tughillnut

i am looking into adding twins finally and i dont know much about them. i was wondering what all the twin turbo gurus might recommend givin my sig. i tried reading up whats on here but its hard to find anyone runnin a super b special let alone in a twin scenerio.trying to keep the price reasonable. i just installed the goerend triple disk tc and i have spooling and temp issues which i knew per my discussion with dave but we knew twins would solve these issues.ive been building this truck for years now aand this is the home stretch.any help and ideas welcome.

Tate

For a 64/71, I'd look at an 80+mm compressor on the primary. But for just about every 24v out there, that is way overkill. You'd be better off dropping to a smaller turbo for it, like a Super B/S300g or even a stock turbo, and pair it with 72-75mm primary.

tughillnut

thanks tate for the info.that seems to be what i am hearing from everyone.many years ago when i bought this turbo i thought for sure it was big enough for twins. now i am finding out its right in the middle of what i need. now i am stuck trying to sell the special or trade and then get a kit for the leftover parts needed.thought i was saving money and preparing for the future.any recommendations on kits? i do no towing so not worried about the issues that come with towing. heard bd has some fitment issues and ats are basically same price but better fitment. heard about a place called carls turbos or something like that. he seems well priced compared to others.should i go with built in wastegate or non wastegated for one or both? like i said i dont know much about turbos so i am learning. i do all my own work i dont trust and mechanics in my area as diesel guys are far and few in between.lol at least when it breaks i can only blame myself.

Tate

Build your own. Or go with Crazy Carl's. He builds some neat stuff. You can use the 64 in twins just fine, but it won't improve the response that your converter has reduced. Get a looser converter, or p-pump the truck so you have the fuel to utilize the bigger set of twins.

HOHN

If you have an adequate 'gate on the top turbo, don't go too big. IMO, a 64 on top is too big for anything but a track truck or puller. With those big tires and tighter converter, you need smaller top charger to get things rolling early.

tughillnut

hohn
what size would you recommend? like I said I am a do it yourself person all the way. I see carl sells d tec turbos? I havent herd of them before anyone out there used them before in a twin set up? hows the reliability? I dont know much about turbo talk so ive got alot of research to do on here.do you think I should go with just a smaller turbo to start and see how it runs with the special first and then upgrade? just thinking out loud.

soulezoo

Justins advice is spot on. The super B special you have is really too big for you. Remember that throwing a big turbo underneath for twins will slow the spool down on what you have now. So if you don't like your spool now, just wait, it will be worse.

Judging from your mods, the BD tow twins set up is close to what you want and you have a full kit. (I mention that only because you have a BD turbo)

As a DIY kit the "killer B" is more appropriate and with the big tires/tight converter the "super B" may work better. Then I'd put a s472 (or s475 depends on how much HP you make) under it.

Since I really like Garrett turbos so much I think that the gtx 3582r over the s4xx would be the real deal.

Just more stuff to think about!

tughillnut

well given my sig what appx hp do you think I am at? looked at th twins set up from bd for towing. I know like you said the super b would be better since it has the 57 mm to get it to spool faster. especially since i am considering going larger tires after i wear out the 37's .what size would be better for the larger turbo the 72 or 74? since you recommend both. I have never had the privilege of getting to an open dyno day lol if such a thing exists around here. lol xdp is the only thing close and I never make it there. . I am also going to give bd a call tonight and see what they say also. I like to hear all the input I can to make an educated decision. lol..

soulezoo

I couldn't guess HP for you. Especially with the large tires... you'll have to dyno to know for sure.

Spec'ing turbos without the knowledge of current power or at least a power goal is just throwing darts at a board.

Based on what little info there is, I'd say the super B over a s472 would suffice. The BD tow twins include a 66mm primary turbo IIRC and they are good to about 525 hp and may be all you need. The 472 provides a little more headroom. Too big of turbos for a purpose is as bad as too small a turbo IMO.