltr NA cars make more than 150kw and 200NM of power from 1995?

Newer cars will match this...but thats no suprise...they are newer designed..typically 10 years newer.

So what is your suggestion? and why do u want ot make all your power at max revs? get a new engine.

Post by **Bennoz** » Tue Dec 12, 2006 12:10 am

Irrelevant of what you all think power versus torque is, what do you think makes the quickest car at the end of the day? What makes a quick car is having both HP AND torque. How you mix your HP & torque gives you the application your car is best for.

That mini block described above has not changed in spec for 15 years. Every time I blow it up - I build the block identical to what it was before (unless some new revelation in performance increase was discovered in the block department) it was the best I could make it.

What governs your HP & ft/lb (Kw & Nm) mix is cams.... always is. The beauty of those mini motors is that I have a 'list' of cams I can choose depending on the application of the car.

Here it is:

Note in the Scatter Cam section - the 286 cam gave me 89hp at the wheels at 6800rpm. It also gave me 92ft/lb of torque at the wheels at 6650 rpm. Add that to a 600kg car, add a 50hp NOS kit & it equated to my best 1/4 et of 12.89 @ 126mph. I ran out of gearing.... 7/8's of the way down the track I was redlining 4th (top gear)

The best performance I had with a full race MD315 - 13.78 @ 119mph.
The 315 gave me 94hp at 7725rpm & 95.5ft/lb at 7450rpm on the rollers.

Yet, track times with the 315 were vastly better than the 286... Its all about finding the right mix and application for that mix.

khunjeng · Post by **khunjeng** » Tue Dec 12, 2006 12:21 am

haha good times...

I'm in the middle of looking at cam setups for my other car...intresting stuff.

I guess u can understand why based on the general power band ratings...ones a more average power rating while the other is directed high higher rpm for racing I guess..

Post by **Bennoz** » Tue Dec 12, 2006 12:24 am

A science in itself!

payaya · Post by **payaya** » Fri Dec 22, 2006 9:42 pm

khunjeng wrote:
spetz wrote:I realise they are related
and 5252 rpm they intersect
But then how can they be so related when our 200hp cars make 200nm?
And other 200hp cars make 350nm
"you realise they are related" - "but then how can they be related?" now thats a intresting statement.

engine capacity and design my friend. How many 2Ltr NA cars make more than 150kw and 200NM of power from 1995?

Newer cars will match this...but thats no suprise...they are newer designed..typically 10 years newer.

So what is your suggestion? and why do u want ot make all your power at max revs? get a new engine.

totally agreed but the FTO is always compared to cars with much higher CC's and force induction. Aussies love their big CC cars.

If a FPV Typhoon with 550NM rocks up next to you at a set of lights, he would not car his car produces almost 3x the torque all he cares about is beating you!!

payaya · Post by **payaya** » Fri Dec 22, 2006 9:49 pm

khunjeng wrote:power and torque are directly related...you dont have one without the other.

and yeah...what payaya said...he's onto the the whole average power concept.

Exactly! I would take a 3.0L 120KW 300NM FTO over the GPX.

Power on paper is one thing, but take a look at a Dyno Graph of an FTO, its produces nothing at low rpm and the peak power is only available for a split second.

payaya · Post by **payaya** » Fri Dec 22, 2006 9:58 pm

khunjeng wrote:
spetz wrote:I realise they are related
and 5252 rpm they intersect
But then how can they be so related when our 200hp cars make 200nm?
And other 200hp cars make 350nm
"you realise they are related" - "but then how can they be related?" now thats a intresting statement.

engine capacity and design my friend. How many 2Ltr NA cars make more than 150kw and 200NM of power from 1995?

Newer cars will match this...but thats no suprise...they are newer designed..typically 10 years newer.

So what is your suggestion? and why do u want ot make all your power at max revs? get a new engine.

I find never engines produce more peak power, but torque seems to stay similar.

You only can increase NM's so much with an NA engine. From Falcon EL to BF, you see in increase of about 30NMs. Power has increased 40KW. The M5 is 370KW and around 500NM of torque. About right for 5.0L!

What makes a new car so much more drivable is its Valve timing. The Falcon offers a variable timing on both inlet and outlet valves. So bascially like Mivec but on a much more advanced scale. Mivec is an On/Off swith, the Falcon is a gradual system.

You can safely say, every litre of your engine equates to about 100NM of torque.

Cars with long stokes usually offer better low down performance. FTO is a peaky low stroke motor, which means peaky. Just like an F1 car.

The FTO is 2.0L. Bit of a handicap when you think about it. Theres only so much you can do to a 2.0L.

payaya · Post by **payaya** » Fri Dec 22, 2006 10:01 pm

khunjeng wrote:haha good times...

I'm in the middle of looking at cam setups for my other car...intresting stuff.

I guess u can understand why based on the general power band ratings...ones a more average power rating while the other is directed high higher rpm for racing I guess..

usually why race cars are so high revving is because of regulations. A lot of race categories, have a limit on CC's but usually never RPM.

For you to win, up the RPM! Easy!

If regulations are less of an issue, big CC's would be the go. Audi won La Mans with a diesel this year. Low RPM monsters.

Black_FTOGPX · Post by **Black_FTOGPX** » Tue Dec 26, 2006 12:05 am

easiest and cheapest way to get more top end power out of the FTO is to increase the compression ratio, just get the heads shaved as much as you can, but you will need to run premiem fuel all the time.
Should only cost a couple of hundred bucks

khunjeng · Post by **khunjeng** » Tue Dec 26, 2006 8:44 am

Black_FTOGPX wrote:easiest and cheapest way to get more top end power out of the FTO is to increase the compression ratio, just get the heads shaved as much as you can, but you will need to run premiem fuel all the time.
Should only cost a couple of hundred bucks

who doesn't do this already??? ifu dont...your detonation/knock is really sh*t...even if u dont notice it driving.

spetz · Post by **spetz** » Tue Dec 26, 2006 5:49 pm

Yeah the heads are shaved
I think you can take a maximum of 2mm off and I took around 1.6mm (or haven't yet but will before it gets assembled)

Need to get adjustable cam gears though as cam timing will change
I think it's only costing me $60 to shave them but normally it would cost a bit to remove heads + new head gasket kit

So definately not $200 job