Exhaust tuner on 175 efi

[jgreen]

I hear that the only difference between the 175 and the 200 is the length of the tuner, the 200 is 6" shorter than the 175.

Would there be any benefiet to cut 9" of instead of 6" ?

[jgreen]

I hear that the only difference between the 175 and the 200 is the length of the tuner, the 200 is 6" shorter than the 175.

Would there be any benefiet to cut 9" of instead of 6" ?

[Mark]

I believe it is more than that. The 175 has smaller exhaust ports and a 14" tuner. The 200 has large exhaust ports and a 7 3/4" tuner. They also have differently calibrated ECUs. To raise HP, if you increase exhaust you need to also increase aspiration. From what I understand, if you cut the tuner you may gain a little on top end, but lose on hole shot as a result of lower back pressure. Do a search on S&F, they talk about this stuff constantly. There is very little agreement on this one. However most believe that cutting a tuner by itself, w/o other mods, will give you little to no gain.

[panther150]

I'm NO expert,but from what I've heard, the main difference is the porting, also,I heard the 150XR2 heads make a difference,but with todays "goat piss" gas, I would'nt change the compression if I could get enough performance with just changing the porting/tuner.My two cents.

[jkeiper]

Jeff:

The porting is different between the 175 and 200 that you have unless Randy changed it. That is why you don't get a 25hp gain by changing tuners. You will loose some bottom end so you don't want to go any shorter. You gain it back with setting the timing like a 200. (slightly more aggressive) When you get to the 2001+ motors the 175 and 200 porting is the same. Ithink they did that to save cost of having two blocks. The 150 however still has different porting.

Jim

[jgreen]

So would I be better off to just leave that alone since the porting is stock ?

[JW]

Be better to sell the 175 and get you a nice used 3.0 225 EFI http://www.checkmate-boats.com/graemlins/thumb.gif

[jkeiper]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">So would I be better off to just leave that alone since the porting is stock ? </div></BLOCKQUOTE>

No, but you won't get 25hp frm a tuner swap.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Be better to sell the 175 and get you a nice used 3.0 225 EFI

</div></BLOCKQUOTE>

Better yet. Get the 2100 Pulsare long deck you want and hang a 250xs on it. http://www.checkmate-boats.com/graemlins/thumb.gif

Jim