SRT TOMAHAWK VISION GT OT (Now available)

[Cjamesdixie02]

I'm assuming it'll come either:

A: June 18th on a Thursday (it'll be right after GT Academy ends and ideally, will get full attention to itself)

or

B: July.

Possible release dates for the SRT Tomahawk:

June 10th
June 17th
June 24th
June 29th

According to seasonal events, the SRT Tomahawk will very likely be released on June 29th because that's when the Peugeot VGT event expires. It can be released as early as tomorrow or late as the 29th.

 

[masterrawad]

According to seasonal events, the SRT Tomahawk will very likely be released on June 29th because that's when the Peugeot VGT event expires. It can be released as early as tomorrow or late as the 29th.

Not always. There have been several times when two Vision GT's have been released in their own seasonals, such as:

• Nissan and Aston Martin
• Infiniti and Chaparral
• Alpine and faster Alpine

I'm sure I missed others.

 

[sparkytooth]

I don't think PD will output a second update this month.

 

[RACECAR]

Possible release dates for the SRT Tomahawk:

June 10th
June 17th
June 24th
June 29th

According to seasonal events, the SRT Tomahawk will very likely be released on June 29th because that's when the Peugeot VGT event expires. It can be released as early as tomorrow or late as the 29th.

I think you can scratch off June 10th, its tomorrow and its still right smack dab in the middle of the GT Academy/Le Mans 24 Hours hype.

 

[Cjamesdixie02]

I think you can scratch off June 10th, its tomorrow and its still right smack dab in the middle of the GT Academy/Le Mans 24 Hours hype.

Alright, remaining possible release dates:

June 17th
June 24th
June 29th

 

[Thomas__633]

Just saw this car... three things it reminds me of:

I strongly suspect the overall favourite version will be the GTS-R.

 

[silverman_GT]

Just saw this car... three things it reminds me of:

I strongly suspect the overall favourite version will be the GTS-R.

 

[TheProRacer]

The update will probably be on July 14th or 16th.

 

[Niku Driver HC]

The news article on the GT webpage regarding the Tomahawk has been updated with a few additional pictures, as well as the picture above. Other pictures include the 1:4 scale model of the S and "Mr. Gilles driving" (as the caption beneath his picture bluntly says ) during the official presentation of the car in Detroit:

 

[Bo]

I wouldn't mind that model.

 

[Niku Driver HC]

I wouldn't mind that model.

I wouldn't mind having it either, it doesn't look half-bad. Hopefully some toy company will pick the Tomahawk up and create a smaller scale model of it (cough Hot Wheels cough)...

On a different note, some of those preliminary sketches are quite interesting; especially the ones to the right of the picture. That red and white car looks like the love child of a LMP and the "multi-flap" concept of the X, while the GTS-R sketch looks definitely like a touched up racing Viper concept (the front lights give me a Viper vibe, to be honest).

 

[Situation1994]

All i hope for is an interior on all 3 versions

 

[GranTurismo guy]

All i hope for is an interior on all 3 versions

We aren't getting an interior on any. Don't set yourself up for disappointment, it's a VGT.

 

[Niku Driver HC]

We aren't getting an interior on any. Don't set yourself up for disappointment, it's a fixed closed roof VGT.

Fixed that one up a bit for you. A chosen few VGTs have had detailed interiors, but of course most of them have had fixed closed roofs, which usually imply a non-modeled interior (in actual ingame racing, that is)...

 

[leigh991]

Nobody really cant anticipate when the srt comes available. Can't say any more on this

 

[Formidable]

I'm thinking late June, early July is when the SRT will come out. They usually release VGT's at the beginning/end of a month, so that's what I'm thinking

 

[sirjim73]

I'm thinking 29 June or thereabouts as the most likely date for the VGT. Three reasons for this being a suitable date in my honest opinion.
Pikes peak event is 27/28 June and goodwood is 25-28 June.
And the current VGT event ends then too.
So, IF (and that's a big IF) they announce pikes peak track during the weekend it could be announced on Saturday "coming to gt6 on Monday" and IF they update goodwood like they did last year (and that's also a big IF) it could follow the same pattern.
All of the above is supposition and guess work of course, but not inconsistent with each other.
By the way, I also think the reason they won't be at E3 is because any announcement they make will be at Pikes Peak instead. That would fit with their recent pattern of announcing tracks and key info at actual locations or around real life events (which they did for goodwood, silverstone, red bull ring).
(Sorry for long post).

