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Old 04-28-2011, 01:33 PM   #1
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Default 2860 Dyno - smaller housing swap will move tq to lower RPM ? yay or nay ?

Dyno graph from a BEGI Ramhorn tubular mani - GT2860RS with an .86- 12psi


Potential setup I may be buying for my stock VVT 2002.

If I were to swap the .86 for a .64 what will happen exactly ? From my limited knowledge it will move the torque and hp down about 500rpm earlier and sign off a tad sooner ? yay or nay ?

Since this dyno is in a 99 and I have a 02 with VVT will the graph look any different?

I'm asking as it seems to be a tad weaker than other setups when you look at the lower RPM figures.

Need advice - thanks.



BEGI Ramhorn tubular mani - GT2860RS with an .86
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Old 04-28-2011, 01:38 PM   #2
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probably something similar to the attached image:




how extreme of a change each side of the curve, I couldn't tell you.
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2860 Dyno - smaller housing swap will move tq to lower RPM ? yay or nay ?-ar_change.jpg  
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Old 04-28-2011, 01:51 PM   #3
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Awesome thanks.


Will a VVT equipped car change anything at all really in that curve vs. a 99 ?? Keeping the same .86 housing
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Old 04-28-2011, 01:54 PM   #4
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probably best of both worlds.
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Old 04-28-2011, 02:21 PM   #5
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I'd try the vvt with current hotside and see how you like that before going to the .64

What kinda fuel targets are you hitting and what does your spark map look like?
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Old 04-28-2011, 02:27 PM   #6
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I will barely be able to afford the 2860 setup as is so I wont be able to change anything......

If I do end up getting it I'll have to leave it alone and sell pop cans for gas money!

Sounds as if it will be fine at spooling and meet most of my needs compared to my failing 2560.....


I haven't aquired it yet (if at all) so I have no maps to share. If I get it I will definately report in detail.
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Old 04-28-2011, 02:29 PM   #7
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Are you thinking of buying Pat's setup?

I was there when he dynoed it, I wouldn't change it out.
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Old 04-28-2011, 02:33 PM   #8
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Yes I think that's his first name, not 100% sure. (pschmidt)



I'd be running it on my stock motor, any comments ?
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Old 04-28-2011, 02:38 PM   #9
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I think that setup is nice. I'd run it as is too
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Old 04-28-2011, 02:44 PM   #10
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Shhh, don't let the good word out. I have to work overtime in the mines and risk the black lung just to give him a lower offer. Word gets out and he'll tilt back in his chair, adjust his monocle and gesture his hand away away with you and I'm done ......

I'm hoping this all comes together, were still stuck on either 2 pigs and a donkey with the turbo kit or free passes to Euro Disney.......it's kind of a stalemate right now...
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Old 04-28-2011, 03:02 PM   #11
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I believe RHarris ran the .64 housing and saw much lower numbers and did not see a "shift left" for torque.

This a log manifold with a .86 housing from my car:

The car was very drivable, and I had zero desire to get a smaller turbine housing. You're going to make better low-end numbers with the tubular housing.

I'm not an engineer, but I know there is a trade-off between turbine AR, spark angle, and back-pressure. It looks like the bigger housing let me run more spark angle down low, which makes the car more drivable and reduces the "hump" in output when the turbo hit's prime flow rate. Coming from a guy with a tubular manifold and .86 turbine housing, leave what you have.
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Old 04-28-2011, 03:10 PM   #12
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Thanks for the info. - I love this site/place !

I'm already bench driving in my head down some of my favorite roads, getting excited............(for something that could still be weeks away!)
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Old 04-28-2011, 03:10 PM   #13
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I had a 2560 previously. I am now using a 2871 with 0.86 hotside and do not regret the trade off in spool. At the same boost level, I am probably 500-750rpms slower to target boost. Pretty sure the 2860 will be acceptable.

I have VVT, but it's not enabled...yet
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Old 04-28-2011, 03:12 PM   #14
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Keep the .86 as it comes as the .64 is too small and tops out too low. If I did it again, I wouldn't hesitate to go with a .86.
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Old 04-28-2011, 03:20 PM   #15
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Quote:
Originally Posted by dgmorr View Post
I had a 2560 previously. I am now using a 2871 with 0.86 hotside and do not regret the trade off in spool. At the same boost level, I am probably 500-750rpms slower to target boost. Pretty sure the 2860 will be acceptable.

I have VVT, but it's not enabled...yet

Are you still Adaptronic, I thought it supported VVT?


Let me know how it feels with VVT once you get it ?
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Old 04-28-2011, 06:13 PM   #16
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Quote:
Originally Posted by Landrew View Post
Are you still Adaptronic, I thought it supported VVT?


Let me know how it feels with VVT once you get it ?
I'll show your girlfriend how it feels to "get it".
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Old 04-28-2011, 06:16 PM   #17
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You got into the sugar again didn't you Walter.............
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Old 04-28-2011, 06:27 PM   #18
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Quote:
Originally Posted by Landrew View Post
Shhh, don't let the good word out.
*Ahem*

I'm not ignoring your PM, just haven't been able to drag my *** down to the mailroom.

At the time I dyno'd the car I was proud of that graph. It was my first RWD car so as long as the rear end was breaking lose I thought it was the fastest thing on the planet. I wish I could find the spark map I was using so we could all have a good laugh, as I added about 12 degrees of timing in throughout the midrange and picked up a crap ton of torque after that day. Of course, I'm cheap and never re-dyno'd but rather used the dragstrip to gauge my power increases.

The point is, with an optimized spark map you're going to make that graph look like rookie ****. Throw in the VVT and it's game over.
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Old 04-28-2011, 06:35 PM   #19
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That setup kind of stinks and will be slow and not really what I was looking for but I guess I'll buy it as a favour to you, "He said trying to sound carefree and not show any enthusiasm and give his secret desires away so the seller would take his offer"




Ahem back at you!


I thought you'd find this. I also thought after looking at other dyno's that there must be more in it. Looks like there is !! I mean if your into that kind of thing. I'm buying it for my sick dogs uncles cousin as a present - I could care less.

Sell it to me, sell it to me.......
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Old 04-28-2011, 08:13 PM   #20
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Landrew you are a funny guy.
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