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-   -   my idea for zero turbo lag (https://www.rx7club.com/1st-generation-specific-1979-1985-18/my-idea-zero-turbo-lag-216160/)

The_7 08-19-03 11:45 PM

my idea for zero turbo lag
 
i dont know if this has been done before but i was thinking about it. say you have a tank for pressurized air located in a safe spot. it has inlet hooked to turbo air outlet and outlet hooked to intake manifold. when not racing you can use the turbo to fill and pressurize the tank to full boost pressure. once the tank is fully pressurized, the intake system runs normally. then you have an adjustable controller so that when you push the gas in far enough while going low speed before turbo has kicked in, the stored pressurized air can be used to have low rpm power before the turbo gets to operating speed. what do you guys think?

'85 GSL 302 08-20-03 01:25 AM

Highly impractical

1) You'd need lines that were like 1-2" to get enough air into the manifold to make a difference.

2) You'd need valves that could open and close those large sections fast enough to make the difference

3) You'd have a major problem putting the tank through hundreds of heat cycles over and over again pressurinsing and depressurising it.

4) There are already many systems out there that are easier and probably would work better.


a) Nitrous to overcome the lag
b) Miss-fire systems that kill spark in alternating cylinders durring decel. This puts fuel into the exhaust, which then deatonates on the hot turbine, causing a gas expanse and keeping the turbo spooled.

The_7 08-20-03 01:35 AM

i just intented this to be used only right off the line before the turbo spools for the first time, not between shifts. so you would just use it once per race and then refill it afterwards. even so, it would still be impractical after i thought about it, the tank would add some weight and depending on how much lag you have it would take a pretty hefty tank. its more of just an interesting thought. however it has an advantage over nitrous because you can refill it using the turbo.

that mis fire thing sounds pretty cool, but wouldnt that shorten the life of the turbo?

A-Tech 08-20-03 02:15 AM

apparently lotsa people in japan use it for their uber drift competitions, or I could be talking out of my ass...

FB II 08-20-03 06:38 AM

the misfire way of keeping turbo's spooled is so bad ass! watching huge flames shoot out the exhaust WOO WOOOOOOOOO!

fatboy7 08-20-03 10:33 AM

Anti-lag puts a lot of stress on the turbo. Things het hot pretty quick when you've got combustibles exploding into the turbo. If its too hot, it could melt the turbine, otherwise It'll shorten bearing life considerably. Thats why rally cars use high temperature nickel-steels, Inconel, etc. for they're turbine and housing.

aGoGo 08-20-03 10:38 AM

Miss-firing only for turbo cars?

Junia 08-20-03 11:09 AM

Yes, theres no reason to have a mis-firing system on a N/A motor. theres no turbo lag. I don't think turbo lag is a really big problem nowdays with the newer turbos. They don't lag like some of the older ones from back in the
80's.

AdrenalifeRX7 08-20-03 11:49 AM

You could increase your idle speed. That will reduce the lag somewhat, but it all depends on what turbo you're using and when it begins to spool.

RotaryMotorDisorter 08-20-03 01:01 PM

When the VATN (Variable area turbine nozzle) turbo is avalible, its gonna be nice. No wastegate needed. The responce of the VATN vs. a standard turbine will be cut in half. Pretty cool.

'85 GSL 302 08-21-03 12:01 AM

Yeah, with a small turbo lag is so minimal it's not really an issue. Most race cars though run nasty turbo's because the bigger the turbo the more efficient it is. The mis-fire systems do decrease turbo life but the huge impact they have is to the turbo manifolds. Typical manifolds will only last you about a year before they get distroyed. All you need now is a computer flashing "DANGER TO MANIFOLD!!!" hehehe

mwatson184 08-21-03 12:58 AM

The VATN turbo is available and has been for a couple decades. Look at the s4 TIIs with their twin scroll systems, Peugeot used a garrett VAT in their T16 model in 92, and their are many other examples. However, a wastegate is still needed otherwise how do you prevent overboost??

The bigger the turbo the more efficient it is....not necesarily. Smaller turbos are normaly more efficient at lower boost levels, larger ones at higher boost levels.