 

[MarchingSaint]

In this video you can see that the SRT Tomahawk is quite the pack a punch i expected it to be, can't wait:tup:
In a side note- the sound too seem ok, expected that kind of nervous sound from a insect-like car, ready to attack its prey.
Edit: and please note the lovely panels, they seem to work wonderfully

 

[Griffith500]

The sound, actually, is way out there, in my opinion - as in, I can't reconcile it as being a V10. The only thing really making any sense to me about it is the 14000+ rpm engine speed, where any unevenness becomes somewhat dominant (think MotoGP bikes).

The "wide angle V10" comment caused me to raise an eyebrow when I saw it. What does "wide angle" even mean in this context, and what is the significance? Does this explain the sound? Didn't it compromise packaging in F1 when they tried it? It didn't affect the sound much, mind you.

Those five exhaust tips might actually turn out to have something to do with it...

 

[sparkytooth]

The sound, actually, is way out there, in my opinion - as in, I can't reconcile it as being a V10. The only thing really making any sense to me about it is the 14000+ rpm engine speed, where any unevenness becomes somewhat dominant (think MotoGP bikes).

The "wide angle V10" comment caused me to raise an eyebrow when I saw it. What does "wide angle" even mean in this context, and what is the significance? Does this explain the sound? Didn't it compromise packaging in F1 when they tried it? It didn't affect the sound much, mind you.

Those five exhaust tips might actually turn out to have something to do with it...

Let's just use the "It just works" argument.

 

[Formidable]

Let's just use the "It just works" argument.

'Cause PD

 

[LeGeNd-1]

The sound, actually, is way out there, in my opinion - as in, I can't reconcile it as being a V10. The only thing really making any sense to me about it is the 14000+ rpm engine speed, where any unevenness becomes somewhat dominant (think MotoGP bikes).

The "wide angle V10" comment caused me to raise an eyebrow when I saw it. What does "wide angle" even mean in this context, and what is the significance? Does this explain the sound? Didn't it compromise packaging in F1 when they tried it? It didn't affect the sound much, mind you.

Those five exhaust tips might actually turn out to have something to do with it...

Wide angle just means that - an angle more than 90 degress between the cylinder banks. They explained it's for a better centre of gravity. No idea how it affects sound.

From the GT website:

The exhaust packaging is just crazy I can't imagine how this thing is supposed to meet the weight figures it says it does, even with a hollow carbon chassis and space age materials and what not.

 

[sparkytooth]

Wide angle just means that - an angle more than 90 degress between the cylinder banks. They explained it's for a better centre of gravity. No idea how it affects sound.

From the GT website:

The exhaust packaging is just crazy I can't imagine how this thing is supposed to meet the weight figures it says it does, even with a hollow carbon chassis and space age materials and what not.

Whoa that's properly silly.

 

[R5]

'Cause PD

More like 'Cause concept car.

 

[Niku Driver HC]

Wide angle just means that - an angle more than 90 degress between the cylinder banks. They explained it's for a better centre of gravity. No idea how it affects sound.

From the GT website:

The exhaust packaging is just crazy I can't imagine how this thing is supposed to meet the weight figures it says it does, even with a hollow carbon chassis and space age materials and what not.

Guess SRT also considered exotic materials for the engine itself, because it's hard to believe that it can weight so little to not affect the car's weight in a big way. Nevertheless, at least it's still a somewhat feasible hybrid V10 engine, and not, say, a laser engine. SRT really went out of their way with this car, huh? "Push the Envelope"... You did that, don't worry.

 

[Griffith500]

Wide angle just means that - an angle more than 90 degress between the cylinder banks. They explained it's for a better centre of gravity. No idea how it affects sound.

From the GT website:

The exhaust packaging is just crazy I can't imagine how this thing is supposed to meet the weight figures it says it does, even with a hollow carbon chassis and space age materials and what not.

Ha, I never saw that... Thanks! 👍

Well, that explains everything, actually. Lower CoG is right, but it tended to get in the way of the airflow around the side of the car, and underneath it too during the ground effect era in F1. Presumably neither is of concern with this car. Cylinder heads are pretty heavy, though, and whilst it's nice to have them low down, having them further out from the central axis of the car might hurt the dynamic response (particularly yaw).

The exhaust packaging is interesting, and fully explains the sound. I told y'all AES could represent any configuration you could think of!

