Don't think two will fit in my engine compartment. i'm running a stock block also. At some point would like to pic you,and HOTMPR'S brain. 64 Dart wagon BB, push button trans.





Ray

Dizuster couple of questions.

Would the Dorman replacement magnum manifolds be okay?

At your power level/turbo what type of cam would you recommend solid flat, roller hyd/solid given the choice and what sort of duration and split/lift?

Dorman stuff is perfectly acceptable...no reason why they won't work.

My cam is pretty small. 230/235@.050", .540" lift on a 112lsa. Mine is a hydraulic roller, but I started with a roller block so it was cheap and easy to do. If I had an older block I'd use a flat solid. Turbo cams can be pretty mild and still make big power, so no need to do anything too crazy with it.

This is a good thread. I too am trying to learn about turbos. My 360 magnum spun a rod bearing and needs a rebuild. So I'm in the market for an upgrade.

Dizuster do you have a build thread or pics of your engine on moparts somewhere. I'd love to see as much as I could of your car.

Me too, I'm thinking I have a 400ci sitting in the garage........
Dan

rtt





I run the Dorman replacement manifolds on my turbo car. They definitely arnt as nice of a casting as the oem ones, but they've been holding up fine for 3 years now.

Not including junkyard turbo builds, it always seems to be that when turbo'ing v8 motors to go for maximum power, people tend to be to conservative on the turbo size. I know the turbo manufactures put the HP ranges on the turbos and sometimes it looks like a certain turbo would be way too big, but in real world, you have to really oversize the turbo to get big power results.
I agree the cam doesn't have to be overly aggressive either, more lift is good though.
I got most of my turbocharging experience in Japan, whats considered right for a motor over there is seen as gargantuan over here. Their favorite turbo for 2-3 litre class motors are turbos in the single 72-76mm range even for street car use(500-800 rwhp, pump gas). Add some more performance parts like flat shift transmissions, built motors etc and the turbo's go bigger yet. I run a 81mm turbo on a street car with a 2 litre motor.
I've watched a lot of turbo v8 builds on youtube and the power always seems kinda low when people are turbocharging 5 litre or bigger motors. I want to try a 400 B engine turbo project, but I don't really have any kind of chassis to put in.. I have a motor and pile of turbos laying around..
If I applied the Japanese tuning shop methods to it, it would be like this:
-shortest runner turbo manifolds possible(long manifolds kill power and increase spool time)
-Largest intercooler piping and intercooler I could get my hands on( this doesn't make lag, it cuts lag, it lets the engine breath to spool the turbo)
-port fuel injection with staged injection
-largest throttle body possible
-run twin 80mm minumum
-build engine to rev to 7000 rpm
-tall rear end gear
-6 spd close ratio transmission with flat shifting or 5 spd auto.
-best breathing heads possible
-Size the turbine so the W/G is wide open at target boost.
-low compression ratio around 8:1 (increased Mass flow rate, engine acts bigger than a higher compression motor)
I should start looking for a good D-150 to do the 400 build on with twin GT45's.. Maybe after I move shop to somewhere else.

I agree 100% with everything in that post until you get to the trans part.

Whats your thoughts on the transmission? After switching to a close ratio 6sp dog box, I'd never go back to a normal manual 5 speed or less transmission. The car is so much quicker flat shifting under boost without having to respool the turbo every shift like on OEM synchro'd boxes..Landing back right into the power band really makes the car faster. I went from keeping pace with modded turbo porsches to blowing right by them.
I suppose in drag racing minimizing your shifting reduces Et.

I am referring to drag racing. Road racing a turbo v8 is a nightmare. I have a perfect example of that sitting in my shop right now. WAY more power than any road race car needs or could use. 6 speed manual gear box. The car is horrible for road racing, and horrible for drag racing. It is now going to be used for top speed runs at various events. Anyway, when you are talking about V8s with large turbos, viable transmission choices dwindle. The broad tq developed by a turbo 8cyl simply doesn't need that many progressive gears to get it to move along. Doing so only makes the car more complicated and delicate.

The reason those little 2-3 liter motors can run such big turbos is RPM. They spin 9-10000 rpm. A lot different than a big block that goes 65-7000.

I've tried a lot of turbos on a lot of cars. Heck, I've tried a lot of turbos on my own car. I have learned that going bigger than suggested has always worked out better.

On my last setup peak power was 5500 rpm with 7200 rpm shift point. Most of the import 6's have a 4k-7k power band. The only cars I have seen that run over 9000 rpm are non turbo rotary motors.

Most of my experience comes pre-production development type applications, but our guideline is the pre-turbine hotside volume should not exceed 10% of the engine displacement. Granted this has a larger impact on street drive and manual trans cars, as a proper converter will allow you to spool regardless, however, turbines need both heat and flow, so the more heat you can push through the turbo, the better.

This may sound counter intuitive, but a compressor wheel that is to small for a specific application can cause more back pressure in the exhaust than a poor choice of turbine wheel/ A/R.

I don't see how that's possible? 360CID motor x 10% = 36CID. 2" pipe has a sq area of 3.13", meaning that you'd only get 11.5" of linear pipe to work with? You can't even connect both sides of the motor with 11.5" inches of pipe?

Did I misunderstand what you're saying, or is this more for single turbo 4 banger stuff?

More for single turbo 4 banger/twin turbo 6 type stuff, the point being, minimizing hotside volume can improve transient response. Not really a factor on drag stuff with loose-ish converters.

Agreed, the shorter the better. Some of the modern V8 diesels have the exhaust exiting into the valley of the engine with the turbocharger mounted there to reduce the pre-turbine exhaust volume too.

The best performing manifolds for import guys has always been the HKS or some of the Greddy stuff, they made their manifolds a different way(stake formed or cast) to minimize hotside runner length. Other people for the same motors used preformed fittings, and their manifold volumes and size were dictated by how their materials went together rather than what the turbo system really wanted.
The success of the HKS, Greddy, blitz etc turbos on imports was also because they did tons of R&D on Turbine/compressor balance to see what works best for the 2-3 litre class motors, their target market. Even though there are more efficient wheels out there now, nobody just off the shelf picking of the newer turbos is surpassing what was done with the now old HKS designs, which were Garrett centers sections altered and trimmed to fit HKS turbines and compressor housings.
Be nice if a big North American company would do the same for V8 applications, take a lot of the guess work away. A lot of people do get good results by buying a few hot sides and getting close, but how optimized are these setups? I don't think there is anything out there like a specifically trimmed turbo for 5-6 litre motors @ xxx rwhp etc.
On a sb or BB dodge the best option might be OEM style manifolds, rather than inverted long tubes. I can't remember if the BB manifolds are symetrical so they could just be turned upside down.




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Oh cool. My buddy runs a turbo 4cyl eagle talon and hes in the 9000 range with a 80mm I believe..