Wide Open Throttle??? How long can you hold her open in your 2 stroke turbo or BB??

snowmanx · Jan 17, 2008

On my 1150 about 45 seconds is pushing the limit... bore is so big the heat just keeps on building so I have to "blip" the throttle.

Are the 800 turbos any better??? Can you hold them WOT without any worries???

Debating whether I want to keep my "paid for" BB or buy a 2 stroke turbo.

Thanks for any input!

H2SNOW · Jan 17, 2008

probably till she blows
stick a primer on it when it starts to build heat giver 2-3 squirts ...egts come right down..

snowmanx · Jan 17, 2008

So how about you turbo guys....not as good??

Spaarky · Jan 17, 2008

I'm a little confused, if its jetted properly, why cant you just rip it for as long as you want....

Twister and I were talking about his turbo set up the other day, and he will hold it wide open all day long if he could....

snowmanx · Jan 17, 2008

Increasing temps.

Outlaw Addict said:
I'm a little confused, if its jetted properly, why cant you just rip it for as long as you want....

Twister and I were talking about his turbo set up the other day, and he will hold it wide open all day long if he could....

The longer you hold it wide open the hotter the egts get....it just continues to build heat I guess. I talked to Jeff at Dakota Performance about this and he told me what I've already stated, the bore is so large that it just doesn't keep the piston cool.

Water temps don't rise, they stay about 125*, so I don't know what to tell ya.

I run 1/4 AV gas, and have went all the up to full AV to see if that makes a difference, but to be honest I didn't even see any cooler EGTs that people boast about when using AV.

I've jetted up from 450 mains, what Jeff recommended, to 470s, with external jets screws turned all the way out, and it really doesn't make much of a difference at all.

If I'm doing something wrong, or got my facts screwed up, please explain. This is what I got from Jeff and if anybody knows there stuff, it's him. Unless I misunderstood him, but I don't think so.

modsledr · Jan 17, 2008

What compression ratio?
Are you running the advanced timing key?
What Pipes?

On my Union Bay 1150 i had the same issue. We dropped the compression ratio to 12.5:1. Installed the stock timing key. I run CrankShop twins in my Rev, but ideally the Jaws D stampings are the best (large volume pipes).

Now i can hold er open for pretty much as long as I want.

modsledr

snowmanx · Jan 17, 2008

modsledr said:
What compression ratio?
Are you running the advanced timing key?
What Pipes?

On my Union Bay 1150 i had the same issue. We dropped the compression ratio to 12.5:1. Installed the stock timing key. I run CrankShop twins in my Rev, but ideally the Jaws D stampings are the best (large volume pipes).

Now i can hold er open for pretty much as long as I want.

modsledr

I'm running the high compression heads, haven't taken the time to find out exactly what ratio.

You did remind though, I'm running the 4 degree advance timing key, I was thinking about going to the 2 degree to see how that changes things up...not sure how much HP you lose doing that, or even going to the stock key???

modsledr · Jan 17, 2008

These engines make great HP on the dyno with the high comp domes and advanced timing.

On the hill, if you want it to live, drop the timing. I only had the 2 degree advance key and 13.5:1 domes and was squeeking on long pulls.

Now, with the stock key and lower compression, hardly notice a diff in power and can hold 'er open and not hold my breath.

Dyno numbers help sales, but dont help you on the hill if cant ride how you want.

modsledr

modsledr · Jan 17, 2008

What Pipes?

If not the Jaws, you at least need to check the outlet diameter. If too small, that will also contribute to heat build up.

modsledr

snowmanx · Jan 17, 2008

Modsledr

You are so right about not being able to ride how you want and holding your breath! LOL

I think I will try the stock key....any long pull always seems like Russian roulette... I've help it open for as long as 1 minute, but it's scary!! Haven't squeeked it in the 2 1/2 years that I've owned it so I guess I've been lucky.

up-high · Jan 17, 2008

I found it amazing how a shot of nitrous would cool the egts and the water temp on my 700. Maybe you need to run some n2o(just for cooling of course!):beer;

kost-a-bunch · Jan 18, 2008

if you take away timing it will throw more heat in the pipe and egts will rise, open up the stinger ends to the next size of pipe to let out some pipe heat, like the other guy above^^^^ stated.
big bores need timing.

Ted
www.terraalpsracing.com

Spaarky · Jan 18, 2008

I talked to Jeff at Dakota Performance

nuff said there, that guy is the man!!!!! That motor wouldnt run half as good, without his touch.

I wondered if you were jetted to rich and dumping fuel in the pipe, building heat. Heck, I dont prolly know half what the other two guys replying do, so dont listen to me... .hahahahahahahahah

One thing, I cant believe is that Jeff hasnt figured out a fix for this, he's on top of stuff. Maybe there really isnt, I dont know.

CoyoteGirl · Jan 18, 2008

It would appear that our 2 1150's are much happier without the timing key. I haven't timed it yet, but I'm holding my sled WO alot longer this year than I did last year. And in fact, my EGTs quit on me for a few rides and I was ok with that. Last year on ANY climbs I was watching those buggers like a hawk so I knew when to get out of the throttle.

Brent has been through alot more learning as he bought the engine 2nd hand and had to work out the bugs. The stinger ends were definitely a problem. He had huge jets in there, but couldn't hold it WO for a 220 yd climb w/o losing a piston. Next thing he did was put the lower compression domes in there and then rode it w/o fear for the rest of the season.

This year, we took out the timing key after seeing some dyno runs w/ and w/o them. With the timing key it spiked alot, instead of a nice smooth curve.

So far I've got about 18 rides in on my sled this way and am loving it.

Do I feel a loss of HP, nope, she's still an arm stretching grunt machine. She's happy, I'm happy and neither of us are missing the few HP we lost by doing the lower compression domes and no timing key.

modsledr · Jan 18, 2008

One more thing to mention is that these big twins are all about torque. If you care about dyno HP numbers, buy a tripple. I seriously dont notice a difference in the mountains in power...if anything, its smoother and more responsive.

And like I said, no longer worry about holding 'er wide open on long climbs.

good luck...report back in how your changes work out.

modsledr

Red Dog · Jan 18, 2008

Both ya Brandy & Brent great response to this post, long Live the BB. Cheers Red Dog.:face-icon-small-coo

CoyoteGirl · Jan 19, 2008

Red Dog said:
Both ya Brandy & Brent great response to this post, long Live the BB. Cheers Red Dog.:face-icon-small-coo

HAHA, your BB was the most impressive thing I've ever seen. Woulda thought that sucker was a stock 4stroker!

Red Dog would hold his WO for MILES up at Whistler. Had me holding my breath, but she never let go! Whomever bought his engine is gonna be one happy bugger! :beer;

JStrows · Jan 19, 2008

why do you refer to sleds, engines, etc, as girls? I prefer the farm animal analogy. Pigs, cows.

modsledr · Jan 19, 2008

JStrows said:
I prefer farm animals. Pigs, cows.

I've heard that about you.

lol

JStrows · Jan 19, 2008

coming froma guy who admitted wearing womens panties....................? On the bright side, my sled ran like a scalded dog yesterday

Wide Open Throttle??? How long can you hold her open in your 2 stroke turbo or BB??

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