donyue

Hi All,

I'm wondering if anyone has installed one of the Gale Banks Twin Turbo SBC kits onto their SBC or Dart SBC in our C3's?

I've been contemplating to do this upgrade to my 427 Dart SHP SBC, but not sure about fitment and other possible issues. From what I can tell the kit comes with an ACCEL DFI system so I would get the benefits of FI and twin turbos at the same time if it will work and fit in the car.

For about $6000 it seems like a viable upgrade to get a twin turbo 427 Dart SHP without spending 35k on a complete crate Nelson Racing Engine.

Besides, I already have the base Dart SHP 427 short block, forged crank, forged pistons, Pro 1 heads, etc. and I think I would be happy with having somewhere between 700 to 800hp without getting the extra 200 to 300hp that a Nelson engine would make.

Anybody have an experience with this?

Thanks

donyue

I have an update to the information about the Banks twin turbo SBC kit. The Banks/Accel DFI portion is extra. But even with the added cost of the Banks/Accel FI kit it would still cost less then an entire 427 twin turbo Nelson Racing engine.

Thoughts?

Gale Banks 80'

I can probably walk You threw most any question You might have as I have had one of these in my 80 since 1987 with the first Gen Carb Version and I now have the 2nd Gen with the Accel injection.
Banks used to make a C3 specific kit but the modern serpentine belt pretty much solves most C3 issues. There is no way the Accel Manifold will fit under a Turbo Hood let alone a stock one. The Turbo Chargers them selves are going to be a Hood issue as well. When I bought my Kit from Banks in 1987 they were re designing there Exhaust Manifolds from the hand welded ones to cast iron and didn't have any available. So I built my own using there blueprint. When I did I positioned the Turbo's right down close the Valve covers and by using a Turbo Hood I have a bit of clearance but not much. When I switched to EFI I also used the Accel, and at the time I had no idea Banks was in the process of doing the same thing at the same time. Anyway I machined about 1 1/4" off the top of the Manifold, at the time the MSD air valve was the shortest and I fit under my Turbo Hood. I have the shorter height Turbo Hood and the taller version would give another inch or so of clearance.
With a 427 SBC I think You are going to have problems getting the Compression down to 10:1 or so that is needed with a Turbo Motor. That's what I'm running on my 400 SBC.

ajrothm

I would love to see some pics of one of these kits installed in a c3. I've always heard about them but never seen one.

Sub'd for the OPs build.

76Rat

10:1 is a little high unless you plan on running race fuel all the time or running very little boost

Gale Banks 80'

In my first Motor I ran 8 to 1 in my 350 CI with a Banks prepped Holly 800 DP HEI and 6al. Iron ported 0441 Heads. On the Dyno the Motor ran great a 3 deg change in timing could make a 140 HP difference. In reality the motor ran like crap on the street it was a real dog off idle just like a low compression motor with to much carb is supposed to be. Fouled Plugs and Turbo lag were the norm.
In my new Motor I increased the CI to 400, am running 180 cc Aluminum AFR Heads and the 10:1 Compression. Coupled with the an ECU running the show the new motor runs great right off idle. It can pull high rear end ratios and OD Trans ratios with out a hitch. Very little Turbo lag. With an ECU you can get away with a higher compression, modern head designs help to. The new 638 HP LS9 Blower Motor comes with 9.1:1, but keep in mind that they need to figure somebody is going to put the cheapest Gas they can in it and try to blow it up on warranty. I find that doing street driving 98% of the time I'm not into Turbo Boost. 90% for Auto Cross.
Most Street Turbo Engines total Boost controlled by the backpressure in the exhaust. Its very hard to make most Boost than Exhaust pressure. I have a full length duel 3" with high flow Cats and the biggest Mufflers that will fit in the stock location. My system is good for about 7 psi Boost. But at 7psi straight a way's get real short real fast.

Gale Banks 80'

Rkreigh

while the SB chevy and Banks setup is nice, it's not intercooled and expensive for 7 psi

I'd like to install a 4.8 LS iron block in my C3 with a custom turbo manifold kit and a pair of T60 turbos.

I have an LPE tuned ECM ready to go and just need to get a 480LE tranny as the current turbo 350 auto won't cut it

this is an ez 1k reliable hp and the rear will soon become the issue

I'm not expecting 100% handling with 1k street hp so I'm looking to go with an autofab rear and gear the car to load the turbos, have decent top end charge, and not so much gear that it won't hook

I'm currently running a TTiX kit in my Z06 running 800 at the tire and it's a really fun car but I'm in love with the 68 looks

Gale Banks 80'

In the modern times of today building a Turbo Motor is easier and will work better than ever. Most V-8 Engines from the late 90's have intake manifolds that look as though they were made for Turbocharging. I once took a Accel Super Ram Manifold and machined a adapter to mount an Air to Water Intercooler in it. I came to the conclusion that I needed to do the whole thing up side down, and run the air in threw the lifter valley and up into Manifold. GM must of thought the same thing, as that's exactly what they did with the LS9. But that leaves that LS9 Manifold as a perfect match for Turbocharging. I understand that the LS9 was originally designed as a Turbo but was changed to the Whipple design when they became more efficient. I still prefer the Turbo's being mounted up top and gravity draining the oil back to the sump. If You have a Turbo engine then its got to look like one. Burying the Turbo's in the A-Arms or replacing the Mufflers with them might be a good compromise but its never going to look right. When my car goes to a show no body asks where are the Turbo's.

69427

Respectfully, I disagree that most street setups rely on backpressure to control the boost. Most setups I've ever seen use a wastegate to control the turbine speed, and therefore the compressor boost.
Any significant backpressure is in the turbine inlet piping (a necessary evil), not in the outlet pipe.

76Rat

Banks also agrees with you. All their systems are sold with different wastegates, depends on the application. Years ago they did not run wastegates but could only build a certain amount of boost depending on the internals of the turbo.

Gale Banks 80'

Oh I have Waste Gates. Using a Pressure gauge we set them up to open at 8 psi. However in the car or on a Dyno they have never once opened.

ajrothm

Thanks for the pic!

That's a pretty wild looking setup, especially considering it was designed in the 80'. Cool stuff.

I'd put some meth on that thing and turn the boost up a few psi.

Gale Banks 80'

The Picture is kind of a lousy one as it was taken shortly after I installed my new Engine and a bunch of stuff up top was thrown together just to make it run. Hence the loop the loop hoses etc. If you look closely at intakes to the Turbo's you can see a water/ methanol injection line. there is a Jet that sprays directly into the Turbo inlet. There is a SS tank buried down in the right fender behind the side vent. A solenoid set for 3 psi opens to allow the tank to be pressurized with boost pressure which feeds the Jets. The more pressure, the more they spray. This was a Banks option back in the 80's.