One thing that caught my eye is that this is clearly normally aspirated. That's 310 hp per litre from the X variant, which is supra-F1 performance. Of course, there's nothing stopping them from using different exhaust configurations on each car...

Spoiler: Detailed look at engine / exhaust configuration

The lack of a 90 degree bank angle means a balance shaft is required, and the 144 degree bank angle potentially means there are simultaneous ignitions, assuming each bank is configured as a normal 5 cylinder and the crankshaft is the common pin type.


All of that means the firing order needs attention. The usual (for the VAG and Chrysler engines) is to fire each bank as 1-5-2-3-4 at intervals of 144 degrees, with the corresponding cylinder in the opposite bank firing immediately after (either 72 degrees or 90 degrees later, depending on the bank angle and whether "split pins" are used on the crankshaft). I.e. cylinder 1 in the left bank, then cylinder 1 in the right bank, 5L, 5R, 2L, 2R etc.

The Viper / SRT10 uses a 90 degree bank angle and common big-end crank pins, which means opposite cylinders fire at 90 / 630 degree intervals, and the overall ignition intervals alternate between 90 and 54 degrees (uneven firing) - no balance shaft, only crank counterbalances. Something like the old V10 Audi S6 and S8 use a split pin crank in a 90 degree V10, giving intervals of 72 / 648 between opposite cylinders, and 72 degrees between every ignition (even firing) - it requires a balance shaft. The LFA uses a common pin crank in a 72 degree block, and a different per-bank firing order (the usual inline 5 order, below) - it has no balance shaft, again see below.

With either narrow-angle setup, whilst it has been proven that the sequential firing of opposite cylinders is kindest to the crankshaft (discovered with aero engines in the second world war), there really isn't much of an option to try anything else due to the mechanics of the configuration (10 unique piston phases; compared with 6 for a typical V12).



In the case of the Tomahawk, the 5 cylinder banks are interleaved at 144 degrees, which is the firing interval between cylinders in either bank and, as already stated, this means two cylinders must fire at the same time if a common pin crank is used. This is typically disastrous for crank longevity (also discovered with aero engines during the second world war) unless you can find a firing order which minimises the cyclic stress on the crank. This has historically proven to be of interest even in a race environment (BRM's H16).

The rationale for the 1-5-2-3-4 firing order within a bank is that it maximises the primary imbalance and minimises all other imbalance; a primary imbalance can be tackled with a single crank-speed balance shaft (or simpler crank counterbalances in a 90 degree block), whereas you need various complicated arrangements for higher order imbalance. Crank torsion from gas pressure is really much the same for any 5 cylinder firing order, but this firing order has substantially lower inertial torsion, which is ideal for a high revving engine and smooth idle.

The usual firing order in an inline 5 is actually the one that minimises the primary imbalance (1-2-4-5-3), but no balance shaft is needed with the typical displacements found there, as the secondary imbalance is comparatively small anyway (also LFA). Inline fours have a secondary (more precisely: second order) imbalance, and that's why their balance shafts (originally only used on larger engines) spin at twice crank speed, imparting huge inertia and friction as a result. This is not ideal in a race engine (also LFA).

Using a split-pin crankshaft with a 144 degree bank angle leaves two possibilities: advancing the second bank to regain the true 72 degree intervals and so that opposite cylinders fire sequentially (best for torsion), or delaying it further. The delayed option is best for the central exhaust pairing, but the torsion is a larger problem, I feel and overrides this benefit. Furthermore, a common pin crank is stronger and more rigid, so the reduced torsional excitation benefit of the advanced split is probably negated by the reduction in rigidity and strength of the resultant crankshaft, especially with such a large split angle (72 degrees, larger than any production engine).



So a few things are a given:

• The 144 degree separation of the banks.
• The use of a common pin crankshaft.
• Simultaneous ignitions.
• The likely use of 1-5-2-3-4 within each bank.

So the task now is to find which cylinders fire simultaneously, which can be done by looking at the usual firing order for 72 degree intervals:
1-6-5-10-2-7-3-8-4-9

Then offsetting by delaying the second bank to 144 degrees instead:
1-5- 2- 3-4
9-6-10-7-8

And so the 5 simultaneous ignition pairs are: 1,9; 5,6; 2,10; 3,7; 4,8.
These pairings are probably not too bad in terms of crank torsion, given they are almost symmetrical and closely follow the torsion-friendly individual bank firing order.


Looking at the picture, the exhaust pairings are: 1,2; 3,4; 5,10; 6,7; 8,9.
This gives three lots of 144 / 576 intervals and two lots of 288 / 432.

