Re: Young Performance 750- Latest engine
 

Just curious why some people don't use marine headers to dyno? Will it make a difference in HP?

Re: Young Performance 750- Latest engine
 

yes

Re: Young Performance 750- Latest engine
 

using the probes in each cylinder and the 02 sensor would be much more difficult....

Re: Young Performance 750- Latest engine
 

Customryder,
Also, a lot of motors use a lot of different headers and you can't go drilling holes in all of them because they are so expensive. Sean H is right, it makes the O2 sensor and the EGT probes difficult. I try to tune for the wet exhaust on the dyno. Every motor will get rich when you put it in the boat and add the water to the exhaust. The place that the water enters the exhaust stream will make a huge difference in both the hp change and the air fuel ratio change. If it enters at the end of the tailpipe, there won't be much loss if any in hp.
Also, the majority of dynos can't accept wet exhaust. They have mufflers that can't have water run through them. Hope this helps.

Re: Young Performance 750- Latest engine
 

Thanks for the info... so you if I understand correctly you make them a tad lean on the dyno? I know its hard to nail it on the dyno with the variances in the boat.. do you often half to make changes once they are installed in the boat?

Re: Young Performance 750- Latest engine
 

Not exactly. and yes minor changes may need to be made in the boat.

Re: Young Performance 750- Latest engine
 

We use all marine headers on our dyno. We run dry tail pipes so we don't fill our exhaust silencer system outside.

Re: Young Performance 750- Latest engine
 

Customryder,
Generally speaking, if you tune a motor perfectly on the dyno, it will be rich in the boat, with the addition of wet exhaust, and need to be touched up. That is why I shoot to have the motor a little lean on the dyno. That does not mean it will make more power. Actually, sometimes they make less. I am not tuning for the biggest hp number, but for the best in the boat with whatever exhaust it has.
Depending on the exhaust, I have seen the air/fuel ratio change over 1 point. That can make the difference between a motor being too lean on the dyno and too rich in the boat.
For the above reasons, I like to personally run each and every boat that has my motors. If I build a motor for Nortech or Hustler, for example, they will install it and I will fly to the factory and be present when the boat is ready to run for the first time. I do this for every motor that I sell. Hope this helps, Eddie

Re: Young Performance 750- Latest engine
 

Man and I thought you were a playa!!!! :drink:

Re: Young Performance 750- Latest engine
 

I think he's just skeered!!! :D :D