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Blow through turbo, again...


Guest JAMIE T

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I would like to see the whole assembley. For some research. Mabe there should be a sticky made up for blowthrough. I also have a design for twin turbo blowthrough using webber cabs. NOT tripple doubles but double tripples. I already have the carbs from another mid 70's twin turbo car. These webbers are for turbo charging!! What I need is the twin turbo exhaust manifold that TonyD posted up with. I have the pic but I'm not shure if its fotochoped or not. I'm shure someone has a TT exhaust mani or can make me one for a pair of GT25's...mmmmmmmmmm twin boost!!!!!!!

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there was one for sale not long ago in fs section. Problem is they where made for rhd cars. They might not fit with are steering rack.

 

there is nothing more to the tank really except a block off plate to cover what i showed you and a y inlet pipe.

 

These tanks are not cheap and many of us dont want to disclose much about them ;)

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You could also go the route that many diesel tuners go for twin turbo. You can use a single turbine exhaust manifold or header and hook up one GT25 then have a T3 flange connected to the downpipe of the first GT25 and hook up the second GT25 T3 flange. You also run the compressor discharge from 1st turbine to the intake of the second turbine so you only have to run one large air cleaner. They run in a series but still getting the boost and horsepower gains of twin turbo without finding a special twin turbo header or manifold. A popular B&D set up for many diesel trucks. The one in the picture is for the cummins straight-six turbo diesel engine like the one in the Dodge Ram 2500.

turbo_side.jpg

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Wow that is the worst idea i have ever heard. Not only is it bass ackwards there is no room in l28 compartment for all that craziness. Let me tell you why that fails outside of lack of room. Disel motors are not as prone to knock as gas engines. They knock in the re native forum. I have seen stock trucks at work creep to 40lbs and run fine. Buy the time you rigged some dinky ♥♥♥♥ on a l28 to turn 15-18psi you would have the same amount of money to have a twin mani made. That is some hillbilly crap and i live in the sticks of wisconsin. Completely the wrong idea why would you pump 1,400 degree air into a inlet of another turbo.

 

I have truley given up on this thread. WOW is all i can say.

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I didn't specifically mention using the actual pictured diesel turbines in a gas engine however you could if your engine was built to handle that level of boost. Of course that set up would require specific fabrication to place the turbines and pipes not to interfere with the steering shaft of left hand drive Z cars. Give a logical reason why a sequential turbo set up like I stated wouldn't work? Provided you select the proper twin turbine size appropriate for the level of mods in your particular car. In addition to that, you could essentially mount a turbocharger anywhere you like so you could essentially have a triple or quad turbo car if you so desire and have the engine compression and quality of fuel to run that set up. Think outside the box my friend before you insult people's ideas....

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Becasue sequnetial ♥♥♥♥ FAILS How do i know this becasue i have removed 13 seq setups from 3rd gen rx7s and 4 porsche 911's. they suck they never or if they do for short term work right. Its a over complicated design that fails in 90 percent of applications.

But dont listen the guy who worked at mazda for years. I have seen every seq nightmare you can think and dont blame the parts, Mazda got sued for lifting the design from the 911.

The l28 would be pretty worthless anyway in a twin setup 3 cyl driving a charger get out of town talk about never in efficiency range of the compressor map.

Or turbos so small you wouldn't care.

Let alone doing all this on carbs.

 

The theroy of seq twins is sound, one small to driver the large removing lag. But if youre turbo is mapped right you wont have lag. I have driven pleny of cars thst made full boost at 1,700.

 

I will let TonyD elaborate on why they Fail

 

Think outside the box lol.......i build 4 rotor and 3 rotor engines from scratch perphial port 4,000 rpm idleing 14,000 rpm redline lol

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Very impressive, thanks for all your advice since we started these posts. I have been thinking of trying a rotary in an early Z body for quite some time. The ungodly rpm potential, the light weight of the rotary engine and unbelievable power they can put out with large turbochargers. There was this guy in Japan I used to race against in Yokohama in 1999. He had red FC3 with a highly modified 13b with a HKS T51 SPL BB turbine in it and his car was a monster I would get him some races and he would get me sometimes if I made a shift error of any kind. I had a T51 SPL big single turbine in my R32 GTR at the time. Its amazing how much the 1300 cc 13b rotary can do with such a small displacement and six compression strokes per engine revolution. Now the only thing I am wondering is where to find a 4 barrel intake manifold for a 13b engine that would fit american Holly, Demon or Edelbrock carburators on it for blow through applications? I have seen several successful weber down draft combos for 12A and 13B however, have not seen american carbs on the 13B yet.

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I rather like the idea of Twin charging. Supercharge at low end with a bypass pipe and electromagnetic clutch. Once the turbo spools into its efficiency range, the bypass pipe cuts out the supercharger, and kicks in the turbo charger, and disengages the supercharger.

 

A local speed shop that goes by FAT (Forced Air Techologies) built a subaru with that setup

http://www.forcedairtechnologies.com/2009/07/19/sti-compound-charged-gt35r-amg-supercharger/

 

they're also finishing off a Twin Turbo/Supercharged setup that seems to work in the same way.

