Ok, here's the deal... This winter I will be upgrading my stock twin turbos to something a bit more powerful, a bit less complex, and hopefully a lot more aesthetically pleasing....

Options:
-Large single turbo such as a PT-88 or a Garret GT42
-Dual 60-1s
-Upgraded stock twins
-Tripple T3 turbos

Now, money is not a HUGE factor here, all of these are feasible with the budget I have for the winter. I will be putting a clutch assisted Geforce tranny in, along with a Kaaz LSD (we'll see if that will hold). I'll also be putting in either a carbon fiber or chromoly driveshaft and some chromoly axels. I really DO NOT want to go to a 4-link setup... but I will if this setup fails.

My goal is 700 rwhp. I want the ability (with proper driving and safety of course) to dip my street trimmed car into the 9s.

Large Turbo option:
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I already have someon making me a manifold for this, but they haven't started yet. The manifold is paid for, but I'm not in a huge hurry for it. I will need a large wastegate, hopefully the new Tial 60mm dealie, but maybe the HKS GT 60mm. I think that a large single on a 20B would not suffer from too much lag because of the shear torque the motor puts out... but, this is a street car with the dragstrip as its second home. The PT-88 is basically a large T-frame turbo (like the T-76) machined and with an 88mm Thumper-88 compressor inside. Everyone knows about the knew dual ball bearing Garret turbos, which is what the GT42 is. Both turbos are similarly priced, so that isn't an option. Right now, I'm thinking the PT-88 would make a fantastic drag turbo, but may not have the responsiveness of the dual ball bearing GT42. Any input?

Dual T04 Option:
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I've never seen it done. I would like to put a couple of 60-1 turbos on my car. Since the manifold maker has not started, I could pay him some extra dough and have him make a twin turbo manifold for me. Would a setup like this require 2 wastegates? or would I be fine with one larger wastegate? Also, custom twin turbos is something I'm quite blue on... would I want to go with the same specs on each turbo, such as a .96 undivided housing for both... or possibly a .81 and a .96 to sort of help with spool up. I'm leaning towards this option because it is pretty original as far as I'm concerned, and I want my car to stand out. Complexity is not an issue, nor is price... it's a bit more expensive than the single turbo option, but I think it may perform better on the street and still give me the timeslips I'm looking for.

Upgraded Twins:
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Pettit offers an upgrade and rebuild of your 20B stock turbos to utilize S5 T2 compressor wheels. This runs $1800. I doubt my car would run mid 10s with these turbos, but spool would be fantastic... and come on, who really needs to hit 9s? This is my last resort option, and i don't think that I'll be going with this at all... I just had to through it out there.

Tripple T3s:
---------------
This won't happen, but I had to throw it out. One T3 per rotor... in theory, sounds badass... lag would theoretically be non existent. HP may not be as high as I'd hoped, and the timeslips wouldn't be there. The plumbing could potentially be a nightmare, and I'm not sure if I could talk my manifold builder into doing this or not... it'd probably be cost prohibitive...

Well, the way I see it, these are my options. The dual T04 setup is a VERY big possibility and I think it would be as feasible as a single turbo system. I'm open to ANY opinions here... especially on suggestions for the exhaust side of the 60-1s... or even if I should used the 60-1s... maybe I should get dual chrome ***** GT3540s NOT! However, if you think another dual turbo option would be better, like maybe 60-1 hifi, or a 62-1, or even a couple of T04S turbos... let me know. The 60-1 is really the only T04 that I've had experience with (had one on my 13bt and made 430 bhp with it on a crappy tuned E6K map).

 

Again, I am in the same boat. I am looking at the the T76 size compressors...

Also, how in the hell do you plan on putting that much power to the ground?

 

I say go for the dual BB single

 

hey nick did greg show you pics of the k2rd twin turbo manifold? for your twin turbo option if you went internal wastegate you eliminate most of the plumbing hassle. it looks cool too

mike

 

No, I haven't seen that manifold yet... that sounds VERY intriguing... So Mike, what do you think? Big turbo or dual T04s?

