soulsea

Sorry if this has been covered before, but I'm trying to figure out how/why MB is getting so much more HP/TQ out of 4LTT in the 18 E63S (603/627) vs the 18 GTR (577/516).

Is it that they're holding back peak hp/tq for the Black Series?
Is it just a matter of a tune to get that back?

What am I missing?

Thanks

Vic55

I believe its all about the boost. Others can probably chime in with more articulate details.

AMG 17GT

E63 is AWD and can handle the traction issues. That’s probably why it’s rated much higher, although I suspect the GTR to be in the mid-550s.

ericweng

i think its because of the overall performance and handling... A GT with over 600+ Hp and 600tq will not turn and exit a corner as well.

thecutter64

The E63 uses new twin scroll turbos versus single scroll in the GTR.

the E63 is AwD but it’s heavier. Weight distribution is different . Doubt it will smoke a GTR

soulsea

Thanks for the responses.

I'm thinking that MB could have used the twin scroll turbos in the GTR, or whatever it is doing to get the extra hp/tq of the E63S, and isn't cause they're saving the performance for the BS.

I'm pretty sure figuring out how to put down the power on a RWD GTR isn't an issue ... if Chevy can put down 650/650 I'm certain MB can too.

FourT6and2

With an aftermarket tune, the same engine is getting 600+ hp. So I don't think one needs different turbos to achieve that. It's just how MB decided to tune the car for best traction, I'm guessing. And they are absolutely holding back power fro the Black Series. The engine in the GTR is the same as the GTC, GTS, and older GT, right? MB have been holding power back for years...

ItalianJoe1

The GTR has the twin scroll turbos just like the E63. The power is more about balance/control, the car with 600+ becomes harder to manage around a track, as it is, it works very well with a slight rear weight bias and 2 wheel drive.

The getrag gearbox may also have lower torque limits than the MB trans used in the regular cars.

PeterUbers

Think if hp:weight ratio, not total hp per car

the gtr weighs how much less than the e63S, 1500bs? That’s 150hp right there

soulsea

I understand that and it makes sense.

But my question isn’t about comparing performance between the gtr and the e63s, it’s trying to understand why MB didn’t tune the gtr to the e63s numbers.

My (and others’) guess is that they’re not trying to make the gtr the best AMG gt trim possible, just the best in its segment, ie 991.2 gt3, and they’re saving the max package for the BS which will be priced closer to the 991.2 GT2RS or 991.2 GT3RS and will need to compete with it.

I guess normally no one would notice if they didn’t decide to release a sedan with more power with the same engine.

descartesfool

I seem to recall that when asked about that, Tobias had said that it was due to packaging. The E class has considerably more room for cooling being a larger platform, and that is why they could tune it for more power. The GT being considerably smaller cannot fit as large a complement of all the radiator cores for the various systems, and so they could not cool it as effectively as the E class. The more power a car has, the more cooling it needs. If you run a car on track at full speed or on an autobahn, you need a ton of cooling for high HP cars. It makes me wonder if tuned GT's can actually handle the extra power without overheating on track.

MalibuScott

With the very long front end of the GT I would think there would be plenty of room for cooling capacity.

AMG 17GT

Agreed, but Still very curious to see what they get from the tune on this car.

emericr

Great points already made. Here's my 2 cents.
Due to the limitation of the RWD set up, the chassis seems to be at its horsepower limit as demonstrated during the world greatest drag race. GTR got the same 11.4 time as the GTS but its slightly higher trap speed proves it probably has 600hp. Too bad McLaren and AMG are no longer partners because the magicians at ML are able to put the power down with over700hp.
Due the lower torque limitation on the DCT, Mercedes needed to lower the torque. I think the higher torque is also a problem on the track as it is available really low in the RPM range and that would easily unsettle the balance. Randy hinted at this in his latest video and stated the GTS felt actually more planted. Obviously in his competent hands, he was able to tame the beast and turn faster lap.
Finally, the larger turbos on the GTR will be unleashed with a tune and it will get you the same hp as a tuned E63. The E will be quicker to 60 with AWD but past 100mph, the GTR should catch up due to quicker DCT and lower weight.
I know it would add some weight but I can't stop dreaming about an AWD GTBS with a hybrid electric set up with 800hp

ItalianJoe1

DCT alone isn't gonna be better at higher speeds. The MCT box is just as efficient and has more gears, meaning it's in more of the powerband all the time. Hard to overcome the extra 2 gears even with a dual clutch box.

emericr

Having owned both, I do believe the DCT responds and shifts much quicker. Racing in Mexico, I can attest that on every gearshift the GT gains a bit at every shifts against the 7 speed DCT. I have not run against the new 9 speed.

ItalianJoe1

7-7, yes the DCT is an advantage. 7dct - 9mct, the gearing will help more.

I'm assuming the rear end ratios are unchanged, if the 9mct gets a longer axle ratio than the 7mct cars, it may not be enough. I don't know that part.

descartesfool

No there really isn't much more room available for more coolers in a GT or to get more air into the existing coolers. Just open the hood and have a look for yourself. It is possible to squeeze a tiny bit more in there as Dime Racing has done, but an E class just has more width and space than a GT in the front compartment. In any case airflow is the means to do all of the cooling, so one has to be able to increase airflow to get more cooling.

Hammer Down

Earlier this year when the press got ahold of these two beast it was written that the E63S kept up with the GTR on the straights.

The GTR does not have twin scroll turbos. It does however have larger turbos than the GT/GTS.