[chevy406]

had to drill down to page 3 to find my build since I haven't done any work on it for a while

So I met my goal of driving the car around naturally aspirated this summer. After taking a last drive out to the CBI December show, I recently pulled the radiator to figure out what style of intercooler to buy. A friend convinced me to go with a simple air-to-air, so I built a template of a Treadstone air-to-air intercooler with two 2½" inlets and one 3" outlet. What do you all think about having a center outlet to the throttle body hat vs two side outlets curved around the radiator and merging in front of the hat? If I go with the center outlet it will require dropping the radiator an inch or two and modifying the top of the radiator support, but both of those changes are easy enough. This gives a pretty clean look with minimal flow direction changes.

I have also started modifying the truck manifolds with 2½" v-bands and cleaning off extra tabs & casting numbers. I'll have to work up some pictures of the manifolds later.

 

[chevy406]

Well, Treadstone failed to get me the intercooler while I was off work for a week , but I finally got it last night. It looks like with a little clearance work on the radiator support I will be able to install the TRTTC9 intercooler 2" forward (toward the grill) of the radiator support. With 2½" silicon 90° bends on the intercooler inlets and a 3" silicon 90° on the outlet it should even clear my old Griffin radiator.

Over Christmas holiday I finalized the location of the turbos and started the hot-side plumbing. After spending several hours on each truck manifold to smooth off the castings and cut off the flanges, I abandoned them. They were placing the turbos too far forward. I found in my case the C6 manifolds turned forward and down made a very easy 180° turn right into the T4 flange using a mandrel bent 180°. The driver's side will be tricky to work around my steering shaft - I'll have to add another u-joint. And the down pipe on the driver's side will be pretty tight. Other than that, everything lays out very nice and simple. Here is a conceptual picture of placement. The passenger side turbo inlet is the only pipe connected at this point. I need to make turbo supports and get rid of the PVC support... Feels really good to finally make some forward progress.

A slight miter cut helps roll the 180° mandrel bend up to the T4 flange:

 

[Potey]

Awesome build, thanks for going into such detail on everything and keeping up with the pictures. Looking forward to seeing it complete with the turbos and what kinda times it going to put down.

 

[chevy406]

Pretty content with my progress this weekend. Basically I just got the intercooler installed, but it took quite a bit of fabrication to get there. I had to cut the bottom off the radiator support, notch the corners of the radiator support for the IC inlets, and trim the inner fenders. Then I had to fab a filler panel to close the radiator support around the IC and a couple little close-out plates for where I cut the radiator support. I also received some more mandrel bends from Columbia River this week. Two 18° 3" aluminum bends will connect the IC to the TB hat and two 90° 2½" bends will connect each turbo to the IC. And the cool thing is - the hood still closes. Lastly I rigged up a couple supports for the turbos to get rid of the "helping hands". Now it's time to finish up the hot piping to the passenger turbo, and then move on the the more difficult driver's side. I did take a step or two back though - my old Griffin radiator is 1½" too wide and my 6" clearance between the IC and water pump will need new electric cooling fan(s). McCarthy warned me that the silicon elbows will blow off once I start turning up the boost, but I'll keep them for now. Later I can weld up some better aluminum elbows. On to some pictures:

The compressed air lines from turbos to IC look like they will be simple with maybe just one weld to extend the horizontal leg.

 

[chevy406]

It's time for a 5-month update - I had to go all the way back to page 7 to find this build thread . Ever since January I haven't had much time to work on the Nova due to other projects... but now with the backlog cleared up I have been able to work a little here and there on it the past couple of weeks. Both 2½" hot pipes from the manifolds into the T4 flanges are complete. I used three 2½" U-bends, two T4 flanges and two C6 flanges to route the tubing under the engine mounts. It takes a fair amount of heat and hammer to form a round peg into an oval T4 flange.

Today I added some 1-7/8" tubing for the Tial 44mm wastegates - just tacked on for now. Here is what the hot side looks like at this point:

It gets pretty busy with the radiator/fan assembly, alternator, etc.. I'll need to either re-clock the alternator or use a different one to keep the wiring away from the hot pipes.

