Granturismo MC Trofeo - Road Registered

StuartW

Member
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9,306
One point that wasn't lost on me or rather figure 506bhp. Exactly 10% more then mine.

Same engine etc as the 4.7 road going car

just with a different map...

and running on super...

;)

Indeed & over 400kg lighter plus no ABS or traction control - no wonder Matt needed new underpants after driving it to the MOT station!
 
  • Haha
Reactions: Zep

StuartW

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9,306
Do you know who raced it before Ebor?

Not yet, no. During the 2015 season my car was used more as a floating car for guest drivers so it was entered in 4 of the 6 races of the season, each with different drivers. It's the previous seasons that I am trying to track down which is going to take some time
 

GeoffCapes

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14,000
Not yet, no. During the 2015 season my car was used more as a floating car for guest drivers so it was entered in 4 of the 6 races of the season, each with different drivers. It's the previous seasons that I am trying to track down which is going to take some time

I notice that it was driven by Abbie Eaton, who is also 'The Stig' for The Grand Tour.
 

azapa

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1,300
Wow, just wow. Saw one for sale on an American or Euro website some time ago and dreamed about the idea of owning one! Huge congratulations. Oh, and amazing colour too!
 

ChrissGT

Member
Messages
341
Indeed, if anything it has been slightly uptuned!
The car is in GT4 spec and pre 2016 season when all entrants are taken to the SRO who run the series for the balance of power equalisation, the Maseratis were too quick and restrictors had to be fitted between the throttle body and induction air filter which resulted in the peak power dropping to around 440bhp. I do not have the restrictor fitted on mine and of course the map that was written for it also resulted in a peak power upgrade so it is probably a bit quicker than the regular race cars now. The talent behind the wheel however, that's another story!

You see im no good at engines. Based on your story i was assuming there was less fuel and air being put in the engine after remapping, adding the maf sensor and restricting the exhaust flow somewhat.
 

Ewan

Member
Messages
6,757
I thought that too, Chris. Remap, MAF, and exhaust to meet emissions/MOT would infer a decrease in output, to my mind, but apparently not. This is why I’m not an engineer and don’t work in the auto industry!
 

Oneball

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11,075
I thought that too, Chris. Remap, MAF, and exhaust to meet emissions/MOT would infer a decrease in output, to my mind, but apparently not. This is why I’m not an engineer and don’t work in the auto industry!

If you look at some of the cars racing in GT4 they’re 50-100bhp down on the road cars, GT3 have a bit more power but almost all produce less power than the road cars.
 

Sam McGoo

Member
Messages
1,746
Its very interesting. I would have thought even a race engine would have had a MAF or at least lambda feedback to run at optimum performance.
I know with just a throttle position sensor and a base map it'll run fine, but wouldn't have thought it would be optimal for performance.

Did this maybe originally have an aftermarket Ecu and sensors that were removed prior to sale?
 

Sam McGoo

Member
Messages
1,746
Would be nice to get yours on a rolling road and see what it has in its current state.

Would be good if we could learn from this and get some genuine performance gains from our 4.7 engines. If yours was running over 500, it can obviously be done.
Maybe just need a switchable map for MOT time.
 

Oneball

Member
Messages
11,075
Its very interesting. I would have thought even a race engine would have had a MAF or at least lambda feedback to run at optimum performance.
I know with just a throttle position sensor and a base map it'll run fine, but wouldn't have thought it would be optimal for performance.

Did this maybe originally have an aftermarket Ecu and sensors that were removed prior to sale?


There’s a couple of issues running lambda sensors on race cars. The first is that you spend most of the time at fully open or fully closed throttle and lambda sensors aren’t much help in these scenarios as you aren’t at a steady state. The second problem is that the optimum stoihc ratio varies with throttle opening and especially rpm so you’re better off building a fuel map that varies these throughout the Rev range than you are on allowing the lambda, maf and ecu to do it for you.
 

StuartW

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9,306
If you look at some of the cars racing in GT4 they’re 50-100bhp down on the road cars, GT3 have a bit more power but almost all produce less power than the road cars.


This - based on the majority of the twisty circuits that the GT series tend to use, outright power in a straight line is not what's required, the chassis and suspension set up is key from what I have been told
 

StuartW

Member
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9,306
The race car already had the front lambda sensors fitted but not the rears. But then there were no cats for them to be monitoring so I think were just plugged in as a part of the road car loom which the race car has, I can't see that they were registering any exhaust gas temperatures.

Below is the read out after DMS wrote the map specifically for the car. It was done with the car on their own rolling road and their own software plugged into the ECU. This reading was produced after the cats & lambdas were installed but before the MAF. The only difference to how the car is set up now, to this read out, is the addition of the MAF

65083
 

ChrissGT

Member
Messages
341
Im guessing the biggest difference between a road gts and stuart race car are 200cell cats, manifold and air intake. So it would be interesting to know the difference in air intake and manifolds for those wanting more power.

But i suppose having a baby elephant less to carry around is what makes this car really fast.
 

philw696

Member
Messages
25,123
Getting rid of weight is the easiest way to make something go faster.
No ABS
No A/C
No interior but then the roll cage must be a few kilos.
Lots of wiring and electric motors to lose too.
 

StuartW

Member
Messages
9,306
Getting rid of weight is the easiest way to make something go faster.
No ABS
No A/C
No interior but then the roll cage must be a few kilos.
Lots of wiring and electric motors to lose too.

Very true - no interior fan, no a/c condenser & compressor, no infotainment as well as the weight saving in the plexi vs glass plus the composite panels which are super light too
 

Oneball

Member
Messages
11,075
Getting rid of weight is the easiest way to make something go faster.
No ABS
No A/C
No interior but then the roll cage must be a few kilos.
Lots of wiring and electric motors to lose too.

Kerb weight for my 1969 Vette is 1589kg. Minimum homologated weight which is what I’m aiming for is 1255kg, think how much you could loose from a modern car.
 

philw696

Member
Messages
25,123
Always remember listening to Stuart Turner who was the Competition's Manager for BMC telling us young guns back in the early 80'S that the easiest way to make our cars go faster was to get rid of anything we could and make them lighter.
I think you need to take the Clock out.