Tuning a standard SL500 306 bhp

[LostKiwi]

Malcolm, I believe you had an r129 500SL at one point? Was it an M119 engine?
The difference in torque between the M119 and M113 is quite noticeable:

m119 Max torque 451Nm @ 4000 rpm, 326bhp @ 5500 rpm.
m113 Max torque 460Nm @ 2750 rpm, 306hp @ 5600 rpm.

The 113 is MUCH lower in the rev range for max torque making it a 'lazier' engine to drive whereas teh m119 is 'peakier' - i.e. to get the m119 to go you need to feed it some revs whereas the m113 will feel more effortless and pull more strongly from low revs.
This is purely down to the location of maximum torque.

Driving my m119 there is a definite feel of it wanting to rev to get the best from it.

 

[Essel]

That would cost more than my house Pete.

You can have my SL55 for much less than your house

 

[television]

Malcolm, I believe you had an r129 500SL at one point? Was it an M119 engine?
The difference in torque between the M119 and M113 is quite noticeable:

m119 Max torque 451Nm @ 4000 rpm, 326bhp @ 5500 rpm.
m113 Max torque 460Nm @ 2750 rpm, 306hp @ 5600 rpm.

The 113 is MUCH lower in the rev range for max torque making it a 'lazier' engine to drive whereas teh m119 is 'peakier' - i.e. to get the m119 to go you need to feed it some revs whereas the m113 will feel more effortless and pull more strongly from low revs.
This is purely down to the location of maximum torque.

Driving my m119 there is a definite feel of it wanting to rev to get the best from it.

I had a 129 with the 112, my 140 420 had the 119, yes I do agree with all you say, the 113 is a lazy engine

 

[davidsl500]

My cars are much nippier if I remove the 50 kg's of equipment continually in the boot..

 

[Craiglxviii]

My cars are much nippier if I remove the 50 kg's of equipment continually in the boot..

I usually park SWMBO in the front passenger seat. Doesn't yours complain?

 

[AMGeed]

I usually park SWMBO in the front passenger seat. Doesn't yours complain?

Have you got the 50kg model?
Mine weighs in a bit more than that................well quite a bit more

 

[SL63 Mark]

The issue with NOS is you need to carry a large tank of the stuff and it runs out very quickly. A 3kg fire extinguisher sized bottle on a system providing 50hp would last about 30 seconds.
If you wanted 100hp you'd need a huge tank.....
Its also not all that easy to get hold of in some parts of the country and it can be expensive.

Yes, but I can see it propelling Malcolm's SL up that hill very quickly indeed.

Probably not the most practical idea, I think the SL500 is a lovely relaxed wafty motor, the engine it has is part of it's character, I am not sure I'd want or need to turn it into a rocketship. If I did I'd buy a Veyron. Oh no, hang on I can't afford one. There's that idea gone out the window.

 

[Craiglxviii]

Have you got the 50kg model?
Mine weighs in a bit more than that................well quite a bit more

LOL no I haven't, I was being optimistic for you

 

[Craiglxviii]

Yes, but I can see it propelling Malcolm's SL up that hill very quickly indeed.

Probably not the most practical idea, I think the SL500 is a lovely relaxed wafty motor, the engine it has is part of it's character, I am not sure I'd want or need to turn it into a rocketship. If I did I'd buy a Veyron. Oh no, hang on I can't afford one. There's that idea gone out the window.

Shoe-horn a Griffon engine into the SL then. There's 40 of them still sat at Coventry Airport.... spares for the Shack.

 

[nyx]

just stick a blower on it. you know you want to.

 

[television]

I have driven the 273 version for 4 hours today, that is quick, just a bit more for the 113 will do fine.

 

[nyx]

even though id only get another 15 hp if i remapped mine i may speak to colin and ask if the torque curve can be lowered to give the feeble 2.4 a bit more oomph at low revs

 

[Craiglxviii]

I have driven the 273 version for 4 hours today, that is quick, just a bit more for the 113 will do fine.

What power does the 273 have in comparison?

 

[television]

113 306hp 460nm 0-60 6.3 30.7 max mpg
273 388hp 530nm 0-60 5.3 34.0 max mpg

 

[Craiglxviii]

Pretty significant delta there.

 

[LostKiwi]

The biggest difference will be felt in the torque.

 

[television]

The biggest difference will be felt in the torque.

You are right of coarse , I can add 20nm just on a tune up, I am too old to be playing with camshafts Thank you for what you have added here.

 

[daveenty]

Sorry, bit late here.

Whilst I appreciate what Alistair is getting at regarding cam changes and such, knowing you as I do, all you really need is a little bit more of the "kick up the bum". In other words, making it a bit more lively on the low down side of things.

A remap would help with this, but air & fuel in and gasses out are the main priorities. Headers (exhaust manifolds to us) were the major factor in helping mine achieve a bit more torque, and you have access to these possibly. Getting more air in is the next one, though not cheap as I've found out unfortunately.

The main thing is, after any modifications, to find a decent person who understands what is happening with the engine and has a proper Dyno. That way you'll appreciate what's been done, though the best Dyno to me is the built in body one. You'll feel the difference in your back when it's slammed against the seat.

 

[turbopete]

throttle bodies? just something i remembered last night when i was laid in bed. a lad i worked with swapped his standard inlet system for a set of throttle bodies (4 cylinder engne admittedly) and the first thing that entered my head was that it sounded glorious! just like the old days when you bolted on a set of weber twin 40s on! (think lotus elan from the 60s for those that remember them)

like the webers, you could also change the length of the trumpets to adjust where the torquew/power was sited (i cant remember which way it worked now, but something says it was shorter trumpets for higher end grunt, longer to get the power lower down but could be the opposite way)

in a nutshell you got all the best bits of each system. the sound and other improvements that came from upgrading carbs, BUT retaining the fuel efficiency/economy of the fuel injection system. (for the record the engine was, IIRC a vauxhall 2.0 16 valve fitted into a Nova)

 

[LostKiwi]

Yes shorter for top end longer for low end grunt.
Changing to separate throttle bodies on a V8 is horrendously expensive and difficult (MAF in particular poses a huge problem).

Malcolm, the best way to get it tuned is by getting a live map. This where the car is put on a dyno and the operator alters parameters and measures the effect to build a custom map for your car optimising it through the entire range.