 

i would be tempted to go with 2 smaller singles,
like these




look how simple the manifold is

mike

 

but thats for a two rotor. You could do that on a 3 rotor w/ 3 cheap (factory, possibly three HT-18'sor 3 mitsu snails) singles.

 

I wonder what those are? They obviously have internal wastegates which would cut down a LOT on the fabricaton... something to definitely think about.

Something else to think about.. Zach and I were pondering of engines and such over beers a few weeks ago and he pointed out that just about everyone out there (besides race cars and RX7s) use internal wastegates. Do we just like to make things complex? or do we really benefit from them... Maybe its the fact that the rotary can push such massive amounts of air that a separate wastegate just makes sense.

About that manifold, yes, its simple... but thats a 2 rotor flange... try thinking up a way to do 2 turbos off of 3 rotors. Only thing we can think of is to collect all 3 rotors and then split them off to two flanges... which is not optimal because you loose exhaust direction and other lovely features. I thought about using 2 divided housing turbos... then using the front rotor for one turbo, the rear rotor for the other and splitting the center between the two, but then you would be putting extra stress on the center rotor....

this blows. I'm tired, but at least my radiator is fixed

 

I think its a lot of the import aftermarket world that uses them.
You're paying for it, show it off.

 

those turbo's are gt3835's i think. and yes splitting 3 in to 2 is the hard part, i cant get my head around that one either. if you look at the facotry twins they have one turbo for the rear rotor and one turbo for the front 2 (basically) maybe that would work? i might go single just because its simpler.
the external wastegate: i like them but internal is a lot cheaper and less hassle

mike

 

Does anyone know why they always cut a notch out of each bolt hole on the main engine flange? Is this needed? Also do you know what that manifold is made out of j9fd3s?

 

i think the notches are for expansion, but it could also be something dumb like it easier to make.
that is a prototype www.k2rd.com manifold, i think that one is mild steel, but it would not be hard to do ss

mike

 

I was also thinking it was for ease of making, maybe they cut them out with a guided plasma cutter and this was it doesn't have to be "re set" to cut the 4 stud holes. When I had Gregs 13b manifold here that was made by SPF I took every measurement off it. It just had holes that were cut to .510 which I'm assuming is enough for expansion because the studs are .3xx.
Sure looks like 304 to me, has that same gray tint to it my 304 does.

 

I know that Kevin Wyum (out of Minneapolis) from ASP has twin T-66's Turbonetics BB's on his 3rd gen. On our 20B, you should be able to easily do the same with a larger turbine. Or maybe T-72's.

I'll just stick with my T-76. When my car is up and running I'll let you know what it's like since this turbo is such a pig...it's huge! 1.32 turbine, 0.72 AR compressor... Q-trim Since you and I are building our motors almost identically...we have the same thought in mind. It'd be interesting to see how (if we do different turbos) much of a difference is made by the different computer, boost controller, turbo...

 

u could have the front rotor and rear rotor x each other.then have the middle rotor run up the middle of the x.kind of like a x with a middle leg.

 

Why not just split the exhaust fromthe center rotor sending half to each turbo?

I know there is something I am missing in this equasion.

BUt I was tossing the idea of two T04's as well but came up with the plumbing problems as well.

 

he just explained why u cant do this. splitting it in half would put unequal pressure on the middle rotor.

 

Ha! hA! I know run one turbo on the front rotor and one on the rear and run the center just going to the exhaust

I know what you're thinking I know I am a gene-***.
(J/K)

 

You'll have one loud pulse with two quite ones. It'll sound unique.

 

ok heres a crazy idea. in the rotary performance section they were talking about different exhaust sleeves. why not divide the port in two, the upper half and the lower half. that gives you 6 pipes, 6/3=2

mike

 

Nick Talk to Marcos at MVA regarding a twin turbo for the 3 rotor. Im not sure of his number but if you do a search on MVA you should find it. Im too lazy to look

 

nick , i also think that the 3 t3 turbos would make great power and would be trick.

 

Put Three Grand National Turbos on there

 

alex wants to build a 3 turbo manifold, like the one up in the pics up there. the fd runs now and it builds boost right now!

mike

 

Hmm I'm going to say, keep it simple and just do a single.

B