The one I got from G Force was an oval shape. The photograph of the Diamond tuner is rectangular.
One of life’s mysteries.
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Funny story about 260 tuner , I helped Paul Helton with his 1400 modified boat in 1992 he complained about a funny noise coming from gear case area , after checking seals finding nothing this was the first race of the season , he went on to win high points championship that year , the last race of the season Desided to drop gear case and let Phillip Bond go through it low and behold dropped gear case and tuner fell out it was best to hell and back but we came to conclusion it had been dislodged and off since 1st race !!! Go figure !!!!
Tuners on a Merc 2.5 DO make a difference. On boat telemetry shows it clearly.
Help from above, keep the velocity up. On our outlaw boat a tuner laying on the gearcase cost 1.4 tenths in 60’. Made about 100 MORE rpm up top. Put the tuner back and the ET drops to where is is supposed to be and the back door RPM drops as well.
It's probably in the single digit range and at this point weather data becomes a factor
roughly speaking 1% for every Kpa up or down and 1% for every 10 dgr celsius or atleast that is what my land and sea dyno software shows when i play with the weather data
So trying to do this on the water will need some care creating the same conditions
The tuner I’m using is oval with one shorter pipe and is kicked back slightly and welded to the plate. It came out of Larry Smith’s old yellow Triad (Mercury’s poster child, I used to call it). I showed Marty a picture of it a few years back when they were building my motor and he said it looked like it could’ve been one of theirs. I seem to recall seeing a rectangular G-force tuner somewhere in the past too?:confused:
I had it sandblasted and coated with a ceramic thermal coating and dry stacked it with two tiny pee holes in the tubes to spray the water pump.
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If I was looking for a new plate and tuner, I would give Geiger a call. Note that his pipes aren’t stepped and he says it makes the same power as the mercury F1 tuners. Go figure:
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I guess equal back pressure isn’t important? I do have a course with a timer system available. Over the years I have done plenty of testing on various modifications, but I never really have done any testing with tuners.
I don’t know much at all about them either, and what little I do know I’ve learned on these forums. Tuners aren’t really an easy part to swap out either, so most folks stick in what they think is best for their application and run with that.
I at least got one that had been run on a successful 2.5 Drag setup, so I just stuck with that. I have no idea whether I’m leaving 5hp on the table, and that’s not enough for me to care either, lol!
BUT, I do wish I had cut the snout on my mid like in the picture Chaz posted, just for cosmetic effect and probably better sound. I’ve seen that mod before on drag setups, including the Skywalker STV, which probably needed all the exhaust relief it could get when running on nitrous.
That backswept tuner would probably sound sweet at 10K+rpm too.
I don’t worry too much about tuners, if I need a little extra power I hit a button that injects some nice cool gas. :D:D:D
Brian. Geigertec seven 0 five - seven 1 eight - 0 one eight one.
He’s on Facebook, but can be hard to reach. The number circled on the screenshot below is his cell. You can call or text him at that number. I spoke to him the other day. Super cool guy but very busy.
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5 HP is five HP .. some don't seem to care what it costs .. :)
And like any good nitrous racer .. aim the jet assist to work in your favor .. :D
https://st.hotrod.com/uploads/sites/...dRonMuenks.jpg
https://i.imgur.com/Ta1xAXBl.jpg
Mach seyz :
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I did quite a search and couldn't find any info on Geiger, his tuners look so good that it would be a shame to put one inside a mid where no one could see it!
I agree with you .. thats why we put this one, where ya could see it ... :D
https://i.imgur.com/Ki7Sln7l.jpg
Yeah, 5hp across a good bit of the useable rpm band will make a difference.
I hear you on using the exhaust for thrust (or downforce, in the case of zoomies). Not sure my lil old 2.5 makes enough exhaust pressure to produce thrust, though.:nonod:
BTW: Me thinks that Camaro needs a couple of sizes less on fuel jetting. Need them candles lit blue…:rolleyes: