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Old 07-29-2009, 12:05 PM   #141
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I will never understand why a 71mm compressor has an outlet the size of my urethra. What is that, 30mm?

velocity? Garrett even publishes the A/R on the compressor outlet matters little.
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Old 07-29-2009, 12:15 PM   #142
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So it looks like the real solution to the stretching hardware is to replace with v-bands.
This is untested in a Miata, but I doubt anyone can make v-bands fail without being stupid.
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Old 07-29-2009, 12:18 PM   #143
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Ouch...ATP made you buy an entire turbo eh....returning the second housing or did you get the .64 with the turbo?
I guess he got the 2871 for cheap from egay or sumething... looks used.
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Old 07-29-2009, 12:24 PM   #144
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oh i missed the ATP drama, cliffnotes please!
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Old 07-29-2009, 01:11 PM   #145
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I guess he got the 2871 for cheap from egay or sumething... looks used.
Looks used? What is it, all that carbon build up in the exhaust outlet?

ATP made him buy a complete turbo, but they are taking back the exhaust housing he bought for mock-up.
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Old 07-29-2009, 01:52 PM   #146
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I guess he got the 2871 for cheap from egay or sumething... looks used.
I seem to be looking a different picture than you.
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Old 07-29-2009, 01:59 PM   #147
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oh i missed the ATP drama, cliffnotes please!
And they ship me one of their cheap standard 3" V-band flanges, which doesn't mate up to the tial housing. Sav had to go to ATP, verify the proper flange, and overnight-saturday delivery it to me.
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Old 07-29-2009, 02:12 PM   #148
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Wow, second site I've seen ~mid $800 "ramhorn" style manifolds. Maybe I should do one? They aren't as good as the standard Absurdflow, but are a lot easier to build and if some girls are willing to pay that, wow.
strong opinions there, especially for never having built one. more material, more cuts, stainless, unmatched welds, and fully backpurged. Those things cost money. They also flow better. Your design is good and unique, but it may not be as good as you think. The collector on that mani alone requires a lot of work.
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Old 07-29-2009, 02:37 PM   #149
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Yeah, ATP added $120 to their quote between the time I called for a price and the time I actually bought it. I bitched and moaned and the guy agreed to take the turbine housing I'd already bought back, AND not charge the 15% restocking fee. I considered just getting the .64 with the turbo but I have dyno time and a track day to pay for in the next 2 weeks.
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Old 07-29-2009, 02:43 PM   #150
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I don't see how Tim's manifold's collector could be improved.






short and sweet; the exhaust isn't taking a roller coaster ride before reaching the turbo. plus his wastegate placement is more ideal than most out there.
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Old 07-29-2009, 02:58 PM   #151
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pictures dont work

edit: nvm working now
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Old 07-29-2009, 03:10 PM   #152
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strong opinions there, especially for never having built one. more material, more cuts, stainless, unmatched welds, and fully backpurged. Those things cost money. They also flow better. Your design is good and unique, but it may not be as good as you think. The collector on that mani alone requires a lot of work.
1. I have to have a strong opinion!
2. How do you know I never built one?
3. More material? Yes. More cost there, more weight, more heat loss, less stiff.
4. More cuts? More STRAIGHT cuts, yes. Straight cuts are easy.
5. Unmatched welds/fully back purged? Debatable. I am not as pretty as a robot welder but I do know my welds are fully penetrated. Definitely a lot more welds to do on those manifolds, but welding is easier/more fun than grinding and fitting. Plus more welds=more chances one of those "fully back purged" welds cracking. Long runner manifolds like that do have harmonic issues on 4cyls. (actually everything does, but the longer the pipe, the worse it is)
6. Those things cost money? Sure do.
7. They flow better? I disagree. More bends & more length = more restriction. They may make more power in a very narrow window (i.e. cool for drag racers or dyno queens w/anti lag), but spool and overall "area under the curve" won't be close.
8. The collector on that mani alone requires a lot more work than my mani? No. You can purchase those collectors already done for not a lot of money. Or if you want to DIY, the straight cut that goes into making a 4-1 collector is significantly easier cause it's made on a straight pipe. ****, you could print out a paper template if you have a halfway decent CAD program, wrap it around the pipe & draw a line with a sharpie, then go to town with your band saw or cutoff wheel. Simple. Quick. Easy. If you screw up following your line, not a big deal. Sand flat with a belt sander. You're making the bends of the primaries mate up to the collector, so the angles don't need to be dead-nuts. Each pipe in my collector has to point exactly where it needs to be, not much room to fudge there.

Welding in between the 4 pipes, in the center of the collector, is a real PITA and worth a few hundred to do right there. But I never built one, right?

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I don't see how Tim's manifold's collector could be improved.






short and sweet. plus his wastegate placement is more ideal than most out there.
Thanks scott. Those pics show a little the effort that goes into it. If you're off a little on the angle of those cuts, you got to start over, so it takes time to do right. You can fudge it and fill in the gaps with welding rod if that's your thing.
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Old 07-29-2009, 03:11 PM   #153
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pictures dont work

edit: nvm working now
That happens to pics on my site. I have no idea why. Network Solutions doesn't know why either.
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Old 07-29-2009, 03:27 PM   #154
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Dunno if it has already been mentioned, but on Tim's manifold, aren't the exhaust pulses to the turbo going to be slightly off-beat? However, I do not know how much of a difference a few centimeters make.

