Thank you, 12vordie.... I have been saying this for years. What a joke what these guys are getting for twins setups...... Whatever......like they say, if someone will pay for it..........

Bottom line, and I have said this many times, if you dont have/know how to weld, you can buy a nice welder, teach yourself how to weld, put together twins and including the cost of the welding machine still be way cheaper that these 'kits'.


HOHN brother, I disagree with you on this one, I feel a 35 is ideal on top, actually, I have looked into an even smaller compressor section (a 30) on a 35/16 housing for street twins. Remember, the top turbo is being fed with air at 15 to 20 Psi above atmospheric. Look at your density curves and compare volume flow and mass flow at atmospheric vs 20Psi above atm....... got to allways run the numbers using mass, then convert the massflow back into volume flow using the calculated density, to check for velocity/choking. You will find that a 35 compressor section as the second stage compressor, can easily deliver mass flow numbers required to support 600+HP when being fed with 25 Psi (qauge) air from the primary compressor....



KP

 

they are not that hard to build, but it does take some time. don't get your hopes up that you will finish it in a few evening work. we put 80 hours into a set on a 3rd gen, but we built a exhaust manifold also. and this is in a shop with way better tools than most have accese to. and with 2 of us that have over 20 years welding and fabbing tube.

 

Well, with a complete machine shop at my disposale, all the fab equipment you could dream of and plenty of years fabing from blueprints, I feel more than confident that I can handle it MAYBE? But I would rather spend two months putting it together and be able to tell people that I did the work, not some overpriced perfomance shop, and still hang with the fat wallets that blew 4 grand foolishly. I just want to build something that will be friendly on the street, but will light'em up on demand, something good for atleast 500hp. I am not looking for a truck that is only good for 1/4 mile runs. And I want twins

 

i certainly would NOT think twice about charging somebody 4 grand for sending somebody a new manifold, TWO new turbos, a very expensive wastegate, AND everything to put them together with. powdercoated. until you build a set, in your own shop, that YOU and only you pay for and bought all the equipment for, not in the shop "you have access to", i'd say you're standing on slightly shaky ground.

whew. got it out.

disclaimer: i am NOT trying to start an argument here. i felt the same way until i built mine. and i DID know what i was getting into.

dave

on edit: i'm not saying that i don't think the average joe wouldn't be able to do it. it was a lot easier than i was expecting, the components were just a lot more than i was expecting. and as an afterthought, the average joe doesn't know what a 220 plug looks like. kinda like i don't know anything about plumbing. and i AM NOT about to change a toilet. i'm VERY happy to pay somebody just about whatever they want to do that.

sorry to rant off topic here. i won't do it again. btw 12vordie, i think that you'll be able to do it with your eyes closed.
dave

 

On a lighter note...I know a guy that moved to Iola.

 

Look at it this way, those over priced performance companies that want to charge $3500.00 and up for a twin setup can still not have more than two grand invested in parts, so what, they want to charge $2000.00 in labor for production of these parts, what a joke. Please correct me if I am wrong. It appears that the only thing they are trying to do is keep the setups out of the hands of the average Joe, trying to make them look like they are an exclusive toy for the fat wallets . I would love to own a set custom built twins from a reputable performance company, but I don't think I could really ever spend that kind of money for so little, besides, my wife would kill me. HEY, when you spend that kind of money on a turbo setup, do they send you a big ole tube of KY?

 

I too think a 35 is ideal in many ways-- the BIGGEST being that it's FREE! I can't see myself building a set of twins and NOT using the stock turbo. I'd find a way to make it work just to keep cost down.

My comments on the 35's compressor being too small are just regurgitation of things I've read that made sense to me. True, when compounded, the 35's compressor can go a LOT farther. But the 35's compressor has to spin faster and compress less efficiently, imo.

The main problem with the Holset chargers mostly available to us is that they are ALL designed for relatively low pressure ratios. A 35, a 40, an HT3B-- they are ALL designed for max efficiency around 20psi. But they obviously flow VERY different quantities of air.

Because we are heavily boosting a small engine (as opposed to lightly boosting a LARGE 18-wheeler engine), we need a VERY high PR turbo-- something that's efficient to 40-45psi. Not just acceptable, but actually making EFFICIENT boost.

