I know that having longer exhaust headers can net more horsepower, since the pulses line up and have more space to sort them selves out and prevent gasses from another exhaust port from pushing into it's neighbor, but I haven't been able to find any good arguments about having the turbo on top or on bottom.
Touche. My thinking is along the lines of your next sentence- longevity as well. Sure turbos are meant to see heat but within reason. Too much heat is just too much heat and can lead to failure especially with smaller turbos that are fire crotches to begin with. My thoughts and I'm sure that I could probably a paragraph or two somewhere about this are that you need that heat as well as volume to give an adequate spool....but ultimately still want to get that heat out of the exhaust side (the scroll itself) as much as possible. Sure they're designed to be beat on but too much is too much and that goes for anything. You could apply that to bowls of cereal if you wanted to.
I know you've looked at the stock ex man when it's been beat on and you lift up the hood on a dark night. You could light a neighborhood with the orange glow alone. Now look at some badass turbo setups on youtube : IE engine out of the car and on a dyno test stand. The piping glows under load (boost) but off boost quickly cools down again. This is an example of some badass designing by people who actually care to be that anal and do the job right. Thats my only point really. I live in California and it's pretty hard if not completely impossible to drive around with something badass and not want to beat on it. The problem is the fines if you're caught. I know why I havent done anything really radical with my MX6 and thats a big part of it right there. But for some of you other guys...why not?
Quote:
Originally Posted by Ragnarock01
I can see what you mean about the heat though now that I think about it more. At least if the pipes curve down first, that rising, radiated heat stays around the turbo rather than floating above it with a bottom-mount.
Yeah it just sits there more or less. With a large turbo fine..you want some heat to keep velocity up. But with a small turbo or even some of the T3's here..the stocker is really all you need. Big turbos like the Holsets need help whenever they can get it. I dont know, we'll see I guess.
Quote:
Originally Posted by Ragnarock01
I would love to see some definitive numbers on this; a comparison between a top and bottom mount manifold with equal-length runners would be the best, but I can't find any tests like that (so far).
I have tons of books and I'm sure that if I dug deep I could find something somewhere. I want to find a reliable source though. I'm off this entire weekend so....I'll have something definative either way.
The compressor housing is huge but the turbine wheel and compressor wheel are more than usable according to map plots.
Compared to the stock VJ11 lol
jesus christ. so spool times would stay within a usable range for the F2T's relatively low redline, but 8psi on that thing looks like it'd be 20psi on the vj11
im not confused at all. you can play dumb but i know exactly what you were implying from your first post, which is the same bs you've been posting for a while. plenty of people run great ets with fwd....so quit hating and give it a rest already
Last edited by zlyricist : 1-16-09 at 16:09.
Reason: but anyways, back on topic....
you can derive whatever you want from my post. i wasn't implying anything. i was purely posting about my personal decision. you take every one of my posts personally and i'm still not sure why you're the only one to get worked up over them.
but w/e,
the only issue i see with this setup is the same things people have been posting about. melting wires etc. but in reality, if you're going to melt the wires with the turbo mounted that way, your wires should be melting already from the factory exhaust manifold.
invest in some wire shields and be done.
the reason why no one does this is because no one wants to pay to have a manifold made, and as sick said, most are blocked inside a 6 sided cube.
I drove my MX6 today for the first time in probably a year. All it took to get it started was alittle gas and the battery to be charged. I've been driving my Integra for most of the year and the past few months a borrowed Camry. I forgot what it was like to have usable torque and scared the crap out of a friend who's never seen it drive....nor been in the car.
It's parked in the garage for now until I get it registered and smogged again but once thats done I'll have 2 years to do whatever I want with the exhaust and turbo. Talk about motivation, that torque was all I needed.
I think I'll give it a go and I'm rethinking what I'm going to sell- right away at least.
No seriously it's good to hear that some motivation has hit you.
It's cool when at any idle moment ideas of what you want to do to your car keep running though your head.
Some pie in the sky stuff but some so brilliantly simple (in theory anyway)
Well even if you AREN'T considering a top mount this is an excellant turbo to buy. The only issue you'd have is the exhaust flange because if you notice the stock elbow for that GM3 would point your exhaust to the hood- or you could cut a hole in your hood!
Specs on the GM1-8 vary but this is a GM3 which is a very nice turbo overall- even in the GM circles- they like the 3 over the others. It's an RHC6 which has enough flow for 400+hp (low 400+) and has peak flow in the 600-700CFM range. The good part is that the flow maps for the RCH6 still show a surge line low on the left which means it still has good flow low rpm- low or high boost so you dont get much surge with it and at the same time is in the TO4B range in size. Also, the turbine inlet is a standard T3- the exhaust on the 3's is an internal wastegate with a flapper just like our stock RHB5.
The GM8 for example has an exhaust housing similar to the T3 where the side wall is flat and the flapper is incorporated into the exhaust elbow rather than the exhaust scroll on the exhaust housing. I would expect to see that turbo go for $200-$300 but it's worth a hell of a lot more new (in the condition it is it seems) and diesel shops sell these same turbos without heat shield and exhaust elbow, some even without wastegates so you buy their diesel gates instead and pay moar Robert DeNetZero. They commonly sell the entire unit for over $1,200-$1,600, remanufactured usually go for around $900 with $200 core charge.
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