Update on group buy of larger exhaust housing for tc78
02-14-2011, 02:52 PM
#101
TECH Enthusiast
Join Date: Jan 2004
Location: New Zealand
Posts: 608
Likes: 0
Received 0 Likes
on
0 Posts
got the last one turbonetics made...
yes its on the Commodore, which is pretty similar to the GTO but 4 door.
I have also stepped my downpipe straight to 3 1/2" off the turbo which made a noticable difference in spool, so I would go 3 1/2 outlet on the housing if you can squeeze the bigger downpipe in.
I have just picked up a damaged Turbonetics T76 Thumper, was going to have the compressor housing/backing plate machined to fit the TC 78,
but now thinking of just having it rebuilt and swapping turbos.....
02-14-2011, 02:56 PM
#102
TECH Enthusiast
Join Date: Jan 2004
Location: New Zealand
Posts: 608
Likes: 0
Received 0 Likes
on
0 Posts
Did anyone ever find out if the turbo inlet flange and vband exit will be in the exact same locations as the original Turbonetics housing? I understand the housing itself may change size but what about the flanges? And do we have a "current price" with the 10 orders so far?
02-14-2011, 03:00 PM
#103
TECH Enthusiast
Join Date: Jan 2004
Location: New Zealand
Posts: 608
Likes: 0
Received 0 Likes
on
0 Posts
Hey Is your .96 undivided. I got a 1.15 but for some reason they sent me a divided housing. I have major back pressure and was wondering if the .96 undivided would get rid of some of that.. not sure what I should go with... or who to listen to anymore....
Lmk if you want to sell it.
Thanks,Chris.
Lmk if you want to sell it.
Thanks,Chris.
your best bet is to jump in on the group buy and step up to 1.32 or 1.52 ar housing.
02-14-2011, 05:01 PM
#105
TECH Enthusiast
Join Date: Jan 2004
Location: New Zealand
Posts: 608
Likes: 0
Received 0 Likes
on
0 Posts
works well for my combo - 383 m6, but hey the 1.52 ar may be better still...
I shift at 6500 rpm (mild turbo cam).
If you have room and don't mind fabbing a 3 1/2" downpipe there are gains to be had. if not stick with what you've got.
If you have an auto and converter you will get away with a bigger AR housing then an M6, lag will be less of an issue.
02-14-2011, 05:38 PM
#106
FWIW I've gone 135mph in the 1/4 on both a .81 and .96 housings with the TC76 with a 4200lb race weight. 3" downpipe 15psi boost on a 370 through a 4L80e. I really hope you guys see some good gains, I just have my doubts that you'll gain much. I sincerely hope I am wrong though.
04-03-2011, 09:46 AM
#112
11 Second Club
iTrader: (11)
Join Date: Dec 2008
Location: San Diego/ from the 316
Posts: 784
Likes: 0
Received 0 Likes
on
0 Posts
i emailed comp while i was still on deployment.. guy said no one ever sent in a turbo for mock up... so i guess the bottom done fell out of this... i am just goin on with the .96
04-04-2011, 07:44 AM
#113
TECH Fanatic
iTrader: (19)
Join Date: Sep 2007
Location: houston TX
Posts: 1,497
Likes: 0
Received 0 Likes
on
0 Posts
well I pm'd Zac about it and he sold his TC without ever sending it in. He didnt tell anybody this so nobody else did either.
I work nights and these next two weeks are going to be a whole new kind of hectic and I wont be able to do much to help but once things die down a little I can speak with Comp an do whats needed to send mine in. Its been sitting here in my closet the whole time so im a little peeved, I could have sent it in anytime I wanted
I work nights and these next two weeks are going to be a whole new kind of hectic and I wont be able to do much to help but once things die down a little I can speak with Comp an do whats needed to send mine in. Its been sitting here in my closet the whole time so im a little peeved, I could have sent it in anytime I wanted
04-04-2011, 09:50 AM
#115
yeah sorry, i sold the tc78 becasue i had just enough room to squeeze a 78gts in to fit
never realized i never posted in here, sorry
there was an honest huge gain going to the GTS, and spool was similar, FWIW
never realized i never posted in here, sorry
there was an honest huge gain going to the GTS, and spool was similar, FWIW
04-04-2011, 08:24 PM
#118
ok
the bearing housing on both the TC and GTS are ~equal in size
as are the exhaust housings on both.... very very similar in size
overall length of the turbos are similar with the GTS being just slightly longer
DP and everything from the TC78 bolted right up to the GTS
The only real size difference is in the compressor cover diameter, I would say the GTS is around ~1.5" larger in diameter
here is the TC78, take note of the distance from the compressor cover to the waterpump snout
and here is the GTS.... I had to grind the compressor cover and the water pump snout the get it to fit, so between those two pics it should give a good idea. You have to realize the compressor is clocked differently so that ate some space up for the GTS too
and watch the vid, it gives a good idea of the differences in size of the compressor housings
http://www.youtube.com/user/rotary13.../2/1L7CY2il5n0
hope that helps guys
04-04-2011, 08:34 PM
#120
and for spool watch this vid, you can see how easily it lights up even with a tight converter
http://www.youtube.com/user/rotary13.../1/q_7bD8ORT_w
and so you know i have ridden in a auto 6.0 with a BW s475 and that thing was LAG CITY
for responsiveness/lag with 1 being fast and slow being 10
tc78= 1
gts78= 3
s475= 10
http://www.youtube.com/user/rotary13.../1/q_7bD8ORT_w
and so you know i have ridden in a auto 6.0 with a BW s475 and that thing was LAG CITY
for responsiveness/lag with 1 being fast and slow being 10
tc78= 1
gts78= 3
s475= 10