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What to do about a knackered exhaust valve?

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NEWCAR2025
Posts: 23
Joined: Mon Feb 02, 2026 8:33 pm

Good afternoon,

It was inevitable, I suppose....


My automobile abruptly lost power by around one-third when I was out for a "spirited" drive a few days ago. As the engine hp data readings increase over 390 hp, it's clear that there are no rough running or misfires, only a decrease in power.

Today I was able to get it into the Indianapolis 500 I had picked and onto STAR (thank goodness everything are back to normal now), and they have verified that one of the rear valves occasionally sticks. Even though it's a silencer part—which I unfortunately took off my car—it serves no use.

So, I'm wondering, what do I have to work with? It appears like I have two options: either have'someone' map out the valves or get a Stage 1 tune (I'm leaning toward MSL after hearing so many nice things about them), but I might be mistaken. Please, someone, teach me. :)

I really was hoping this wouldn't affect me, particularly this year because 2026 is going to be a very expensive year for me. However, my wife could use it as an excuse to get it tuned, which would strengthen our case for creating an even more extreme vehicle.

While I hope this doesn't happen again for a long, I would really appreciate any advise you can provide.

Much obliged
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LeeStu
Posts: 26
Joined: Mon Feb 02, 2026 8:29 pm

If what you say is true and the vehicle's valves and wiring are still there, then maybe an exhaust valve controller might be used to regulate them without the car having to sense their position? Same as Renntech or any other EVM.

It is fairly unusual for them to seize, so you might try servicing the valves to unstick it.
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NEWCAR2025
Posts: 23
Joined: Mon Feb 02, 2026 8:33 pm

I agree. I was wondering whether a pair of the valve deletion modules would be suitable for my needs. Simply put, you won't be getting your money's worth out of a valve controller.

However, other from the A35/A45 figment, I was able to locate all other delete modules.
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davejacobs
Posts: 37
Joined: Mon Feb 02, 2026 8:34 pm

I thought you were Imran? was in charge of exhaust?

Much obliged.
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NEWCAR2025
Posts: 23
Joined: Mon Feb 02, 2026 8:33 pm

It was reported a while back that he was gravely hurt in a vehicle accident. They temporarily removed that individual from the company, albeit I may be mistaken. However, I may be totally mistaken because I am not familiar with the firm at all.
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NEWCAR2025
Posts: 23
Joined: Mon Feb 02, 2026 8:33 pm

I noticed that ZAC Motorsport offers a valve remote code-out service when conducting some research on the subject:
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NEWCAR2025
Posts: 23
Joined: Mon Feb 02, 2026 8:33 pm

https://www.zacmotorsport.co.uk/product ... 026c11dd86
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NEWCAR2025
Posts: 23
Joined: Mon Feb 02, 2026 8:33 pm

Are there any comments or experiences on the'safety' of this procedure? Has anyone ever tried it? Seems quite simple to me....
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