Holley TB secondary linkage change. Affect tune

General Tuning Questions And Discussions
Post Reply
Mr DOHC
Posts: 95
Joined: Wed May 18, 2016 4:34 pm
cars: VP Maloo

Holley TB secondary linkage change. Affect tune

Post by Mr DOHC »

Tuning question. I’m running a Holley 4150 throttle body on a dual plane manifold, and it came with the progressive linkages installed. The car is tuned, if I move to the 1:1 linkage, will that require a tune change?

I don’t think it will because, for example, in the VE map it’ll move from 1600rpm and 60VE to say 1600 and 80, because the increased air will just move it up the VE map won’t it.
And that area is tuned so no issue?
immortality
Posts: 3390
Joined: Thu Apr 09, 2009 12:31 pm
cars: VH, VN, VS, VX

Re: Holley TB secondary linkage change. Affect tune

Post by immortality »

Will probably make the throttle very touchy and a pain to drive.
Mr DOHC
Posts: 95
Joined: Wed May 18, 2016 4:34 pm
cars: VP Maloo

Re: Holley TB secondary linkage change. Affect tune

Post by Mr DOHC »

Yeah the kit gives you all 3 options.
The TBs come with progressive, then you can buy super progressive and 1:1

I can try all 3 and see what I like best
VK_3800
Posts: 523
Joined: Sun Jul 04, 2010 3:15 pm
cars: SS Torana
Location: NZ

Re: Holley TB secondary linkage change. Affect tune

Post by VK_3800 »

If you're referring to what Holley calls a progressive linkage, I think that just delays opening the secondaries?

Mine has that and I've still been chasing more progression on the primary opening (before the secondary even starts) to reduce the touchy throttle, hate to think how it would behave if all four opened at the same time.
Image

The tune can be affected as the TPS reading is linear but obviously you're changing the actual rate of opening area. Generally not too big a deal though.
User avatar
vlad01
Posts: 7749
Joined: Mon Oct 08, 2012 6:41 pm
cars: VP I S
VP I executive
VP II executive
VP II executive #2
VR II executive
Location: Kyneton, Vic

Re: Holley TB secondary linkage change. Affect tune

Post by vlad01 »

VE and all that won't be affected but depending if it's bad enough, you may have to adjust the AE multiplier table to account for the initial air in rush lean out/burst knock. Larger throttles/more linear needs more AE typically. Even if you get a lean spike on the WB, if it doesn't stumble or have burst knock then you can leave it as is, if it does, then increase the AE for the corresponding RPM range.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.
Mr DOHC
Posts: 95
Joined: Wed May 18, 2016 4:34 pm
cars: VP Maloo

Re: Holley TB secondary linkage change. Affect tune

Post by Mr DOHC »

quick update. the 1:1 was not good for my engine. way too much air too early. probably slowed down the air flow.
super progressive was no better or worse, just pointless.

Tune seemed to be unaffected.
Post Reply