Now you hit another problem. You design a compressor that's in the MEAT of it's map at 40psi, and the compressor map is so narrow it's all but useless-- it's flame-shaped. So it surges like crazy, and it's so temperamental that no one could tolerate it.

This is why twins are SO good. You can have BOTH turbos spinning along in the meat of their maps at 20-22psi and support lots of HP.

Personally, I think the new Super 40 from Holset is going to be my first choice for an upgraded single that can be used in twins later. The compressor on this thing is MUCH better than an off-the-shelf 40, and much closer to what we need on our 5.9s.

Yes, it will be sorta fragile, and I'm not gonna be able to hit it hard, but once it's in a twins setup, it should live just fine.

Your take, Kev?

jlh

 

I think an hybrid 35/40 is great in a twin setup but I would really like to have my 35 teamed with a super 40 compressor that would move plenty of air and has a wider map than a standard 40, I would think a super 40/35 hybrid would compete with the smaller S-300s and be much more economical

 

sorry about the seemingly hot-headed post earlier folks. just had a tussle with the ol' lady and wasn't thinking clearly. i hope i didn't offend anyone. got LOTS of respect for everybody on here.

dave

 

How about an HX-50 for the top and a HT3B on the bottom this work at all I already have the 50. I figure it would work good for sick top end but bottom end and around town driving would be crap.

 

"quoted form a post by GO 4LO
Turbo______CFM______Racing HP____Daily HP
HX35______600________420_________330
HX40______800________560_________440
T66_______800________560 _________440
B1________900________630_________495
H2E_______1000_______700_________550
HX50______1000_______700_________550
HX55______1050_______735_________578
HT3B______1100_______770_________605
T76_______1350_______945 _________743
HT60______1400_______980_________770
B2________1500_______1050________825
HX60______1550_______1085________853
T88_____1450-1750__1015-1225____798-963
HT4B______1800_______1260________990
Big Brother_1900_______1330________1045
T91_______2000_______1400________1100
HC5A/HX82_2450_______1715________1348
T100______2600_______1820________1430
T105______2900_______2030________1595"

The super HX40 is 850 and the Pro 52 is 1200"

Copied from the TDR web site..

If you look at the flow numbers for the 50's and 55's.. they are not that far from the HT3B... If you already had a 50 or 55.. it would be cheap/easy to use, but no idea what you would need for a housing.. When you step up to a 60 or B2 it a jump in size.. (The Big Brother's out there..) Some of this depends on how heavy you plan to fuel.. I think the little turbos will make a killer towing/steet setup.. but for racing/pulling they might be a little limited on top.. and would need a ex-gate..

Using a 50 for the little turbo.. will give lots of lag... even a built turbo.. (but like CIO said.. it would flow good once you got it going..) if you went with the 50 on top.. I think you need something.. MUCH bigger than a HT3B...

Just remember, we are after flow, not pressure with the twins.. (yes easy to build pressure.) but we want to have good flow, and less drive pressure.. Once the big charge is up and going its going to do the work...

NMP.. you going to setup those first gens a twin package... It looks very tight... but its looking good..

12vordie, are going to make it to the truck/tractor pull on July 2-3?? Just north of Hillsburo. (Carls Corner).. Gunracer's thinking about it.. there will be a few of us there.. not sure how many will be pulling...

Ok.. I'm done rammmbling..
Bryan

 

A 50 as the top turbo of a twinned 5.9 liter engine would be an abomination for anything other than 6,000 RPM+ sledpulling duty. You guys need to remember what twins really are.... they are compounded compressors and tandem turbines. The secondary compressor can be much much smaller than an equivalently sized single for the same power output, due to the increased density. Its all about MASS FLOW not volume flow....




KP

 

Has anyone put the new super 40 cold side on a 35 to make the super 35-40 turbo yet!

 

50 on top... I'm sure there are others.. but BBD was running a Pro 52 on top, with a Big Brother on bottom.. but not sure he is still running this combo.. but its a puller only.. not 6Gs.. but up there..
What I ment to say was to try the 50 or 55 on the bottom.. it might run out on top (high RPMS).. but if you already have one for free... go for it...

KP... describe Mass Flow... and volume flow... I'm a little confused...
Thanks
Bryan

 

If I can get an HT3B for less than $568.00 and I can get my stock turbo modified by HTT for cheap, then why does everyone want the ridiculous amount of money for a twin setup?

there is a 3b on ebay right now for about 200