That is a very unusual setup, but should sound very interesting at low engine speeds - hints of 5 cylinder, boxer four, V8 and even six cylinder growl. At high rpm, it'll just sound like a MotoGP bike, as already stated.


I investigated other firing orders to see which would complement the exhaust layout better (consistent and widest possible intervals for each pipe; the 5,10 pairing will always be 144 / 576), but each one was worse for both the balance aspect and the crank torsion aspect. So this exhaust configuration is likely only for aesthetic reasons, and "just because" (and because AES allows it, without the need for recordings).

A simple swap would be to pair 4,5 and 9,10 leaving 3,8 across the banks, giving four lots of 288 / 432 and one 144 / 576; this would sound sweeter, in my opinion. This is actually how Audi packages its V10 exhausts in front-engine applications, see here.

Using the usual 5 cylinder firing order of 1-2-4-5-3 results in each pipe getting 144 / 576 (only a little tight for pulse tuning), and remains a possibility if a balance shaft is to be avoided, even though the simultaneous ignitions from a common pin crank might end in disaster.


If I could get at the AES file once the car is added to the game, I could confirm the firing order easily.

 

[sparkytooth]

Question is whether the Tomahawk S revs as high as the 90s Xtreme version.

 

[Niku Driver HC]

Ha, I never saw that... Thanks! 👍

Well, that explains everything, actually. Lower CoG is right, but it tended to get in the way of the airflow around the side of the car, and underneath it too during the ground effect era in F1. Presumably neither is of concern with this car. Cylinder heads are pretty heavy, though, and whilst it's nice to have them low down, having them further out from the central axis of the car might hurt the dynamic response (particularly yaw).

The exhaust packaging is interesting, and fully explains the sound. I told y'all AES could represent any configuration you could think of!

One thing that caught my eye is that this is clearly normally aspirated. That's 310 hp per litre from the X variant, which is supra-F1 performance. Of course, there's nothing stopping them from using different exhaust configurations on each car...

Spoiler: Detailed look at engine / exhaust configuration

The lack of a 90 degree bank angle means a balance shaft is required, and the 144 degree bank angle potentially means there are simultaneous ignitions, assuming each bank is configured as a normal 5 cylinder and the crankshaft is the common pin type.


All of that means the firing order needs attention. The usual (for the VAG and Chrysler engines) is to fire each bank as 1-5-2-3-4 at intervals of 144 degrees, with the corresponding cylinder in the opposite bank firing immediately after (either 72 degrees or 90 degrees later, depending on the bank angle and whether "split pins" are used on the crankshaft). I.e. cylinder 1 in the left bank, then cylinder 1 in the right bank, 5L, 5R, 2L, 2R etc.

The Viper / SRT10 uses a 90 degree bank angle and common big-end crank pins, which means opposite cylinders fire at 90 / 630 degree intervals, and the overall ignition intervals alternate between 90 and 54 degrees (uneven firing) - no balance shaft, only crank counterbalances. Something like the old V10 Audi S6 and S8 use a split pin crank in a 90 degree V10, giving intervals of 72 / 648 between opposite cylinders, and 72 degrees between every ignition (even firing) - it requires a balance shaft. The LFA uses a common pin crank in a 72 degree block, and a different per-bank firing order (the usual inline 5 order, below) - it has no balance shaft, again see below.

With either narrow-angle setup, whilst it has been proven that the sequential firing of opposite cylinders is kindest to the crankshaft (discovered with aero engines in the second world war), there really isn't much of an option to try anything else due to the mechanics of the configuration (10 unique piston phases; compared with 6 for a typical V12).



In the case of the Tomahawk, the 5 cylinder banks are interleaved at 144 degrees, which is the firing interval between cylinders in either bank and, as already stated, this means two cylinders must fire at the same time if a common pin crank is used. This is typically disastrous for crank longevity (also discovered with aero engines during the second world war) unless you can find a firing order which minimises the cyclic stress on the crank. This has historically proven to be of interest even in a race environment (BRM's H16).

The rationale for the 1-5-2-3-4 firing order within a bank is that it maximises the primary imbalance and minimises all other imbalance; a primary imbalance can be tackled with a single crank-speed balance shaft (or simpler crank counterbalances in a 90 degree block), whereas you need various complicated arrangements for higher order imbalance. Crank torsion from gas pressure is really much the same for any 5 cylinder firing order, but this firing order has substantially lower inertial torsion, which is ideal for a high revving engine and smooth idle.

