IMSA DPi Discussion

[Accident]

Originally Posted by Coach Ep

Oreca is the current tuner/supplier for all the LMPC (Chevy, in the US) and LMP3 (Nissan, worldwide) engines, they would most likely be able to support a DPi project including engine supplies if the check is written to the right amount by a willing manufacturer.

I thought the LMPC LS3 engines were built by Katech? Did Oreca take it over in the last few years?

[HORNDAWG]

Originally Posted by Accident

I thought the LMPC LS3 engines were built by Katech? Did Oreca take it over in the last few years?

They come from Katech.

ARTICLE 7 –ENGINE
7.1 Engines must remain sealed and keep all the markings affixed by Katech, at all times, including when returning the engine to Katech for rebuild.

https://competitors.imsa.com/sites/d...c_20161216.pdf









L.P.

[canaglia]

Katech indeed, each car has katech sticker....

oreca tunes lada WTCC engines as well (at least, until last season it did)

[chernaudi]

Tech article about the Cadillac DPI engine:

http://www.enginelabs.com/news/cadil...ails-released/

[canaglia]

Originally Posted by chernaudi

Tech article about the Cadillac DPI engine:

http://www.enginelabs.com/news/cadil...ails-released/

Insane, no internal damages after daytona race (24H + >6H between Q and FP sessions). That engine is a tank, considering that it revs up to 7500rpm, unusual for so large motors.
Unfortunately can be never found a real equivalence between a 4L and a 6.2L, even if they push the same hp.

To set a 5.5L as max NA displacement won't be a bad idea.
IMSA should introduce a free layout as well, because if am I not wrong turbo engines can be only V6 or L4, and are not allowed V10 or V12 for NA.

[Matt]

V10's are allowed.

If a manufacture came to IMSA with a motor not within the current printed regs, and were gonna throw the money at it, they'll be allowed in.

[hondafan37]

Originally Posted by canaglia

Insane, no internal damages after daytona race (24H + >6H between Q and FP sessions). That engine is a tank, considering that it revs up to 7500rpm, unusual for so large motors.
Unfortunately can be never found a real equivalence between a 4L and a 6.2L, even if they push the same hp.

To set a 5.5L as max NA displacement won't be a bad idea.
IMSA should introduce a free layout as well, because if am I not wrong turbo engines can be only V6 or L4, and are not allowed V10 or V12 for NA.

NA V10 5.2L as max limit are allowed too.
http://mariantic.co.uk/lmp/DPI.asp

[Maelochs]

Originally Posted by hondafan37

NA V10 5.2L as max limit are allowed too.
http://mariantic.co.uk/lmp/DPI.asp

v it's almost like a special provision was written in for VAG's Lambo and Audi motor ... what a weird coincidence.

[YZFrider]

Thanks for posting that. Fascinating insight and now we know that engine isn't ad production as we once thought

[Maelochs]

Amazing how much more that engine has in it. They could probably add a couple hundred hp without losing much reliability just by lightening all the rotating mass and adding DI.

[canaglia]

good spot!
so IMSA updated engine rules to let audi/lamborghini step in DPi if they wish.
Such a shame that is a very unlikely scenario....

anyway SRT/dodge could be allowed as DPi manufacturer... if the cut 3L from their V10

[chernaudi]

600bhp reliably for a 24 hour race isn't really special though nowadays. Audi were doing that for years with the R8's engine going back to 1999. Judd were doing it with their 5/5.5 liter V10s with almost no failures back over a decade ago.

And the Gibson 4.2 liter V8s haven't had a mechanical failure all year, it's been all electronic junk. And it makes the same 600bhp as the Cadillac does from two less liters.

And also, it seems that GM did what Nissan did with the LMP2 spec version of the Nissan VK45 V8 (which was a de-tuned Super GT engine), and made as many modifications to it as the rules allowed.

Of course, those engines were developed by people who knew what they were doing and in the case of Audi Sport and GM, also had some cash to work with. Sadly until recently, AER couldn't say that about their sportscar racing engines. But what would one expect from a company that's partly owned by Dyson Racing and seems to have carried over their hot-rodder tendencies?

[canaglia]

Originally Posted by chernaudi

600bhp reliably for a 24 hour race isn't really special though nowadays. Audi were doing that for years with the R8's engine going back to 1999. Judd were doing it with their 5/5.5 liter V10s with almost no failures back over a decade ago.

And the Gibson 4.2 liter V8s haven't had a mechanical failure all year, it's been all electronic junk. And it makes the same 600bhp as the Cadillac does from two less liters.

And also, it seems that GM did what Nissan did with the LMP2 spec version of the Nissan VK45 V8 (which was a de-tuned Super GT engine), and made as many modifications to it as the rules allowed.

Yeah, but audi R8 V8 turbo and judd NA 5.0 -> 5.5 V10 are bespoke engine, cadillac dpi is a road derivated engine, it wasn't designed from stratch for racing.
LMP2 nissan engine was modified by zytek, that basically was a street engine tuned to be the most reliable possible. Infact, because of that, it has never been possible to have a huge power increase during the 2011-2016 lifespan because reliability and low cost maintenance were main goals to keep (about 450hp in 2011 to about 500hp in most recent years).

