Turbo sizing
Looks like fun Ryan.
Yes, I skimmed the other thread. Guess I missed some of where you addressed that.
You probably put this somewhere else as well- but have you considered a centri supercharger? Like a novi 1200 or 1500? I have a bracket in selling right now on LX forums.
You must be more mature than me- I always want more power. I want the most power I can use in 3rd gear on a road course while rolling into the throttle. If and when I get there, I'll probably then want the same in 4th! Such is the hot rodders natural progression.
I believe I addressed that suggestion with jw97 in the other thread when he made the same suggestion...
I'm familiar with the truck accessory cover. If I were going to run twins it would make a lot of sense to run the exhaust manifolds forward. However, since I'll be running a single turbo and have to run a crossover pipe anyhow it doesn't really serve me any benefit to dump the drivers side in front of the engine and try to cross between the radiator fan and the serpentine belt. It will be tight enough as is without a 3+ inch pipe.
It simply centers around running a single turbo and the necessary pipe routing. I don't really want to run twins or see it as necessary for my hp or spool requirements. As to the desire for more, I don't know about maturity, truth be told this will be the fastest car I've ever driven, much less ridden in. I may eventually end up thinking I want more but I already have a plan for that. Contemplating another build down the road with another early a using a 904 or 727 auto behind a 2.4L turbo. Could do it properly then with a cage, etc. A real race car that could actually make use of that power and would still be unique doing so. However, that's a trip to the moon away. Just want to get this thing running! :burnout: In regards to a centrifugal supercharger, call me silly but I just don't like the concept of a belt driven turbo. I'm not against superchargers by any means, I'd love to run a twin screw or a roots tvs style blower on the hemi, but I simply can't afford to spend 6k for something like that. I'm already putting too much into this car as is. I feel more than confident this turbo can be done very nicely for significantly less than that.
What you're building has been done quite a few times by magazine builds and guys running modern mopars. If you can't find the info you need pm me and get you going in the right direction.
A single 76mm Ebay China turbo will reach those goals. Take it apart when you receive it and make sure you use the proper torque specs and thread lock.
You could spend more on a name brand turbo and not have those worries.
If you went twins you could run twin 57mm but I would go for the twin 61 route. You won't lose much spool time if any and your ceiling will be well beyond what you're describing.
I wouldn't push the stock motor passed 500rwhp. Most of the reading I've done suggest the pistons won't last very long above that power level. That will be in the 8-10lb of boost range.
Hi MattP,
I know... The magazines just kill me because they rarely address issues of interest to people who aren't strictly looking for max hp/torque in their weekend bracket racer. Like spool time, tuning, sizing, intercooler performance, lessons learned, the list goes on and on. That said, I have learned quite a bit from
this article (linked in my other thread as I already mentioned), but that was mostly in what power levels to expect, etc. It did turn me on to Ebay intercoolers from cxracing which I am currently researching sun up to sun down. I'm really excited about where it looks like this build is going and I don't see any clear complications, just really looking for anyone's experience in sizing a turbo on these engines. Thanks for weighing in.
I learned a thumb(?) rule(???) inducer(mm) x inducer(mm) / 6 = Max hp for compressor.
lets say a 76mm china turbo. 76x76/6 = 960HP.
if you going stock bottom end, I would put in a bigger camshaft in it with much overlap and tight LSA to get away with cylinder pressure. You do not get alot of power in the low rpms, but much more fun i the top, and its easier for the engine! its the cylinder pressure that destroy the engine!
I believe there is no such thing as a "turbo" camshaft. you may turbo any camshaft! at 14psi, your power output is aprox doubled over NA power. build yourself a nice crisp 400hp engine and turbo it.7psi - 600hp 14psi - 800hp...
good luck! :-)
That's an interesting rule of thumb I've yet to come across. I'll have to look into that. As for cylinder pressures, I expect they'll be high and I'm hopeful to run quite a bit of timing to encourage some low rpm torque for normal driving outside of boost. I suspect E85 will assist in meeting those requirements with relative ease.
So far, I've been recommended by:
Stage6motorsports - Precision PT6766 CEA, T4 .81 or .96
PWR - T4 67mm turbo, specifically the Borg Warner S300-66 ETT with a 1.0 a/r. PWR also recommended a 6.1 cam with aftermarket springs or 6.1 exh springs all around and forged pushrods.
Inertia Motorsports - Really only weighed in to tell me that they'd recommend a stock computer or I'd just blow it up, really disappointed in that answer to be honest. Sounds more like friendly marketing than an honest answer. Numerous hemi's run on aftermarket ecm's? Maybe just a lack of experience with them...
Precision Turbo - PT7175 CEA with T4 .81 a/r for quicker spool or a .96 for slightly slower spool. They expected 2800-3200 rpm spool with the .81 a/r housing, the .96 would be 3-400 rpm slower.
I will say that I'm not in the market for an expensive ball bearing flux capacitor turbo... The precision recommendations are definitely higher on the money tree, the borg warner extended tip tech seems interesting with the wider maps and they are lower priced from what I'm finding. 66-71mm is the current inducer range recommended, we'll see what forcedinductions.com responds with as well as turbonetics, I shudder to even think what they'll recommend price-wise.
-Ryan
