Anyone got a 9psi Harrop 112 pulley kicking around?

Anyone got a 9psi Harrop 112 pulley kicking around?

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Discussion

Boosted Cerb

Original Poster:

556 posts

237 months

Monday 20th June 2022
quotequote all
Hi Everyone,

Looking for a 9psi (80mm) pulley to go on my Harrop 112 blower. Sort of thing some of the old guard might have in the top of their tool box??

Been running the 12psi (75mm) pulley for years with std crank pulley but recently installed 8” crank pulley. Although car now boost 10psi in mid range, it’s now 3psi at the read line.

Previously it would hold 8psi throughout, so I’m now over speeding the blower. I put the original 85mm pulley back on and it holds a consistent 5psi so hoping 80mm is a sweet spot.

Could put the original crank pulley back on but it’s such a work up on my car.

Rich

Edited by Boosted Cerb on Monday 20th June 09:42

impVXR888

98 posts

128 months

Saturday 2nd July 2022
quotequote all
Hi, what you are seeing is massive belt slip. Due to the belt slip that’s causing the loss in boost. If you were overspinning the blower you’d not see a boost drop.
It maybe that you need a smaller belt length, also check the condition of the rear belt, may need replacing and rear tensioning.

Boosted Cerb said:
Hi Everyone,

Looking for a 9psi (80mm) pulley to go on my Harrop 112 blower. Sort of thing some of the old guard might have in the top of their tool box??

Been running the 12psi (75mm) pulley for years with std crank pulley but recently installed 8” crank pulley. Although car now boost 10psi in mid range, it’s now 3psi at the read line.

Previously it would hold 8psi throughout, so I’m now over speeding the blower. I put the original 85mm pulley back on and it holds a consistent 5psi so hoping 80mm is a sweet spot.

Could put the original crank pulley back on but it’s such a work up on my car.

Rich

Edited by Boosted Cerb on Monday 20th June 09:42