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Thanks for the Racing Beat link. I like that holley / supercharger rotary set up in your picture, how close are you to shreading tires and dragstrips with it? A rotary supercharger set up with 14,000 + rpm potential.... Just makes me think about a large ball bearing T4 blowing through the carburator into that supercharger. Then I would have to consider the maximum boost a rotary could handle and still keep its apex seals, rotors and housings intact...What kind of side or bridge porting would have to be done to the rotary for that type of extreme boost... Supercharger boost is right off the line and stabilizes around 5,000 or so rpm, most large T4 turbines take around 5,000/6,000 rpm to reach their peak and the rotary engine can spin up to 14,000 rpm. Thats around 9,000 rpms of T4 max boost potential to play with in each gear before reaching redline. The supercharger has the boost off the line strong until around 5,000 rpm when the T4 takes over...Traction for that kind of power would have to come from some serious soft compound slicks. I wonder if that idea has been tried yet? If not, well that's the next one I will attempt when I source a cheap S30-Z, a used 13BT and a bunch of other parts.... One of the reasons I like blow through is that I do not need computers or complicated programs to change fuel settings. Just another set of jets, adjust the regulator monitor boost, egt and afr and try again. There is a Ford GT that has a mid engine supercharged V-8 that was modified by Hennessey with additional twin turbo kit feeding the supercharger and was quite powerful. http://www.hennesseyperformance.com/ItemDetail.php?Item_ID=230&cart=lAIBNXfK&DoThis=Ford+GT&ActionReq=Where The redlines for most V-8 engines are not even close to that of rotaries. What are your thoughts?

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That motor is a stock port 12a it made 236 at the wheels. That car is long gone it was my test mule for supercharging and custom turbo setups. It was rotted on the under side in the bin areas. no saving it.

 

To keep a rotary together with boost requires lots of things one piece apex seals for one....but they have a tendency to chatter the housings. R5 nitraded plates....tons of oil mods to be stable above 10 grand. The average rotary i build is not as wild as the 4 rotors but i do throw together alot of bridgeported 13bs. Average power in na trim is around 230

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yetter, how much do four rotor shafts go for? I've only ever heard of "a buddy of a buddy of a buddy etc" that ordered one, but if you've gotten them direct, how much do they go for. I've been thinking of rotaries alot recently, and while I'm not going to do a four rotor within the next decade or two, I would love to know how much $$$ that would go for....

 

hijack>

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Garett is making integral dual turbos with unitized castings more for flow required at boost. They also have twin compressors on single turbine drives that have CR of over 3:1 meaning 45psi. The deal is flow, you need a compressor of X size to flow X CFM and there is no way around it. Unless you run tandem compressors from the same turbine...

 

And that kind of blows the twin turbo argument in the water...because when those super-high flow turbos show up on the aftermarket you will have a LOT less packaging headaches.

 

Twins on S30's were deriguer in the 80's simply because compressor and turbine wheel technology were not up to the requirements. You needed twins to have any sort of spool on a 600+ HP car. By the mid 90's they had passed into the history books simply because of the advances in 5 axis machining. The ability to lower boost threshold to lower rpms is materials and bearing related. BB Turbos are running 500 rpms lower thresholds than the older sleeve bearing designs, ceramic and titanium lower inertia and are stronger, 5Axis milling means thinner blades so more air flows through at the same speeds as before... I could get 17psi running a .43 housing at 1700rpms (1982 Technology), and it was all in by 5500, but really the stock cam worked in conjunction with that as well. I would be really interested with a larger wastegate hole (or external gate) and the new compressor wheels what I could do with that same setup today... I suspect 6500 rpm power peak, and that same boost available from 1200rpms with far more HP potential.

 

The surge curves of the new wheels allow things never before DREAMED of even in the late 80's when the the word came from on high from Moses Bell out of Texas. Well, the bush was burning when I sat agog at the Garrett (Nee Honeywell/Allied Signal) R&D Facility in Lomita and it said unto me: Worship not at the altar of Bell, and learn well the lessons of Turbocharger Research and Development, for it will lead you to a land of smoking and burnouts...

 

I digress... how did this turn into a Rotary Thread? LOL

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The rotary thread came to pass when it was pondered installing rotary engine into an early S30 Z body with supercharger, turbocharger, wicked 4-barrel carburator, whether blow through or draw through. Ideas begging to be explored. The engines are light with high rpm and power potential just waiting to be hybrid in a z body. Two rotor, three rotor or four rotor they're powerplants that scream in their own unique tone and challenge all that tune it to find ways to keep it all on the ground and in track.

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  • 1 month later...

So, to try and bring this back on-topic, Weber 40DCOE's should work just as Dells or Mikunis so long as they've been modified with solid or foam-filled floats, and anything else?

 

Say I've got a stock L28ET currently and I want to do the switch to a triple-carb single turbo blow-through setup; what do I do about the ECU and the rest of the sensors; run standalone?

 

About fuel pressure: lets say I'm running a T3/T4 at 15psi. 15psi plus 4-5lbs is still way less than most modern EFI setups (right?), how big of a fuel pump would be needed?

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