m42racer

I have finally pulled the trigger and have decided to go ahead and upgrade my engine to 4.0L. The work will start the 2nd week in January and I will post pics and info as the work progresses. The engine will be dyno'ed and the results will be posted. I have not yet figured out what else I may do, Cams are on the list. The final engine spec must pass emissions so I cannot go to crazy. I'm expecting the 4.0L upgrade will yield way more than expected. No sure just how much, but Cup 4.0L engines make over 480HP.

996FLT6

With that bump in power- u plan to upgrade tranny/ suspension/chassis/brakes as well? Regards. Mike

buckdr1

Happy New Year All
M42, Mind sharing appx. cost ?
Sounds quite interesting

Bill

Carrera GT

Where are you getting the work done; paradox engine builders? : )

m42racer

I have been told that the engines torque output will be controlled by mapping so as not to exceed the stock GT3 street Trans internals. We may have to change the ratios to use the added torque. If we have too, RSR parts could be added. We will see after the dyno.

As for cost, I have yet to find out the total. The conversion is brand new. As soon as I know the total I will post it. We are changing only the bore, so as to keep the cost to a minimum. The long stroke conversion has already been done several times, but the bore only, is new. Hopefully the short stroke will not hurt too much. At least we will have the two versions to compare. I hoping the bore only will be close. The conversion is Pistons, Liners, Cams, Head work, Exhaust and mapping. It all has to meet emissions. I am not concerned about warranty. You cannot have your cake and eat it too. I know it will be done right as the shop doing the work build a lot of Cup and RSR engines. PM me for more details if you are interested.

As soon as the engine is apart, I will keep the info flowing with photo's. The dyno will be video taped and if I can will post the dyno runs. I saw a recent Cup engine dyno'ed with the 4.0L upgrade done and it made huge torque and over 480 HP. It was this engine that made me want to do this. Once this is done and tested, the kit will be for sale and I expect others may want to do the same. You cannot beat displacement.

996FLT6

May I ask how do u map a manual tranny? Is that by ecu or mechanical? Regards. Mike

m42racer

The engine will be mapped on an engine dyno and the engines torque output will be controlled so as not to exceed the Trans ability. I figure we will not even come close to the Trans ability. The engine will be mapped for peak torque on pump gas, so I expect the output to be lower than the Cup engine I saw. The Cup engine run as a 4.0L made huge torque but ran on 100 oct unleaded and was with the "race" exhaust system with mufflers only. It will be interesting to find out what one of these "street" GT3 engines will make as a 4.0L. The Liners will be ready late January, but there is a lot of work to do before then.

va122

Cargraphic has a 4.0 kit but it's like 30k

C.J. Ichiban

the GT3 transmission can handle a lot more power than the stock clutch and the stock differential can...make sure you upgrade those and you should be cool.

340Elise

My Race 340 Elise, built by Forcedfed used a standalone ECU from EFI to contorl everything. It had different torque maps for different gears, and used lower boost for the first two gears vs. the rest (electronic boost control/wastegate). It calculated which gear the car was in by use of a wheel speed sensor and the current RPM that the car was at; it worked flawlessly!

The wheel speed sensor was an aluminum ring with a magnet inside, and was bolted around the rear axle.

m42racer

i looked at the cargraphic kit and spoke to someone who bought one in the UK. The performance numbers never were up to advertised quotes and the cost for this was the deal breaker. We are projecting not disasembling the case, only removing the heads. This should lower the labor costs. The kit I am told will consist of Pistons, Liners, and Cams and Heads on exchange. I hope that the cost will be affordable. I no for sure it will be no where close to the cargraphic cost. A full Cup rebuild with dyno costs less than $20K, so I cannot see how a top end build with Pistons and Liners will come close to this.
I decided to go with US builder who builds a lot of these engines (Cup) and who could show me real live numbers. They recently did a 4.0L upgrade to a Cup engine and I was there to watch the mapping. This engine made over 480 HP and the torque curve never dipped below 300 Ft/lbs from 4000 to 8300 RPM. The cargraphic torque numbers seem to be inflated as the engine in the UK has never been able to even come close to the advertised numbers and race Cup engines do not make as much with open Exhausts.

The Trans will be an issue. I figure it will be changing the ratios for sure. I certainly will be watching everything else. Thanks for the heads up.

As soon as we start this build I will start posting updates. Like I said, the Liners will not be ready until the end of January, but we will stat the disassembly, Head work etc in the 2nd week of this month.

TRAKCAR

Thanks for posting, it will be interesting to see the progress, final cost and results.

ECS

Is it cheaper to go larger displacement rather than higher RPMs (like F1) for hp? If you put $20K into the engine for higher HP/torque via the RPM route what would the bang for the buck be? I have never heard of someone going this route but it sounds intriguing to me.

eclou

might want to contact Garrett here ( grussell ) who did a 4.0l conversion on his 7GT3. I think he has beyond RSR power levels now.

The stock tranny should be good for near 600ft/lbs or more as the box should be the same as on the turbo and GT2. You will likely need to upgrade the pressure plate to the Sachs xxxx752 (~800nm). You can go all the way to the Sachs xxxx764 (~900nm) if needed. Both can be paired with the organic disc Sachs xxxx973 for stock-like effort and drivability. Going to a puck design disc will make parking and traffic creep almost unbearable.

9fan64

good luck m42 ... keep us posted when you can..