Compare it to say, an S4 manifold. Is it better to have a short&sweet manifold with offset pulses or a 'roller coaster' path and synchronized pulses? (neglecting EWG for now)
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Old 07-29-2009, 03:37 PM   #155
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cuts are made right before or right after the start of the bend. by the middle of the bend all primaries are joined, 1 and 4 at close to 90 degrees. this is your typical merge collector like those used on full race manis:

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All primaries meet at a ~15 degree angle and contine a "straight" path

his wg placement is the norm, ideal would be a teardrop/heartshape cut at the collector with a bend like this

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granted his setup will work just fine. it's the guys with big turbos running small boost that need good boost control
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Old 07-29-2009, 03:42 PM   #156
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Originally Posted by Cococarbine3 View Post
Dunno if it has already been mentioned, but on Tim's manifold, aren't the exhaust pulses to the turbo going to be slightly off-beat? However, I do not know how much of a difference a few centimeters make.

Compare it to say, an S4 manifold. Is it better to have a short&sweet manifold with offset pulses or a 'roller coaster' path and synchronized pulses? (neglecting EWG for now)
I don't have a good answer, in terms of how much an absolutely perfect length AND bend angle primary manifold helps.

I have limited experience, going the other way, with my BEGI/FM replacement manifold. The middle two primaries are much shorter & straighter compared to the outer two. That manifold on my '94 1.8 made 268rwhp @12psi (GT2560R) with decent spool...not as good spool as Paul/Arties but still great peak hp.
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Old 07-29-2009, 03:49 PM   #157
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you ****'s play nice because you're both working on my car.
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Old 07-29-2009, 03:56 PM   #158
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Originally Posted by Cococarbine3 View Post
Dunno if it has already been mentioned, but on Tim's manifold, aren't the exhaust pulses to the turbo going to be slightly off-beat? However, I do not know how much of a difference a few centimeters make.

Compare it to say, an S4 manifold. Is it better to have a short&sweet manifold with offset pulses or a 'roller coaster' path and synchronized pulses? (neglecting EWG for now)
That's what I've been reading and saying. I guess there is a reason WRC and other turbo race classes run synced-pulse-long-runner manifolds for a reason. Top end I guess. Tim's version may spool better.
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Old 07-29-2009, 04:09 PM   #159
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Originally Posted by TurboTim View Post
1. I have to have a strong opinion!
2. How do you know I never built one?
you said "maybe I should build one"
3. More material? Yes. More cost there, more weight, more heat loss, less stiff.
more weight yes, heat loss is marginal, I'd have to see 100% penetration from your manifold before saying your was stiffer. in any case I haven't heard of a cracked full race mani and they have a few years under their belt
4. More cuts? More STRAIGHT cuts, yes. Straight cuts are easy. collector cuts arent, neither is fitment.
I dont know if you're cuts at #1 and #4 are a perfect 45 but most cuts require some fitting to make perfect. your #2 and #3 took some trail and error im sure
5. Unmatched welds/fully back purged? Debatable. I am not as pretty as a robot welder but I do know my welds are fully penetrated. Definitely a lot more welds to do on those manifolds, but welding is easier/more fun than grinding and fitting. Plus more welds=more chances one of those "fully back purged" welds cracking. Long runner manifolds like that do have harmonic issues on 4cyls. (actually everything does, but the longer the pipe, the worse it is)
yes, the inside of those robot welds looks as pretty as the outside, no sugaring. if you're penetrating 100% without backpurging, your welds are oxidized and no stronger than 75% penetration. the sugaring will affect flow as well. A good weld is as strong as the base metal, so more welds does not = more chances to crack. euqal lenght makes power no arguing that (ramhorns arent usually true equal lenght, but close).
6. Those things cost money? Sure do.
7. They flow better? I disagree. More bends & more length = more restriction. They may make more power in a very narrow window (i.e. cool for drag racers or dyno queens w/anti lag), but spool and overall "area under the curve" won't be close.
they make more power period, but yes especially at peak. they spool slightly slower but in that case a log manifold spools faster, than yours too. more bends and lenght don't equal more restriction, if that was the case, equal lenght manifolds wouldn't outperform. more turbulence=restriction
8. The collector on that mani alone requires a lot more work than my mani? No. You can purchase those collectors already done for not a lot of money. Or if you want to DIY, the straight cut that goes into making a 4-1 collector is significantly easier cause it's made on a straight pipe. ****, you could print out a paper template if you have a halfway decent CAD program, wrap it around the pipe & draw a line with a sharpie, then go to town with your band saw or cutoff wheel. Simple. Quick. Easy. If you screw up following your line, not a big deal. Sand flat with a belt sander. You're making the bends of the primaries mate up to the collector, so the angles don't need to be dead-nuts. Each pipe in my collector has to point exactly where it needs to be, not much room to fudge there.
easier said than done. the first cut is easy, the second is harder to get right. you can sand to perfect but it all takes time and time=money. you can buy a premade collector but it doesnt come ported, or even welded (thats the easy part anyways right). that's what I meant by that comment. I don't think you mess with the inside of your collector at all do you? It'd be hard to get anything way in there


Welding in between the 4 pipes, in the center of the collector, is a real PITA and worth a few hundred to do right there. But I never built one, right?
based off you comment above. and it's not that hard. stick the tungsten way out using a gas lens. figuring the order of welding seems harder to me


Thanks scott. Those pics show a little the effort that goes into it. If you're off a little on the angle of those cuts, you got to start over, so it takes time to do right. You can fudge it and fill in the gaps with welding rod if that's your thing.
All I'm saying is, full race is expensive because that's what the work/quality is worth. I thought they were more than $800 anyway
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Old 07-29-2009, 04:19 PM   #160
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All I'm saying is, full race is expensive because that's what the work/quality is worth. I thought they were more than $800 anyway
I got quoted minimum EUR 1k for a race mani (equal length, firing order, fancy alloy, the works).
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