"Old" H-O TurboForce 400 makes 744lb-ft, 537HP
 

If you haven't seen it yet, check out this article in the current issue of Car Craft magazine. It is also online at:

http://www.carcraft.com/techarticles...ild/index.html

744lb-ft@3400, 537HP@4400

Ken Crocie told me about this build, the testing problems and fixes a few months ago. You can see that it is pretty much identical to the original H-O TurboForce shown here:

http://www.originalho.com/TurboForce.html

Don't ask: the "revival" project is done with no plans for commercial resale, but the I still own the "TurboForce Revival" Bird and there are a few others around, some Machos, some not.

I notice it says the engine needed a cam button to prevent cam walk with the roller:rolleyes: i wonder if that's just a generic Chebby caption.

I'd like to see that setup with a big intercooler.

No cam button of course.
 

Obviously, gotta be a generic caption!

You'll note that there is room for a custom intercooler in place of where the A/C compressor usually would live. I thought about installing one during the early stages of the revival project, but once we could not locate the pressure hat ("bonnet") tooling, I dropped any grandiose plans.

Its good to see the kit on the dyno. It could use a much larger turbo and meth injection would help. 60mm is tiny on that large of an engine, but it still made very good numbers!

It's a shame about the hat tooling. The engine looks awesome.
Will it be installed in a car?

Installed? According to Ken it depends on the owner's health. Right now, probably no, as I understand it. It is a 4-speed car anyway, so that would be a handful in the best of situations.

Unfortunately, a "much larger turbo" will NOT fit in the P-side confines of a stock chassis of a Gen-2 Firebird and the space constraints of the timing cover and fan on the D-side. Remember, the TurboForce kit was designed and sold as a bolt-on setup which fit with ALL accessories including A/C but excluding the HD alternator (due to the idler pulley).

We used to sell a water injection (which you could mix with alcohol or whatever you wanted) unit as an option. That did help. With the original Rajay 301E and open exhaust, 15psi boost was usually seen. Of course that would be way off the sweet spot of the turbo map.

Craig.........couldn't a hat from a ProCharger or something like that be used with the turbo force?

Larry,

If you changed to a Holley carb and possibly bulged the hood there are some commercially available choices. For instance, the "Extreme Velocity" hat looked like a good design but it needs a no-choke Holley and a bulged hood for sure.

The T-F hat is the only one I know of that works with a stock configuration QJet and also fits under a Gen-2 Bird hood. And that was the whole point of the TurboForce design.

Nice build up Craig. Thanks for letting us know about it. I am surprised though Ken used such a large arm with that late 70s block. As you know, a blown engine with a rod ratio like that puts a lot of strain on a not so strong block to start with. If that is a numbers matching T/A, that may be a mistake risking the value of the car. I realize it was a customer build and not his own so that was probably the customers decision and he will have to live with it. Hope it stays together and hope the customer understands that.
How many guys have split natually aspirated 400 blocks with 4 1/4" stroke already? let alone a blown version with even more arm?

Steve
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I figured a lot of people would start thinking about re-engineering this thing. Remember-it's a restoration job. I had to use stock numbers matching block , heads, ex. man. etc. So to make it more of a sleeper, I modified the unseen stuff. Why 4-1/2" stroke? Because I could. I couldn't change the block , but fortuneately the 78 stick block is a XX casting which a re-do of the 70-74 thick main casting.I knew i was going to be limited on peak HP because of the turbo size and stock ex, so I went for torque. Too big of a cam-with 489 cid--I don't think so -especially since it provided a 750 RPM idle with 18" vac. Throttle response was instantanious--no noticeable turbo lag. I ran the engine in manual mode on the superflow and saw over 800 lb/ft below 3000 rpm. CC published what was recorded by the superflow computer. My goal was driveability and big power. The car it is installed in has 3.42 gears and a 4/sp.

the XX block is a thick web casting? good to know, i usually never saved anything older than 71 unless it was a 55.

I didn't think it was in a car.
I bet it would fly with a 2.73 gear

Great Job Ken!, I met you at Pontiac Heaven and we talked for a bit about these setups, it was nice to see it in a magazine! We haven't had any trouble with the 4.5 stroke in 400 blocks at all up to 750hp and Boosted version is easier on parts than a high RPM NA deal, and this engine did pretty well and the Owner should be very excited! one day you should talk more about whats needed to use a Q-jet for Blow THrough!, Thanks

Nice job Ken Crocie!
 

Nice job Ken! Nice article too. Probably worth those nearly sleepless nights.

Since this article came out, I have had the chance to show two out-of-state guys who were by my place for other reasons my TurboForce Revival Firebird. Mostly the response was "wow!", particularly when I told them they could buy the current Car Craft and see one just like it, but BETTER.

And just to be clear, Ken did ALL the work and sorting out on this one. I am only trying to answer design and original engineering and manufacturing questions, which was my main involvement, along with Ken, back in the late 1970s. Of course "TurboForce Revival Project" questions too.

Craig

440GP69: U probably talked to Craig @ Pontiac Heaven about turbos, since I've never been there.

Soon as I figure out how, I post the TQ and HP curves. You have never seen one like this

Yes, the late hi-po (TA 6.6) block is much stronger than the std 77-78 400 block.

Great write up, and very nice numbers working within some very tight constraints.

Quote:
Originally Posted by KEN CROCIE
The car it is installed in has 3.42 gears and a 4/sp.