And here is an overall shot with the new radiator/fan assembly mocked in place. Note that at the recommendation from some friends I ditched the 3" silicon elbow coming out of the intercooler and had a cast aluminum elbow welded in place. So far the aluminum welding is the only thing I had to farm out. I started polishing the top intercooler tank and elbow, but still have a ways to go there.

You can see my ¼" stainless steel oil supply tubing is complete. I also have two -10AN fittings welded to the oil pan for the turbo drains - one on each side of the #1 main cap.

Even with this recent spurt of progress there is still so much remaining. But the good thing is I have purchased almost everything needed to get it running with boost. I just need to spend time on it. Biggest things left are fabricating the downpipes, modifying the steering linkage, and mounting the radiator and finishing up a bunch of little loose ends.

 

[tattooedsgt]

I just read your entire post. Awsome job man!!! I recently just bought a LS1 out of 1999 camaro and im trying to figure out a direction i wanna go with the motor. Im on a super tight budget. I could only dream of having a twin turbo LS motor in the ol nova.

 

[Dub]

I took a ride in a ls1 turbo wagon the other day and I can tell you that you are going to needs some big ***** tires to keep your nova going straight. great job.... Work looks top shelf

 

[chevy406]

Im on a super tight budget. I could only dream of having a twin turbo LS motor in the ol nova.

Trust me, my progress and budget has basically been spread out over the past 25 years starting in 1987 with a rusty '68 Nova in college. That gave way to the current '69 Nova in 1997. While there is no way of getting around spending quite a bit of money to build a strong LSx engine and adding boost, if you spread it over enough years it can be affordable. I also work on other people's cars in order to build up my car project funds. I try to keep my hobby spending separate from the family budget.

Dub - I hear you about traction concerns. I'll be trying to apply as much power to 275-60-15 drag radials as they can hold. Once I get the thing running it will be time to focus on boost control. But I'm sure there will be a mini-tub story in the future. Reference the above paragraph about time and money

In other news - I started tearing into the valvetrain on my Corvette AGAIN last night. It has developed a valvetrain noise again, so I am going to investigate the condition of the timing set, cam, and lifters before it gets worse.

 

[Rockytop Wagon]

I love this build any updates?

 

[chevy406]

Last year I kind of promised myself that I would drive the Nova with turbos to this annual car show at my daughter's school. For the past 2 weeks I hit it pretty hard, and had to really I thrash on it the past 2 nights. But at 10 this morning I actually did fire it up. Without more than pulling it out into the driveway, I loaded up my daughter and drove it - open downpipes and all, the 5 miles to the car show. It wasn't a spectacular maiden voyage but I drove there and back without assistance. Currently it's running open loop and I still had the stock MAP sensor so I didn't push it any. It was running hot, which I think is because the fans are reversed. Still a ton of things to get it where I can lean on some power, but I am re-invigorated by hearing it run. Even with open exhaust you can hear the turbos. I can only guess what they will sound like at WOT.
Proof that it left the basement:

 

[chevy406]

In the past 4 weeks I finished routing my 3" downpipes to connect to the old 3" exhaust and Flowmasters. Finally finished that earlier this week along with routing ¼" stainless steel hard tubing to the wastegates and blowoff valve. Also added a 3-bar MAP sensor and made a stab at a starting tune for boost. Last night I cut up a couple 4" aluminum 90° bends to install cone air filters behind the headlights. Inlet Air Temp sensor is threaded into my carb hat; wideband O2 sensor installed in the exhaust... it's about time to put it back on the ground and datalog for some tuning. Maybe I'll have some video to add in a week or two. Biggest thing left for this weekend is to modify the driver's side inner fender for clearance around the turbo. I also have a lot of polishing on the aluminum pipe and intercooler.

 

[69bigblock]

That thing just looks nasty.....