The usual firing order in an inline 5 is actually the one that minimises the primary imbalance (1-2-4-5-3), but no balance shaft is needed with the typical displacements found there, as the secondary imbalance is comparatively small anyway (also LFA). Inline fours have a secondary (more precisely: second order) imbalance, and that's why their balance shafts (originally only used on larger engines) spin at twice crank speed, imparting huge inertia and friction as a result. This is not ideal in a race engine (also LFA).

Using a split-pin crankshaft with a 144 degree bank angle leaves two possibilities: advancing the second bank to regain the true 72 degree intervals and so that opposite cylinders fire sequentially (best for torsion), or delaying it further. The delayed option is best for the central exhaust pairing, but the torsion is a larger problem, I feel and overrides this benefit. Furthermore, a common pin crank is stronger and more rigid, so the reduced torsional excitation benefit of the advanced split is probably negated by the reduction in rigidity and strength of the resultant crankshaft, especially with such a large split angle (72 degrees, larger than any production engine).



So a few things are a given:

• The 144 degree separation of the banks.
• The use of a common pin crankshaft.
• Simultaneous ignitions.
• The likely use of 1-5-2-3-4 within each bank.

So the task now is to find which cylinders fire simultaneously, which can be done by looking at the usual firing order for 72 degree intervals:
1-6-5-10-2-7-3-8-4-9

Then offsetting by delaying the second bank to 144 degrees instead:
1-5- 2- 3-4
9-6-10-7-8

And so the 5 simultaneous ignition pairs are: 1,9; 5,6; 2,10; 3,7; 4,8.
These pairings are probably not too bad in terms of crank torsion, given they are almost symmetrical and closely follow the torsion-friendly individual bank firing order.


Looking at the picture, the exhaust pairings are: 1,2; 3,4; 5,10; 6,7; 8,9.
This gives three lots of 144 / 576 intervals and two lots of 288 / 432.

That is a very unusual setup, but should sound very interesting at low engine speeds - hints of 5 cylinder, boxer four, V8 and even six cylinder growl. At high rpm, it'll just sound like a MotoGP bike, as already stated.


I investigated other firing orders to see which would complement the exhaust layout better (consistent and widest possible intervals for each pipe; the 5,10 pairing will always be 144 / 576), but each one was worse for both the balance aspect and the crank torsion aspect. So this exhaust configuration is likely only for aesthetic reasons, and "just because" (and because AES allows it, without the need for recordings).

A simple swap would be to pair 4,5 and 9,10 leaving 3,8 across the banks, giving four lots of 288 / 432 and one 144 / 576; this would sound sweeter, in my opinion. This is actually how Audi packages its V10 exhausts in front-engine applications, see here.

Using the usual 5 cylinder firing order of 1-2-4-5-3 results in each pipe getting 144 / 576 (only a little tight for pulse tuning), and remains a possibility if a balance shaft is to be avoided, even though the simultaneous ignitions from a common pin crank might end in disaster.


If I could get at the AES file once the car is added to the game, I could confirm the firing order easily.

Dear lord, now that is an absurd amount of knowledge that you're sharing with us, Griff. It's a bit daunting to read, to be truthfully honest, but nevertheless it's a great insight into the way the V10 engine functions. It's always a good thing that you are able to share all this with us lot, and I commend you on that. 👍

And you brought something really interesting too; this car is naturally aspirated. This much perfomance and not a single turbo? It's mind-boggling stuff to be sure...

 

[Vic Reign93]

Dear lord, now that is an absurd amount of knowledge that you're sharing with us, Griff. It's a bit daunting to read, to be truthfully honest, but nevertheless it's a great insight into the way the V10 engine functions. It's always a good thing that you are able to share all this with us lot, and I commend you on that. 👍

And you brought something really interesting too; this car is naturally aspirated. This much perfomance and not a single turbo? It's mind-boggling stuff to be sure...

It is mind boggling for sure, but considering the F1 3.5 V10s were making near 1000hp at their peak, I'm pretty sure an engine with double the displacement and with advances in engine technology could actually make that power if there was a reason to build such a monstrous engine.

Of course I'm very likely over-simplifying it all, but a guy can dream right?

I'll happily use 'Project X' to beat my long standing speed record of 342 MPH set by a Corvette C7 Prototype ( it was set early on in the games life when aerodynamic drag wasn't as strong. ).

 

[TexRex]