how to get more power?

[msm]

I need some help here. In rally gr N more or less everything has to be standard. How can you get more power out of a lets say Mitsubishi Lancer?
You have the mapping; what else?
The car has a 32 mm restrictor on the inlet side of the turbo which doesn't really help. Does the design of the restrictor have any importance?

[Chucky]

Do you have much freedom in that? Normally there's pretty strict set of criteria in regard to what comes before and after the restrictor.

I'm also unfamiliar with the car. Is this the turbo EVO we're talking about?

[msm]

no there is not much freedom at all. all parts has to be standard, not modified etc. And yes it is the Lancer Evo turbo I'm talking about.

[greenamex2]

That's the problem with near standard regs, you can spend a heck of a lot of money gaining very little.

Obvious gains are -

- Remapping as already mentioned. This would have to be done on an engine dyno NOT a rolling road.
- Blueprinting the engine, including the turbo.
- Thinner but better oil (engine, gearbox and diffs).
- Experiment (on the engine dyno) with different length restrictors.
- Get hold of the FIA Group N homologation papers and see if Mitsubishi homologated any 'special' parts. You usually get at least a Group N exhaust listed.

[BugEyed]

I'd agree with Denis, but would add the rider of temperatures. :

• Experiment to find the optimum engine coolant temperature - this is often very different between the dyno and the actual car, and the mapping needs to reflect the actual temperature as used in anger in the car.
• Intercooler - maximise the effectiveness of the allowed components.
• Intake temperatures - keep these as low as possible.

HTH

Duncan

[TEAM78]

focus on how you can keep the car on top of the power band,
its a tough situation to be in, certainly challeging anyway, maybe best to sink the money into chassis work, you need to think where the largest gains can be had before spending money and the engine sounds very limited in what your allowed to do,

[Chucky]

Originally Posted by Denis Bassom

- Remapping as already mentioned. This would have to be done on an engine dyno NOT a rolling road.

That's interesting. Why wouldn't you use a rolling road?

[graham bahr]

really you need to use both, the dyno is better at getting totally accurate back to back test results and is easier to make sure you start each power run with identical temps, oil, water, intake charge, it also removes variables such as tyre pressure and temp.

BUT the dyno cannot 100% duplicate the as fitted engine installation so really you need to do both, although if the rolling road you use has modern clever software and a good operator you can get close to dyno consistancy, although in the case of my car now we are really fighting for grip on the rollers even with a boot full of weight and massive sticky slicks, then again we have seen 389bhp at the wheels!

[greenamex2]

Originally Posted by Chucky

That's interesting. Why wouldn't you use a rolling road?

There a fewer variables (engine temp, tyre temp and pressure, transmission temp etc) on an engine dyno to worry about meaning that you can get that little bit better job done.

And we are talking about lots of little gains.

[graham bahr]

Originally Posted by TEAM78

focus on how you can keep the car on top of the power band,
,

A VERY VERY good point, time and time again i've found more speed from a car by getting the gearing right than engine mods, if you cant play with gearing and i include tyres in that as they are a very useful way to tweek the gearing, its about testing time in the learning techniques that really work for your car, such as earlier or later braking and combined with tighter or shallower turns, and learning to left foot brake can be worth lots of ime particulary if your trying to keep a turbo spinning

[knighty]

You need to speak to Mountune, they have done a lot of work on restricted Group-N cars, not to mention WRC cars, and will be able to re-map the engine in order to give you much more drivability

[Carlos]

If more power is difficult I would plump for 1.better driving 2. better handling 3. .less weight. Is it better to spend lots of money for slight amounts of more power or spend the money learning how to really use the power you already have. just a thought.

[Carlos]

Not saying you dont already!!!!!!!

[Al Weyman]

Originally Posted by graham bahr

really you need to use both, the dyno is better at getting totally accurate back to back test results and is easier to make sure you start each power run with identical temps, oil, water, intake charge, it also removes variables such as tyre pressure and temp.

BUT the dyno cannot 100% duplicate the as fitted engine installation so really you need to do both, although if the rolling road you use has modern clever software and a good operator you can get close to dyno consistancy, although in the case of my car now we are really fighting for grip on the rollers even with a boot full of weight and massive sticky slicks, then again we have seen 389bhp at the wheels!

Slightly off topic but that was my point on the Power/Weight ratio formula of the new V8 series, how on earth do they measure it? I had a V8 on the Rollers once and that only had under 400bhp and it would not stay put on the rollers even with two fat blokes in the back and a V6 engine in the hatch for good measure! Oh (back on topic) despite lenghtly discussion here and a bet with the rolling road operator I can assure you (because I tested it on the rolling road session I am talking about) I see a noticable 4 to 6 bhp increase on the dial by turning of the alternator and that is a fact and the total cost was a simple toggle switch and a length of wire!

[graham bahr]

oh i 100% agree Al, especially with todays ecus.

until my bigger injectors arrive my power output is limited, basically i cant rev it past 6000 without melting something, so simply playing with rev limiters will limit power as at 6000 the power curve is still going steeply up, let alone the ecu playing with the boost control, at the moment we have mine on absolute min boost to cut the fuelling to allow it to safely rev to a sensable figure, but we already know the clever electronics will add or remove 100bhp @5000rpm

[Chucky]

Originally Posted by Al Weyman

I see a noticable 4 to 6 bhp increase on the dial by turning of the alternator and that is a fact and the total cost was a simple toggle switch and a length of wire!