I didn't think it was in a car.
I bet it would fly with a 2.73 gear
================================================== =======
Ditto, and add this thought: I'd like to see a chart of Stock-steel Ring//Pinion Strength (12-Bolt, 10-Bolt 8.2//8.5) to figure where the Pinion-ratios reveal the weak Pinion or the weak Ring gear when installed for Race.
In other words: I suspect a 3.31:1 is much stronger than a 2.73:1 (pinion susceptible)or a 4.56:1 (Ring susceptible)....stock steel gears.

I am probably wrong here but when looking at that picture with the turbo, are the spark plug wires on correctly?? 18436572 something looks wrong, i see no.2 wire and follow it to the front of motor now i see the boot to no.2 but now look at 6 & 5 wire,s?? Its probably just me.

Your right! I met Craig, Good Guy!

Ken- Is it just me, or does the first pic in Car Craft show a vac. line hooked to a blowoff valve, and the last pic seems to show a pipe w/o a blowoff valve?

Craig- Do you have access to another T F hat? I ask because Ace from PPR could probably have them made inexpensively. He had mentioned before that he could copy/reproduce the old Fire Am oil pan, etc. This may be a good option.
Also, I was thinking (I know, bad idea)... why couldn't you flip the exhaust manifolds L/R and get the dumps toward the front of the car? Less pipe to deal with, and maybe (???) more room for a turbo (or two ;) ).

Here
http://image.carcraft.com/f/techarti...ine_build+.jpg

and here
http://image.carcraft.com/f/26726302...ine_build+.jpg

Probably because Ken has been to the dyno many times getting all of the bugs worked out for the customer. The valve you mention is actually a "wastegate" which controls exhaust volume to the turbocharger vs a blow off valve which is normally used to reduce surge on a quick back-out of the throttle on a blow thru system.

Tom Vaught

Man that's a clean shop and dyno room floor!

Originally, the lack of T-F hat tooling was the show stopper. But later, having seen the experience of Tribal Tubes (repop of H-O Tri-Y headers, not done by me) convinced me that if there was not a market for 25 sets of specialty headers at a few hundred dollars per, then there certainly was not a market for 25 repopped T-F at several thousand dollars per, regardless of how cheap a repopped bonnet would be.

If you flip the exhausts manifolds, then the outlets dump right on top of the cross member. The T-F configuration works just fine since there is NO turbo lag and almost no surgery required to the chassis. I built a custom twin turbo in a Gen-2 Bird once and it violated the "must fit with all accessories" design rule.

Tom,
Thanks for the clarification. I thought they were the same thing w/ different names. I understand what you mean.

Craig-
On the flipping the manifolds- gotcha. I wasn't sure it they would dump on the xmember or not. On the Tri-Y's- I own a pair. I gave him cash and took my headers. No waiting. Most weren't so fortunate. That was a bad deal for all involved.
Also, does the T F bonnet fit a Holley w/ a choke tower or is it strictly Q-Jet?

The fuel bowl on the front end of the Holley interferes with with the inlet on the T-F bonnet, so the bonnet is QJet only. It will fit a Chebbie variant with a little work though.

Very interesting Quadrajet issues and solutions on page 3.

The last version of the bonnet had clearence cast in for the right angle chevy fuel inlet. (Craig: think Ernie Kralick) We needed that for the H-O Camaro 350 kit. To work on a Holley or AFB , a spacer of about 1-1/4" is needed between the carb and bonnet Plus a center stud mounting hole. I plan to do some testing with various aftermaket blow-thru bonnets including the T-F on my next turbo engine ( single 76MM turbo, 462 cid, single blow thru carb, HC-02 w/ Rhoads/BME rods)

1st pix has the final waste gate location. Originally (2nd pix) the waste gate(a smaller Turbonetics as originally optionally used with the H-O T-F kits) was on the pass side near the oil filter. The small wastegate was the source of the "whoosh" refered to in the article.It went wide open at the crack of the secondaries and stayed there and the boost just climbed , out of control

For those of you who have not heard one, a wastegate sounds like an air nozzle being opened, rather than an exhaust type noise which you might expect.

NICE
 

just a question,
would it be better if the o2 sensor was installed after the turbo, like in a down pipe or exhaust pipe?
verry nice setup, i can remember looking at my dad's HO catalog a long time ago and thinking it would be cool to have a turbo car.
i ended up owening a couple of fast 86 & 87 buicks, and the decided to boost my bird.
now i have a procharger and an 8second car, you got to love boost!!!:D

I couldn't do that on the dyno. The O2 would be too close to the atmosphere, possibly giving a false reading.. Tom V might have an answer for a road going application.

power curve

Holy Crap-i did it!

Man, the power is as flat as IOWA. That should be a real driver.

Course the real secret is Kenny's new wastegate. The new much better wastegate is truncating the power all the way across the HP band. If he turned the boost up it would be just as flat BUT at a higher level. More boost, again a higher level of HP.

Really Nice Job Ken C.

as far the othe O2 sensor goes, as long as you are not running excessive exhaust temps you can keep the O2 sensor in the plumbing in front of the turbo. The Turbo will take exhaust heat out of the system and protect the O2 but after the turbo on a single turbo deal will MASK lean cylinders. Better to use 2 O2 bungs and swap the sensor side for side BEFORE the turbo to get real air/fuel readings side for side. JMO

Tom Vaught

Day-um!! That thing ought to move the ol' T/A down the road!!

If you can hook up, that is!! ;)

Boost on a Pontiac = :D

thanks Tom for the input,
we are doing a single deal in the futer, probably later than sooner.