The general idea you have is very impractical as stated before. The engine simply consumes too much air. Unless you plan on having a 20 cubic foot pressurized container the compressed air will not be able to make a difference.

-Marques

RotorMotorDriver 08-21-03 04:26 AM

What if you did it the other way around and ran the car off the tank of compressed air, and used the turbo to keep it topped off? Kinda like a surge tank setup for a fuel system.

So when you accelerate, you already have the compressed air waiting to go into the engine, no waiting for the turbo to spool to compress it first. Then once the engine is going fast enough to spool the turbo, it compresses air so it can be stored in the tank again.

~T.J.

AdrenalifeRX7 08-21-03 11:49 AM

Haha..hook a portable tire inflator up to your motor and run it off the cigarette lighter.

The_7 08-21-03 12:40 PM


Haha..hook a portable tire inflator up to your motor and run it off the cigarette lighter.
:rofl:


What if you did it the other way around and ran the car off the tank of compressed air, and used the turbo to keep it topped off? Kinda like a surge tank setup for a fuel system.

So when you accelerate, you already have the compressed air waiting to go into the engine, no waiting for the turbo to spool to compress it first. Then once the engine is going fast enough to spool the turbo, it compresses air so it can be stored in the tank again.
yea, you could have a small tanks already pressurized for an initial boost, and as it gets used the turbo spools and refills& pressurizes it so this way between shifts there would be NO pressure drop, and you would have reduced lag off the line. it wouldnt work as good for the single huge turbos tho....you would go fast and then you would lose all the power and then it would come back lol. but if you used this system with a twin sequential turbo setup it would have almost no lag. also you could combine it with other anti lag technology to help. when i turbo my fb im gonna experiment with that :)

fatboy7 08-21-03 01:40 PM

Do you have any idea how much a motor flows on boost at full tilt? Our rotories move around 100-200 CFM when the turbo starts to spool, and 300-400 CFM at redline, and more depending on the turbo. So to hold enough air to counteract the 1 - 2 sec that the turbo takes to spool from low rpm you'd have to have around 5 ft^3 of storage minimum, roughly a 37 gal storage tank. Not to mention the valving and hose size that would be required to release 37 gal of air quick enough to make a difference.

mattrx7N/A 08-21-03 06:33 PM

Lol, The tank thing would never work. I dont even want start on the "mis-fire" thing. If you want less turbo lag get a ball bearing turbo!

Oh, and all turbine wheels are Inconel.

Pedestrian X 08-21-03 06:39 PM

i have heard something about poeple shooting some naaaawwzzz into the turbo to give it a lil kick start. id take it with a grain of salt though.

The_7 08-21-03 09:47 PM

when i do get my car turboed i dont plan on doing the misfire thing or using the nos since i wont be able to afford an new turbo that soon ;).

fatboy7, so it wouldnt be practical for single turbo setups, what if you had a twin sequential setup where the smaller turbo was small enough to spool really earlier so you wouldnt need such a large tank. so it uses the tank air and then the smaller turbo spools keeping the tank pressurized and then the big turbo spools, so you would have almost no lag, and the tank can also beused to counter act the small pressure drop between shifts. also, what if you had a single turbo setup and had a reasonable sized tanks and had a computer controller so it has a timed release so the turbo spools just as the tanks pressure drops to a certain level, so you wouldnt have power right off the line, but you could have the high end power of a large turbo with the reduced lag of a smaller one :)

fatboy7 08-22-03 01:30 AM

It just seems to me that with the weight needed to add a surge tank of air, the expense of the whole setup, and the time it would take it get something working -- you could have done some R&D, bought several turbos, found a keeper, and be driving faster from day one.

Lag isn't a big deal. It really only has effect low in the RPM range. If you're going to drive fast your most likely to be rev'd up beyond 4k even during the 1st-to-2nd shift. beyond 4-5k lag really isn't an issue.

rototiller1 08-22-03 02:18 AM

The Navy used to use a 3 pound coffee can full of gun powder to start the jets, they had air turbine starters


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