7 replies to this topic

[klevliend]

Hey all, I've got a lot of good info from these forums over the years and am hoping for a little more!

I need some help selecting a torque convertor. Its to suit a 308 with Turbo 400 in a HJ holden panelvan with 3.08 gears. The engine is a bit of an unknown, a used running engine I bought. What I do know is that it has a Crane 286 cam (or near enough it makes no difference),  early heads with no porting, unsure if it has bigger valves, and aftermarket US pistons (so I assume its not low comp). It previously had a edelbrock manifold and demon carb but I'll be running the stock HJ manifold and rochester carb.

 

My question is, what torque convertor would suit? Or perhaps, does anyone have advice on choosing a torque convertor?

I got a quote TCE torque convertors. They were really really helpful and pretty upfront and honest that their torque convertors are overkill for what I need and that I could find something off the shelf for less. They recommended a 9.5" 2500 stall speed convertor, which I'd consider pretty good advice.

Adding to the list of questions, what's the 9.5" refer to? Will all torque convertors to suit a 308 need to be 9.5" or is that a custom thing to affect centrifugal weight or something. Will any turbo 400 convertor work or will it need to suit a 308?

 

Any and all advice welcome thanks!

[yel327]

Talk to Dominator. Send them the engine specs, exhaust, diff ratio, tyre size, vehicle use etc. They’ll tell you exactly what you need and make it for you.

[rexy]

A couple of questions.

 

Are you doing all the mechanical work yourself?

Do you already have a converter?

What is the intended use of the car?

 

If you have a stock converter and can do the work yourself for a car that will see lots of 80km/h plus cruising I would be tempted to put it together and see how you go.

[klevliend]

Thanks Yel327, Dominator Torque Convertors are not too far from me so I will drop in and see if they can help.

And Rexy I am doing all the mechanical work myself. I've done enough before that I'm confident I can do it, just that autos are new to me.

 

I have what I believe is a stock convertor, it came with the trans and is untested though I assume running. I've done a bunch of reading and found quite a few on forums who say the a stock convertor will work with a 286 cam, but that isn't ideal hunt at the lights, pushing against the brakes. I don't want to pull it apart just to change the convertor so am happy to spend the money and know that its done right. I live in Melbourne so stop start traffic is the norm.

 

The car is predominantly a cruiser, though if I can make it go faster I wont say no. I'd probably put it down the 1/4 mile at a soft drag and drive event like the Hardass 1000 and be happy to run a 15 sec pass.

[Cook]

Hi, I am running 355 stroker with t400 and 9inch. At the time I went to TCT in Springvale on recommendation from a couple of people, and they were quite helpful and reasonably priced. I'm not pushing the car by any means but all running fine.That was some time ago but may be an option. Cheers Ron 

[LXCHEV]

I would happily have faith in any of the big converter companies in Melbourne (we're actually really spoiled for choice);

• TCE
• TCT
• Dominator

Any of those big 3 will take your specs and recommend / provide something suitable.

 

If you already have a stock converter - they could also use that as a starting point, and possibly modify it slightly (and could save you some coin). For example - a stock converter is probably somewhere around ~1600 to 1800 RPM stall. If the plan is to not stray very far from that - perhaps going up to 2500 RPM - then it should be fine. Going any larger, they'll likely need to use an alternate converter to start with.

 

To answer your other question - the 9.5" refers to the physical diameter of the converter itself. Eg. 8", 9", 10", 12", 13" etc. Smaller converters versus larger converters - lots of talking points hiding in there too:

 

Larger converters (eg. 12") - are commonly found in stock or mild applications - and can provide better economy / smoother operation.

 

Smaller converters (eg. 8" - 10") - will typically be made with higher stall speeds (hence the term hi-stall) and provide performance benefits - faster acceleration, greater torque multiplication at high RPMs, and are more suited for aggressive camshafts as they provide much more slip at idle.

[yel327]

I got one of Dominator in the last year. I have a stock TH350 with a B&M shift kit in it. Going into a HK GTS with a 3.0:1 9" and 215/60/15 tyres. Engine is a stock flat tappet 9.3:1 230hp 4BBL 305 Mercruiser engine. Has a Holley Sniper and Hyperspark. Twin 2.5" system through resonators into a single HK style muffler.

 

They recommended a 2100-2300rpm stall Streaker converter. It was $550 plus GST. Told me it'd be perfect for that sort of engine, but useless when I change it out to the 385ci engine later, which is fine as it'll have a new box built for it anyway.

[rexy]

I cant recommend TCT. They cocked up the split and clean on the converter behind the LS in the LJ and wouldn’t admit their mistake until they were forced to.

 

Dominator were fantastic every time I have used them. A bit slower to get stuff done because they are bloody good!

 

My HQ ute is a BBC T400 9 inch combo. 

 

It started as a mildish 502 with 2500 rpm converter and 3.0 rear gears. Drove quite nicely but wasn't quick enough for my liking. Dominator remodded their converter to 3000 stall and it was much nicer (and felt a lot quicker).

 

A while later when the ute didn't feel fast anymore - yes, this will happen to you! - I upgraded to a 572 with a giant cam. I left the old 3000 converter in it cos I was interested to see how it behaved.  It was certainly faster than the old engine but the stall was about 1000 rpm below peak torque and it was a frustrating drive waiting for the car to hit the big power rpm range.

 

I asked dominator if they could redo the converter again but it needed a new build smaller diameter unit to get the 4000 stall/flash speed I wanted.

Fitting this transformed the car. Felt like it had gained 300hp. Never again will I have too small a converter in a fun car.

 

As all of my driving is suburban and I don't do that many kilometres a year it doesn't bother me that the converter never locks up.

 

 

As your engine is a bit of an unknown it would be most helpful if you could get it dynoed, then that would take all the guesswork out of selecting the stall/flash speed.

 

I had a very similar build 308 to yours in my old LX a million years ago. It made 210 hp at the tyres and the cam came in at about 3200 and was done by 5600.

 

See you on the street!