One Daytona Blvd. Daytona Beach, FL 32114 P: +1 (386) 310-6500
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IMSA TECHNICAL BULLETIN IWSC #21-02
To: All IMSA WeatherTech Sportscar Championship LMP3 Participants
From: IMSA Competition
Date: November 20, 2020
Re: IWSC LMP3 2021 Daytona Technical Specifications
The contents of this Technical Bulletin are specific to the 2021 ROAR and Rolex 24 at Daytona and the IWSC LMP3 class. It does not apply to future IWSC LMP3 Events.
With regards to the Clutch, Entrants are permitted to either:
A) Update VK56/VK50+ powertrain to the Clutch EVO kit as detailed in the attached ORECATechnical Bulletin
B) Use the homologated VK56/VK50+ clutch kit
No other clutch kit specifications are permitted.
With regards to the Exhaust, Entrants are permitted to either:
A) Update VK56/VK50+ exhaust manifolds with a Zircotec coating as detailed in the attachedORECA Technical Bulletin
B) Use the homologated VK56/VK50+ exhaust as homologated and delivered
No other exhaust treatments or specifications are permitted.
No other endurance related modifications to the vehicle are permitted.
LMP3 VK56/VK50+ GIRARD Stéphane
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Dear ACO / IMSA / LMP3 competitors,
Following the identified need of a longer life expectancy clutch for long endurance races, like 12h or 24h, it has
been decided to propose a new clutch specification (Sachs 4 disks x 3.4mm 140mm diam all metallic).
Unfortunately, this clutch evolution in not “plug and play” and requires some assembly care / modification.
A “Clutch evo kit” is now available to order – see below the content of this kit
This clutch is compatible to either vk56 or vk50+ engine specification. It is only for DAYTONA 24h 2021 usage
until further notice.
1 – CLUTCH EVO KIT CONTENT:
The “Clutch evo kit” includes the following parts:
� 1 new Sachs 4 disks x 3.4mm 140mm diam. all metallic evo clutch (A)
� 1 new adapted flywheel (only flywheel side – not the starter ring) – with 8 new longer clutch studs
already mounted on it (B)
� 8 new Simmonds nuts for clutch mounting on flywheel (C)
� 8 new flywheel screws (D)
� 8 new starter ring screws (E)
� 3 cylindrical spacers for slave cylinder mounting (F)
� 1 new needle bearing for gearbox shaft centering in crankshaft (G)
VK56/VK50+ - Clutch evo kit for Daytona 24h 2021
A
B
D
C
E F
G
LMP3 VK56/VK50+ GIRARD Stéphane
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2 – ORDERING AND AVAILABILITY
� Ordering has to be done through our LMP3 spare parts official dealer in North America:
Att: Mr Greg WRZESINSKI – VP of Operations
CARL HAAS AUTOMOBILE IMPORT Inc
500 Tower Pkwy – LINCOLNSHIRE IL60069
� Reference to order is “LMP3 Cluth evo kit – Daytona 24h”.
� Ordering is open. We recommend you proceed ASAP.
� Delivery scheduled is early January 2021 in Haas Auto.
� Orders received by Haas Auto after 30th Nov. 2020 will be too late to guaranty early January delivery in
USA so on time for 24h Daytona race week
� Price will be defined by Haas Auto shortly as it should include all transportation and custom fees.
3 – ASSEMBLY PROCEDURE
� A complete assembly procedure is available and will be supplied to the teams ordering the kit.
4 – OLD PARTS REMAINING
At the end, customers will have to keep with them the following parts that have been replaced, in case they
want to revert to the old clutch specification:
� Sachs 3 disks 3.4mm 140 mm diam all metallic clutch
� The flywheel adapted to this clutch specification with its 8 clutch studs mounted on it.
� The spacer for the clutch slave cylinder assembly for this spec of clutch
CAREFUL: You must absolutely not mix both types of flywheel and clutch as they are not compatible !