Oldest trick in the book for showroom stock classes. Especially late model stuff that has a >80A alternator from the factory.

I am curious to see some English perspectives on the rolling road issue. I only ask as the only one's I've seen over there have been primitve in the least so I kind of knew the answer before I wrote the question.

You can get very good repeatability on the better rolling roads and hub type chassis dyno's. Al's experience with the 400hp tyre smoker on the dyno is a classic case of a crap dyno. The good ones will hold 800 with ease.

[msm]

so what is the optimum place to chage gears? when you're on top of the power curve or a bit later so it starts a bit higher up on the curve on the next gear?

How can lengths of restrictor change the power?

[Al Weyman]

once you have reached the usable power peak I would have thought it was academic just revving for the sakeof it and better to get it back into the band in a lower gear, remember revs kill engines not power.

[Chris Y]

It depends if the upshift drops you out of the power band or not! Sometimes you have to rev just a little higher to get you into the power band when you shift up..

[Tanky]

Not familiar with your particular engine but you could try:

reverse cooling water pump - cool the cylinder head before the block, helps keep the air cool entering the cylinders (bearing in mind that this will induce more friction to v/train components yet still keeping bottom end wear down)

With regard to keeping inlet temps cool try using a composite inlet manifold - less heat conductive then aluminium helping the inlet charge to enter cylinders as cool as possible . Making sure to use use thermal insulating gaskets between inlet and engine.

Ceramic coated exhaust + manifold - This will keep your engine bay temp down and will keep the exhaust gas leaving the engine as hot as possible improving the rate flow which on a turbo engine should be of good benefit.

Alternatively, strap some lead to your right foot!!!!

[greenamex2]

Originally Posted by Tanky

With regard to keeping inlet temps cool try using a composite inlet manifold - less heat conductive then aluminium helping the inlet charge to enter cylinders as cool as possible . Making sure to use use thermal insulating gaskets between inlet and engine.

Ceramic coated exhaust + manifold - This will keep your engine bay temp down and will keep the exhaust gas leaving the engine as hot as possible improving the rate flow which on a turbo engine should be of good benefit.

I doubt if he is allowed to change the manifold material BUT it would be worth seeing if you could use a more insulated material for the inlet and exhaust gaskets.

Agree on the coatings.

[Rubinho]

Mathematically speaking, the car goes faster if you shift just after peak power revs. You are trying to maximise the area under the power curve and for a given gear split this happens when you shift after the peak. Look at slide 23 of this PowerPoint presentation:-

http://www.imeche.org.uk/formulastud...2004%20JH1.pdf

In this slideshow there's also some interesting stuff on designing intakes for restrictors, which is even on-topic for the rest of this thread!

[Notso Swift]

Originally Posted by msm

so what is the optimum place to chage gears? when you're on top of the power curve or a bit later so it starts a bit higher up on the curve on the next gear?

How can lengths of restrictor change the power?

Ideally you change gears so that the power is constant from the higher revs to thelower revs, this is the fastest you can accelerate. In real life it may not be so easy, especially with a restricted turbo where the power drops of really quickly. you need to keep the turbo spinning, and keep it close to the above ideals. I think you will find that you change up to a higher power than you ccahnge from(!)

Poor restrictor design will create a vortex Ideally you will be able to run until the air gets to supersonic speed. More air = more power

No one has said it, but the best thing you can do with a turbo car is run it on the best fuel for your class, combined with the right tune you will pick up 20 BHP, with a 32 mm restrictor that is probably 7% ELF TurboMax or the like , in Aus it is 5 times the cost of Pump 98, but that is the price you pay!

[avsfan733]

CHEAT!

lol jk but in all reality in the states at least its a lot of how much can you get away with.

in your case is it that you must use stock parts or you must use stock parts as stock parts are purchased? maybe when your blueprinting try things like a serious micropolish on all internal surfaces. might also want to see the rules about the restrictor. the Formula SAE restrictors all end up nicely tapered and polished smooth. don't know what your restrictions are but one team changed restrictor materials to something less thermally active because the sucker was closing down due to the cooling flow of the air. its incredibly miniscule but its a gain nevertheless. the alternator trick is a good one. but if your really serious after checking it out and proving it will work in your application consider stripping the alternator and replacing the bearings to gain back a little rotational friction. check your belt tightness and keep it towards the low end (not so much though that your slipping) to prevent radial loading of the pulleys. polish every surface everywhere inside the block and in all the manifolds. maybe extrude hone the manifolds. ceramic coat both intake and exhaust maybe inside and out. it all depends on what is allowed really. what is specifically excluded and what you can get caught doing

[Notso Swift]

FIA restrictors have to be made of a material that is not subjet to a change of more than Z% in size between x and Y temps (can't remember, but it is something like 0.01% at 0 to 140 deg) I race on the circuit, but in a class with restrictos, and they measure ours both before and after an event, ie hot and cold.

The restrictor needs to be within 50 mm of the compresor, so if you went this way, you would be best to use something that is going to expand from the heat soak.