 

[chevy406]

Spent a weekend without lifting a wrench for once. I took the Nova to a local car meet and got to catch up with a lot of friends. Then I spent the rest of Saturday afternoon driving, logging data, changing fuel & spark tables, and enjoying the drive. Ran 1½ tanks of gas through it without a hick-up. There are some things to change though. My well used PTC 10" converter is flashing to 5,900 rpm. That doesn't give the street tires much of a chance in any gear. I'll probably go ahead and make a few track passes as-is, but the converter will be coming out pretty soon to get tightened up. Fortunately I work close enough to PTC that I can drop it off at their shop. Also my thermostat must be 195°. I didn't have any over-temp problems in this nice cool air, but I would like to drop the operating temp down to 180°. Overall though it was a successful street debut.

Here's a couple fresh pictures out in the sunlight:

A little old-meets-new: Laptop computer & HP Tuners riding shotgun in a 1969 Nova.

 

[fencepost]

Great looking car glad to hear you got it back on the road. Gotta nice stance too, I really like that.

 

[chevy406]

Loaded up a little video of a datalog test session. 2nd to 3rd gear roll with 8 psi boost, 11.2:1 AFR, 16° timing. The stall shoots to 5,900 and the tires break loose but at least it sounds cool. Should be ready for the 1/8 mile dragstrip this coming weekend but I don't have real high ET expectations considering the high stall problem.

 

[TomM]

Ohhhh....that sounds nasty.....good luck getting that puppy to hook, converter or not...... :devil:

Excellent job..... :yes:

T,

 

[Dan_Lockwood]

I just reviewed the entire thread and this thing is very coooool...

Nice work and I appreciate you taking time with gradual goals.

Let us know how it does at the strip.

I had converter issues on a streetrod with crank 654hp. After blowing a few converters the guy tells me this one should be the "one" to work like I want.

Well it flashed like yours somewhere in the mid to high 5k range and hit my rev limiter at 6k. I could not feel any shift at all. It seemed very quick, but I'm sure it wasn't. The race guy I took for a ride used the term, "running on the converter". Whatever it was, it was not all that great. I could not drive without slipping. 60 mph at 3500 rpms. I really cooked my trans fluid. My final converter would flash to around 3800 rpm and I could cruise 70 mph at 2700 rpms. I had 4.11, 29" tall tires with a 31% O/D trans with a blown 392 hemi. It was a great ride and I do miss it very much.

You are going to be grinning from ear to ear at the track. It will be very cool when you touch it loose the first time.

Have fun, but be safe. Double check all lines etc. I'm sure you will, just don't want to hear from you next week that this or that happened.

 

[Dub]

Loaded up a little video of a datalog test session. 2nd to 3rd gear roll with 8 psi boost, 11.2:1 AFR, 16° timing. The stall shoots to 5,900 and the tires break loose but at least it sounds cool. Should be ready for the 1/8 mile dragstrip this coming weekend but I don't have real high ET expectations considering the high stall problem.

http://www.youtube.com/watch?v=CJnAbmC0NTU&feature=g-all-u

Dang!!!!! Research Park?

 

[chevy406]

Dan - I love it when people like you stop by to give encouragement and advice. While I have been messing around on the dragstrip with different versions of my Nova for the past 22 years it simply has not been at this level before. Upgrading the front subframe to coilover, tubular control arms, rack & pinnion, and Wilwood brakes should help stability at higher MPH. But I'll also be sure to double check fluid lines, steering connections, and suspension fasteners. It's not a successful race day unless you make it back home.

Dub - you are close. That video was from the industrial park near the Toyota engine plant.

I am making plans to step up to a 9½" PTC converter soon. But I'll have to liquidate some of my left over parts to help finance that. For tonight just trying to get the fuel gauge working again.

 

[chevy406]

Well I already found the first weak link, and that was even before bolting on sticky tires. I took a co-worker for a short acceleration test and busted 2 teeth off the pinion gear. I was already considering dropping my 3.73 gears for something more highway friendly so it isn't a huge disappointment. I have a set of 3.08 gears coming. My long term plan is to save up and buy a more robust differential to replace the 10 bolt.