Hondata R&D finds limit of Civic CVT

Hondata

Hondata
Elite Sponsor
Joined
Nov 27, 2015
Threads
99
Messages
911
Reaction score
2,499
Location
Torrance California
Website
www.hondata.com
Vehicle(s)
23' Type R,22' Civic Si,18' Accord 2.0T,17' FK8
Vehicle Showcase
1
Country flag


Scored belt (below) at maximum torque.

Honda Civic 10th gen Hondata R&D finds limit of Civic CVT cvt-drive-belt-maximum-engine-torque-


Belt condition (below) after 6 hours of circuit racing at Miller Utah with Hondata 6 PSI reflash. As new!

Honda Civic 10th gen Hondata R&D finds limit of Civic CVT CVT drive belt after Miller 6 hour


How CVTs work:



For reference, here is our dyno chart from the CVT + 6 PSI tune. Our dyno is a little optimistic so our 220 lb-ft Dynapack torque is equivalent to around 200-205 lb-ft Dynojet torque at the wheels. Thats about a 15% increase over stock.

Honda Civic 10th gen Hondata R&D finds limit of Civic CVT 17_civic_cvt_stock_87_oct_vs_91_octane_plus_6_ps
 
Last edited:


OP
OP
Hondata

Hondata

Hondata
Elite Sponsor
Joined
Nov 27, 2015
Threads
99
Messages
911
Reaction score
2,499
Location
Torrance California
Website
www.hondata.com
Vehicle(s)
23' Type R,22' Civic Si,18' Accord 2.0T,17' FK8
Vehicle Showcase
1
Country flag
CVTs and automatic transmissions have a torque converter, which "slips" under varying circumstances. The same level of boost gives different levels of torque at different RPMs. So, we can't accurately specify PSI. Variables in this include transmission fluid temperature. The higher the transmission fluid temperature, the poorer the oil's lubrication and protection characteristics.
 

Design

Senior Member
Joined
Sep 28, 2015
Threads
28
Messages
3,329
Reaction score
2,903
Location
Southern California
Vehicle(s)
09 MS3, 17 ABM Si Sedan
Country flag
you can adjust the boost by the rpm. So could just add more boost after the peak tq to even out the TQ curve
Saw your edit... my thoughts as well. On the MS3, we saw a similar problem. But the weakest link was the rods. Extending boost to the upper RPM range reduced that stress (at the expense of the factory turbo).

@Hondata - Other thoughts on this issue? (Edit: NM, saw your post above).
 

360glitch

Moderator
Joined
Feb 15, 2017
Threads
108
Messages
4,710
Reaction score
4,875
Location
USA
Vehicle(s)
2019 Accord Sport 2.0T, 2017 Si Sedan (Sold), 2017 Sport Hatchback (Sold)
Vehicle Showcase
1
Country flag
So was a specific limit actually found? Was hoping for an estimated level of torque that the CVT could handle. Not really an issue for me, I am a 6MT guy but was curious.
 


OP
OP
Hondata

Hondata

Hondata
Elite Sponsor
Joined
Nov 27, 2015
Threads
99
Messages
911
Reaction score
2,499
Location
Torrance California
Website
www.hondata.com
Vehicle(s)
23' Type R,22' Civic Si,18' Accord 2.0T,17' FK8
Vehicle Showcase
1
Country flag
The data you are looking for would require an engine and transmission dyno. It would also require full control of the separate CVT computer. Honda Japan will have this information. A brief over-torque spike causing momentary slip is all that is needed to start the scoring on the belt. Once started, the CVT would transmit less and less torque as the scoring increased.
 

ichii

Senior Member
Joined
Feb 16, 2016
Threads
4
Messages
437
Reaction score
148
Location
PA
Vehicle(s)
2016 Civic coupe and 2011 CR-Z
Country flag
The data you are looking for would require an engine and transmission dyno. It would also require full control of the separate CVT computer. Honda Japan will have this information. A brief over-torque spike causing momentary slip is all that is needed to start the scoring on the belt. Once started, the CVT would transmit less and less torque as the scoring increased.
So would running it at the +6psi safe? Not issue with scoring the belt?
 

HondaPro

Senior Member
Joined
Oct 22, 2015
Threads
51
Messages
1,521
Reaction score
982
Location
Indiana
Vehicle(s)
2016 EXT Civic & 2017 Civic ExT
Vehicle Showcase
1
Country flag
So would it be safe to say you could achieve higher torque levels safely with a manual? And how much more?
 


 


Top