Removed spacer
LMP3 VK56/VK50+ GIRARD Stéphane
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The new clutch once installed
Don’t hesitate to contact us in case of questions, using mail address below:
ORECA OFFICE ADRESS :
Technopole du Circuit
58470 Magny-Cours
FRANCE
Office : +33 (0) 386 210 800
ORECA LMP3 CONTACTS :
Email : [email protected]
LMP3 VK56/VK50+ GIRARD Stéphane
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Date: 18/11/2020
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Dear ACO / IMSA / LMP3 competitors,
Following the feedback of the first races of LMP3 - new generation, it has been identified that chassis parts / car
body could suffer long term from heat released by both exhaust manifolds. To protect those parts ahead of long
endurance races, like 12h or 24h, it has been decided to propose a coating specification that can be applied by
each LMP3 customers on their existing exhaust manifolds.
This coating application is compatible to either vk56 or vk50+ engine specification, as well as for brand new or
already run exhaust manifolds. It is only for DAYTONA 24h 2021 usage until further notice.
1 – COATING SPECIFICATION CHOICE:
Several approach for coating has been studied:
� Aeronautic style multi layers heat shields:
Very good efficiency as thermal barrier
Very expensive / better for turbocharged engines
Not enough space to accommodate on LMP3 car layout
Delay / schedule for production is after Daytona 24h
� Solution not recommended by ORECA for LMP3.
� Thermal barrier tape:
Very cheap and very short delay
Thin so no space problems for accommodation / flexible
Not very efficient (depend on how well wrapped)
Short life, get damaged / worn quickly
Retain inflammable fluids so can be dangerous!
� Solution not recommended by ORECA for LMP3.
� Ceramic sprayed coating:
Very thin layer so no space problems for accommodation
Good efficiency and life expectancy as thermal barrier
Well adapted to normally aspirated engines application
Can be applied to already run exhausts.
Reasonable delay for spraying process.
Reasonable cost.
� Solution recommended by ORECA for LMP3.
VK56/VK50+ - Exhaust manifolds coating recommendation
for Daytona 24h 2021
LMP3 VK56/VK50+ GIRARD Stéphane
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2 – RECOMMENDED PRODUCT AND SUPPLIER
Among the world of motorsport suppliers, with several suppliers able to apply such kind of coating, ORECA
would like to recommend one considered as a reference in mastering this product in terms of quality / efficiency
and capacity of process (speed / delay).
We would like to recommend ZIRCOTEC Ltd company:
ORECA Technology and ZIRCOTEC technical discussions have led to propose ZIRCOTEC PERFORMANCE WHITE
Thermal Barrier Coating as the most appropriate coating for the job, with a good value for money, to improve
the thermal protection of chassis parts under the bonnet.
Example of Zircotec Performance White thermal Barrier Coating
Technical description of the coating can be found in annex of this document.
LMP3 VK56/VK50+ GIRARD Stéphane
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3 – CONTACT IN ZIRCOTEC Ltd
� For more information regarding price / delay we recommend teams to contact on our behalf:
Mr Joe HARWOOD
Motorsport Sales Manager
ZIRCOTEC Ltd.
Innovation House
39-41 Nuffield Way
Abingdon – OX14 1RL
Oxfordshire - UK
Tel : +44 (0)1235 546 050
Mob : +44 (0) 7876 191 844
www.zircotec.com
� Standard delay for the spray application is 10 to 15 days
� Application has to be done on all primaries and 4 into 1
� Estimated price for a pair is below 1000£ “ex-works” w/o transportation and custom costs, exact price to
be confirmed with Zircotec directly.
� Application can be done on new or already run manifolds, for vk56 or vk50+ specifications
LMP3 vk56 exhaust manifolds
LMP3 VK56/VK50+ GIRARD Stéphane
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Date: 18/11/2020
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4 – EXTRA RECOMMENDATION
� ORECA recommend customers to liaise with their LMP3 chassis manufacturer to see if they want to
continue the coating application up to the end of the exhaust tail pipes.
Don’t hesitate to contact us in case of questions, using mail address below:
ORECA OFFICE ADRESS :
Technopole du Circuit
58470 Magny-Cours
FRANCE
Office : +33 (0) 386 210 800
ORECA LMP3 CONTACTS :
Email : [email protected]