Since my bud just went through the excruciating analysis of the Vette before buying one - I have been looking for info on the 5.0 Supercharged motors. I can't find alot out there. Where is a good place to see all the technical details about this powertrain? Things like induction, exhaust, inter-cooler design, boost pressure, cooling capacity analysis, transmission coolers, engine oil coolers, etc. Are there some good resources out there? Are there good discussions regarding some of the design compromises that may be risk areas? Thanks all.

BTW - the new Z06 (6.2 SC) is really full of issues for tracking. They really compromised on cooling. There's now a class action suit against GM for how it can't hold up on the track in hot temps; after a few laps the ECU really cuts back. All the automatic transmissions have cooling issues as well.

 

That is not information often published. You may be able to scrounge up some of it, but the OEM certainly isn't going to publish any information about possible downfalls in their design, and we don't really have the volume for any significant research into these areas yet. It is still a relatively new and unmolested platform.

 

Quite a lot of info about the AJ133 5.0 SC in the 2010 - 2011 XFR Workshop Manual, starting at page 844.
It's the exact same engine as in the F-Type R, just a lower tune version (510 PS vs 550 PS).
You can download the Workshop Manual from my Dropbox here: https://www.dropbox.com/s/bet26xniua...kshop.pdf?dl=0

 

Thanks, both. Yes, I have noted some older publications. I realize that they are of the same engine. I'd really like to find details on inter-coolers and cooling (i.e. air flow, radiators, and accessory coolers). These details are often platform specific or platform varied due to the packaging needs. Also, as they push the tunes up (e.g. SVR) they place higher demands on everything. ZF has data on AWD, however I know there are torque limits close to our rating at stock output. I wonder how that is managed and what we are doing to stress the transmissions when we start tuning further upward.
OzXFR - is there possibly one of these manuals out there on our cars?

 

Nothing on engines, but you might find it interesting to peruse my Dropbox folder, where I've collected as many F-type docs as I can find. Most are for MY14, but good info on 8-speed transmission, suspension, brakes, etc.
https://www.dropbox.com/sh/wgv3e86yc...glFoM3xOa?dl=0

 

Quite the collection of docs - THANKS! Great resources.

 

The trans in our car is rated for 700hp/700tq, and I believe only one person has come close to those numbers yet. ZF also offers a 900hp/1000tq option that should package the same if upgrades are needed. The real concern is the AWD unit; I have no idea how strong this is and it could be a major weak point. That being said, the GTR uses the same style system and they make monster power, so this may be something we can fix if it is an issue.

 

As a point of information, Horsepower varies as a function of torque and RPM; the proper way to rate the stress limit in gearing and transmissions is torque.

The research I had done earlier showed that we have the ZF8HP 'QuickShift' transmission. For that transmission I found that the ratings are not ft.lbs - but in NM (700 NM), which equates to approximately 516 ft. lbs. The standard R has a peak torque output of 502 ft. lbs.

This makes sense, since to have something much more capable would simply add unnecessary weight and cost to the vehicle. They don't build much margin in the packages anymore - especially when you are way up there in performance.

 

According to the Jag website, the SVR produces 516 lb-ft of torque. I doubt that Jag (or any manufacturer) would use a trans at its max. torque rating, so something doesn't add up.

I'm not questioning your research (a quick check of Wiki shows essentially the same thing). I wonder if instead of 8HP70, it is really 8HP75 which is rated at 553 lb-ft.

 

I certainly agree with you there. Who knows what the real rating is; ZF has typically been resistant to messing with their off the shelf options regardless of OEM. You get what they offer and nothing else, but maybe they made an exception for Jag like they did for FCA and we have a slightly updated transmission.

That being said we do know Jaguar has torque limiters built into the calibration that even the tuners can't get past, so perhaps that is in effort to save the transmission.

For example: launching off idle seems to be the quickest way to launch the V8, which would seem counter intuitive. If you load up the driveline to ~2000rpm, you'll actually get a slower 0-60 time in most cases. This is an example of the torque limiters under certain situations I believe.

 

To add to the mix, Jag's website claims that the FTR makes 502 lb-ft. According to Stuart@velocity their tune adds ~61 lb-ft w/o a pulley which puts it well beyond the spec for 8HP70 and some above 8HP75. I'm not impugning Stuart, just saying that something doesn't add up. And plenty of people have used Stuart's tune with no trans problems.

Not enough facts to come to any conclusion. Among the possibilities are that I'm not interpreting the specs correctly or our V8 cars really have 8HP90 which are rated at 900 nm (664 lb-ft).

Depending on which trans our V8 cars actually have, a tune could not only void the engine warranty, but the trans warranty as well.

 

Look up the Alfa Romeo 147GTA. They had to recall all of them and fit a new differential...

 

I'm willing to bet that the SVR limit of 516 is no coincidence with the 8HPO70 rating - likely they limited it there to continue using that transmission. I don't believe any of the manufacturers design "margin" into their products if it impacts CAFE or profit.

Remember Stuart always qualifies that dyno results vary significantly from machine to machine, tester to tester. The smart way of viewing the performance of his mods is to baseline run (ignore the absolute numbers), then run the modified tunes. The delta between baseline (stock) and modified is the delta. Assume the published numbers from Jag are the correct (OEM stock) numbers, then add that delta to be representative of what his tune does.

 

Oh they sure do! I would bet anything every trans they make can handle 10-15% more power than they claim. If jaguar was truly maxing out this trans, the chance of failures would go way up and when failures do occur ZF has to pay a substantial portion of the warranty cost. Every supplier part works this way. Under-rating their transmissions is as much a quality measure for them as it is for anything else, especially when they can upsell you on a higher rated transmission.

Another example is the 276 hp gentlemans agreement for Japanese cars in the late 90s/early 00s. The Skyline made wayyyy more than 276.

Ive got some friends in the trans. group and we use the exact same transmissions. I'll see what I can learn next week.

 

To my point - sorry I should have clarified - the car manufacturer (Jag) rides on the component manufacturer's margin (ZF) and doesn't build more in.

Being a retired licensed PE, however I disagree with you on "maxing out" and subsequently "failures would go way up". True engineers design and clearly clarify the operating environment with the customer to make sure the design bounds the use. Stress and fatigue were figured out a long, long time ago. As long as the customer properly identifies the service demands and the manufacturer does the proper analysis - all is well. This, of course, assumes we are talking about tried and true conventional designs and materials. Once you go off into new technologies, the uncertainties and margin significantly drop (e.g. aerospace, etc.).

 

DJS's dropbox is a wealth of info for anyone interested. Does anyone else have information on intercoolers? Radiator? Auxiliary coolers?

 

The claimed torque limits placed on transmissions factor in substantial abuse (shock loading) by the consumer. We have at least one data point to demonstrate that the ZF S6-45 tranny, rated at 347 lb-ft, can withstand 425+ lb-ft if the driver can refrain from dropping the clutch at full throttle.

 

Certainly more than one data point. The BMW guys regularly make 500+ lb-ft with the same manual trans.

 

Of course mechanical designs are virtually always built to handle more than the spec sheet says, but what really matters is the warranty. If the ZF trans is warranted to handle X lb-ft of torque but can actually handle 1.15X a vehicle mfg had better only connect an engine with X lb-ft of torque else ZF will likely deny warranty claims. But we really don't know what the specs on the web for our trannys means. Does it mean that it will xmit the torque into a high friction output (like dumping the clutch) or does it mean that it will xmit torque into a low friction output (like nailing it at 50 mph)?

This is exactly what we need to understand the specs. Thanks for doing this.