If we are talking heavy street cars (4200+lbs) how would this compare to a single 61BB or 67BB for spool and low end power? Cost wise, yes rough estimate is perfectly fine, how would this as a package (headers and fresh stockers) compare to a set of Poston's and a 6776BB?
Where are the twins?
- Thread starter tracer
- Start date
- Joined
- May 27, 2001
Im hoping the whole system comes in around $2500ish. That would be headers, downpipe, wastegates and oiling setup. Stockers can be had for next to nothing so figure $800 for a pair maybe.. I really dont know.
Things you'll need to make it work:
Some kind of engine management system or MAFT
A front mount
Several bags of oil dry to clean up the mess you'll make when you turn the boost too high
Things you'll need to make it work:
Some kind of engine management system or MAFT
A front mount
Several bags of oil dry to clean up the mess you'll make when you turn the boost too high
turboanthoni
Member
- Joined
- Mar 13, 2005
Twin kit
I have drove the car with the original twin kit that this was designed from. That car had 60s with .63 t4/t3 hybrid exhaust housing . This car was a stage 1 with 8445 iron heads .(248ci) It had a 3200 converter (and did'nt need that much stall)We felt like a 2800 would've been the perfect fit. I know these are better design as for fit and performance as the primaries are more equal in length and the downpipes are easier to installs .Other people can agree with me that seen the original kit a few years ago (Patrick Rubio, Dave Fiscus, Ken Haygood,Greg Crow ,Kip Asplund,) and maybe a few others I can't remember . I've had hands on these headers before anyone else .
Now Jay since you where all torn and bothered don't you think Burhead deserves and apology!!!!!!!!!!!!! And please don't belittle yourself and delete this ! Just my 2 cents from a Ole Hillbilly that just don't care anymore !
I have drove the car with the original twin kit that this was designed from. That car had 60s with .63 t4/t3 hybrid exhaust housing . This car was a stage 1 with 8445 iron heads .(248ci) It had a 3200 converter (and did'nt need that much stall)We felt like a 2800 would've been the perfect fit. I know these are better design as for fit and performance as the primaries are more equal in length and the downpipes are easier to installs .Other people can agree with me that seen the original kit a few years ago (Patrick Rubio, Dave Fiscus, Ken Haygood,Greg Crow ,Kip Asplund,) and maybe a few others I can't remember . I've had hands on these headers before anyone else .
Now Jay since you where all torn and bothered don't you think Burhead deserves and apology!!!!!!!!!!!!! And please don't belittle yourself and delete this ! Just my 2 cents from a Ole Hillbilly that just don't care anymore !
Well I wouldn't need the downpipes or oiling since I'm non G-body and I have deltagates already so thats pretty much down to the headers and then the turbos. Would you sell just the headers and what kind of material are you making them out of?
With a 4200lb+ Riviera I need lots of low end stuff but I can't go blowing the crank out of the block with an ungirdled 4.1L block since the girdle won't clear the chassis. How do you think the spool would be on these matched with a 3000rpm LUC on a 212/212 stock stroke 4.1L motor? Twins would be so much visually cleaner on my Riviera with its X frame since I don't have a lot of downpipe clearance between the frame and the toe boards. 2.5" pipe is a tight fit, but 2x2.5" downpipes is plenty and helps me keep twin tailpipes.
Thanks,
This is but one beauty of this project, the spooling capiblities... The smaller two turbos will spool much faster with alot lower stall... Two stockers should basically be spooling with the slighest bit of throttle, espically on a car with the right cam and some head work....
One concern, bracing... Have you considered putting some bracing for the turbo mounts off of say the power steering mount or intercooler bracket on the drivers side and stock type bracing on the passengers side? With a turbo cantilevered that far out there with all the heat that will be in it, I'd be concerned with cracking without some sort of bracing. Also what material are you using on these? Mild Steel, 321 Stainless? I vote for mild steel and ceramic coating to keep cost down and my metalogist friend says that 304 is prone to produce carbides when welded that compromise the integrity of the weld due to gavlinic corrossion between the steel and the carbides. 321 would just be rediculously expensive.
- Joined
- May 27, 2001
Peter,
Twins will spool with less effort.
Look at how Chris can spool Twin GT42Rs compared to a 101 Thumper.
To a certian extent you get more efficiency out of 3 cylinders since you loose the heat and pressure loss in the cross over. Also you have lower component enertia since the wheels are smaller in diameter and lighter over all. Small turbos are also cheaper and easier to package both with the physical size and the downpipe requirements.
The down side would be that you only have 1/2 the cylinder volume per turbo to get things going and with the lower component enertia you also have greater chances of compressor stall and blow back if you snap the blades shut and the air stacks up in the tubes. You also have a bit more mechanical losses with double the number of bearings
thats a good comparison if a 101mm turbo has roughly 8012mm² of inlet area, 2 GT42R turbos (94mm) have 13880mm² of inlet area. That's a 73% larger inlet area being spooled much faster than its smaller (area wise) single counterpart.
John,
I've never seen Chris' car with a 101 Thumper. I'd love to see the comparison.
That makes sense. Although I know that the Supra 2JZ is an amazing motor and we can't compare a Buick V6 to the 2JZ, it amazes me the turbos and power those guys make. The vast majority of them do it with 1 large turbo instead of smaller twins. It's rare to see a TT Supra make over 1000rwhp yet the big single guys can hit the number quite easily.
Straight Sixes are a different game than a V, the stock TT setup on a Supra is a sequential which is good for a quick spool to get it going and then the larger turbo gets the airflow for the big numbers. I also think its a space issue with trying to fit 2 bigger turbos in engine bay since everything has to be mounted below hood level and on one side of the block which would potentially interfere with the suspension mounting. Don't know for sure on that one since I've never studied the underhood area of a Supra or a Lexus SC300.
Not trying to be sarcastic here, but what are you trying to get at?
EDIT: I thought you were the same person that had posted about Burhead earlier... guess not.
- Joined
- May 27, 2001
Fixed your link for you.
- Joined
- May 27, 2001
The GT42 have a 74MM Inducer, the Exducer is 94MM.
That 101 Has a 101MM Inducer and Exducer is closer to 130MM.
Still a larger 8601mm² inlet area, but thats down to a 7% larger area. Was the thumper a BB or journal bearing?
- Joined
- May 27, 2001
Sorry for the confusion, there was no direct comparison on the same motor.
I was making that call based on the friends I have with single turbo cars.
Chris's car you could race off of the foot break...
Most of the single turbo guys use a 2 or 3 step.
I would like to see how much faster the BB Thumpers spool but I still don't
think they will compare. Garrett's Largest BB Thumper Unit is was the GT55 rated at ~1500HP while our Twin GT42Rs are rated at about 2000 for the set.
Turbonetics has their single BB Thumpers but I do not have a lot of data to compare.