"And it makes the same 600bhp as the Cadillac does from two less liters"

to achieve high powers is simple... just make the engine rev as higher as possible. Hard part is to keep it reliable.
Anyway, it's just the eternal struggle between
dyno engine (big displacement, low rev, high torque release) vs. high rev engine (smaller displacement, high rev, low torque release)

[JHamilton]

Originally Posted by canaglia

good spot!
so IMSA updated engine rules to let audi/lamborghini step in DPi if they wish.
Such a shame that is a very unlikely scenario....

anyway SRT/dodge could be allowed as DPi manufacturer... if the cut 3L from their V10

Sadly, the Dodge V10 has gone to the big dyno in the sky. They do make some rowdy pushrod V8s in 5.7, 6.2, and 6.4L displacements... I hadn't even thought about Dodge doing a DPi, but that would be rad!

[chernaudi]

Originally Posted by canaglia

Yeah, but audi R8 V8 turbo and judd NA 5.0 -> 5.5 V10 are bespoke engine, cadillac dpi is a road derivated engine, it wasn't designed from stratch for racing.
LMP2 nissan engine was modified by zytek, that basically was a street engine tuned to be the most reliable possible. Infact, because of that, it has never been possible to have a huge power increase during the 2011-2016 lifespan because reliability and low cost maintenance were main goals to keep (about 450hp in 2011 to about 500hp in most recent years).

"And it makes the same 600bhp as the Cadillac does from two less liters"

to achieve high powers is simple... just make the engine rev as higher as possible. Hard part is to keep it reliable.
Anyway, it's just the eternal struggle between
dyno engine (big displacement, low rev, high torque release) vs. high rev engine (smaller displacement, high rev, low torque release)

You seem to be forgetting that when it was used in Super GT Nissan were getting over 500bhp out of the same engine, and dyno'd it to well over 800bhp.

NASCAR V8s are nowadays purpose built engines, but they still detonate at least one or two a race even today.

[Maelochs]

Originally Posted by chernaudi

NASCAR V8s are nowadays purpose built engines, but they still detonate at least one or two a race even today.

True ... but they race them at almost full throttle the whole race and make (I hear) like 900 bhp.

[Matt]

800/850 nowadays. Still north of 9k rpm.

[fieldodreams79]

And they sound terrific north of 9K, too, imho.

Staying on/off topic.

I looked up the LMP Panoz motors in Mike's corner and I never realized that they were a Zytek based V8s, serviced by Elan. I had always thought Robert Yates had something to do with it...

[HORNDAWG]

Ganassi, it seems, would like to go DPi racing ...

http://www.racer.com/imsa/item/14287...sa-dpi-program





L.P.

[fieldodreams79]

Originally Posted by HORNDAWG

Ganassi, it seems, would like to go DPi racing ...

http://www.racer.com/imsa/item/14287...sa-dpi-program





L.P.

On the latter mentioning of Dodge, i was thinking how cool it would be to have a Detroit Battle. If BOTH Ford and Chip are interested, maybe there's a chance....

[Bcarr6]

Originally Posted by HORNDAWG

Ganassi, it seems, would like to go DPi racing ...

http://www.racer.com/imsa/item/14287...sa-dpi-program





L.P.

That is one of those articles where the headline says one thing and the story says another

Basically- yeh it'd be nice but not now and ford arent interested currently

OR they are but don't want to show their hand yet


Sent from my iPhone using Tapatalk

[chernaudi]

Originally Posted by fieldodreams79

And they sound terrific north of 9K, too, imho.

Staying on/off topic.

I looked up the LMP Panoz motors in Mike's corner and I never realized that they were a Zytek based V8s, serviced by Elan. I had always thought Robert Yates had something to do with it...

The 6 liter pushrod V8 were Ford small block based and were built at various times by Roush, Yates, or by Panoz themselves (Elan's engine decision was basically founded by ex-Roush and Yates guys). Gibson made the EFI systems for it.

The 4 liter DOHC engine, though it was initially intended to be badged as a Ford engine (it never actually was), was designed by Gibson (then known as Zytek) and was based on their Formula 3000 engine that they designed with Judd, which was based on the Cosworth DFV.

Strangely, Gibson still retails the engine as the ZB/ZG408, as well as it's reduced capacity (3.4 ZG348) and enlarged (4.5 ZJ458) versions on their site. Even the 4.2 GK428 LMP2 engine probably owes much of it's heritage to the older Zytek V8s

[JHamilton]

Originally Posted by fieldodreams79

And they sound terrific north of 9K, too, imho.

Staying on/off topic.

I looked up the LMP Panoz motors in Mike's corner and I never realized that they were a Zytek based V8s, serviced by Elan. I had always thought Robert Yates had something to do with it...

That was the LMP07. The LMP-1 had a Elan Ford V8.

I think Yates built the V8s in R&S and others.

[hondafan37]

HPD President Art St Cyr pleased with first Acura ARX-05 DPi test.
The car had the first shakedown at Paul Ricard last week.

http://www.racer.com/imsa/item/14288...tes-first-test

[canaglia]

Originally Posted by chernaudi

You seem to be forgetting that when it was used in Super GT Nissan were getting over 500bhp out of the same engine, and dyno'd it to well over 800bhp.

NASCAR V8s are nowadays purpose built engines, but they still detonate at least one or two a race even today.

You're right, but repeat, in GT500 nismo tuners weren't aimed to make it last for >24H or keep it as cheap as possible to maintain.
That's why during early years in lmp2, 500hp weren't achievable.

As other users already reported, nascar engines run flat out at 9000rpm... it's quite reasonable that can't have an endurance style lifespan.
Corvette GTE engine runs up to 6500rpm, unrestricted could achieve >800hp too @ >8500rpm. For sure won't last more than 6 hours.