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PostPosted: Wed Sep 28, 2011 7:37 pm 
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any i know if there is any whay to make the turbo spool up quicker?

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PostPosted: Wed Sep 28, 2011 7:53 pm 
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a little bit of N2O will help

or for a real proper job an eaton or rootes supercharger

ballbearing turbos of a suitable size are allso good


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PostPosted: Wed Sep 28, 2011 8:07 pm 
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Hi,

you could try a ceramic coating like zircotec on the turbo and the parts before but not after to get a bigger temp. difference on the turbine

you can also ask the märkisches werk to build titan internals for you

http://www.mwracing.eu/Products/Turbo_C ... heels.aspx

but i'am pretty sure that i doesn't want to know the price :lol:

greetz

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PostPosted: Wed Sep 28, 2011 8:22 pm 
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two_OH_five wrote:
a little bit of N2O will help

or for a real proper job an eaton or rootes supercharger

ballbearing turbos of a suitable size are allso good

Electric turbo systems are also now available off the shelf. Coming to F1 in 2013 but you could be ahead of the curve :D

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1994 Toyota Celica GT-Four ST205WRC JDM 269bhp @ 0.9bar
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PostPosted: Wed Sep 28, 2011 8:28 pm 
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I am pretty sure very shortly a major manufacture is releasing a car with electric turbo. I thought it was BMW, but I need to find the article to be sure. I could have sworn it was twin turbo, one standard and one electric.

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PostPosted: Wed Sep 28, 2011 10:42 pm 
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ALS

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PostPosted: Thu Sep 29, 2011 2:00 pm 
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Hi,

Meurz wrote:
ALS


lol :lol:
but works :)

greetz

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PostPosted: Thu Sep 29, 2011 5:38 pm 
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been shown this

http://www.google.gr/imgres?q=quick+spo ... 9,r:11,s:0

http://www.spracingonline.com/store/Sou ... Valve/3659

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PostPosted: Thu Sep 29, 2011 10:33 pm 
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Act like Tvis, velocity vs flow

but as the CT2x (hybrid or not) is a twin entry setup included Ex manifold we can't use this


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PostPosted: Sun Oct 02, 2011 8:46 pm 
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The boost from a turbo comes from the compressor, and the compressor is driven by the turbine. The turbine requires energy in the exhaust gas to spin, so what you want is more energy lower down the rev range if you want to see boost earlier.

This energy manifests itself as thermal and kinetic energy. By increasing either of those things you in theory will spin the turbine faster at a given engine RPM - or produce the same boost pressure at a lower point in the RPM range.

It's possible to increase the temperature by lagging the manifold with wrap or by ceramic coating it. Both methods help to keep the heat energy within the manifold metal work and stop it escaping to atmosphere - the downside is that you can overheat the metal which can lead to localised hotspots/uneven expansion and cracking.

Another way to increase the temperature is to play with the ignition timing. When the spark plugs fire the fuel/air mixture doesn’t immediately ignite and burn, it’s a relatively slow process where the plug starts a ‘kernel’ of the mixture burning and it then travels outwards over the surface of the piston at a speed of around 2 metres per second. By retarding the ignition sequence so that the plugs don’t fire till later the mixture can still be mid-burn as it leaves the engine and heads off down towards the turbo. The downside to this method is that you're also robbing the engine of power so whilst you may start to see an increase in boost sooner the engine will feel 'flat' at the same time due to incomplete combustion.
An alternative to the more fuel method is to use less fuel. By using the correct ignition timing but leaning out the mixture the exhaust gas temps will rise considerably. This is the mapping strategy I prefer to use to get my turbo spooling so early (people who have been in my car on track are surprised by how early it spools, it's almost feels normally aspirated). My standard engine has done 15,000 miles since I fitted it and is still going strong and I use 13.5-13.8:1 AFR in my spool region to get the turbo on song. The leaner mixture will require the timing to be carefully mapped as the engine will be more prone to ‘knock’ thanks to the higher in-cylinder temperatures produced by the lean mixture.

Exhaust cam timing can also be played with, but in my experience an engine optimised for spool tends to fall flat on it's face up the rev range. By fiddling with inlet and exhaust cams you can dial the the problem out a bit but it seems to always result in a coompromise.

The other way to create more energy is to increase the kinetic energy within the gas flow. One way to do this is to increase the volume of exhaust gas coming out of the engine; this is where nitrous oxide comes into play. The normal air entering the engine is 20.9% oxygen, in comparison N2O is 33% oxygen. Also N2O is 50% denser than air, so every cubic foot of nitrous oxide injected into the engine contain 2.3 times more oxygen than a cubic foot of air would do. Put enough fuel in to use up that oxygen and you are able to increase engine power, with the added benefit that you are also substantially increasing the amount of exhaust gas trying to get out of the engine. The diameters of the runners within the manifold haven’t increased so all the extra gas has to flow faster to get out than it would without N2O, hence more kinetic energy to spin up the turbine.

Manifold design is also an important factor to consider; after all it’s the manifold’s responsibility to get the thermal and kinetic energy to the turbine as efficiently as possible. The exhaust gas enters the manifold in a series of pulses as each exhaust valve opens. On a log/branch type manifold where all the runners dump into a common plenum that then leads to the turbo it’s possible for these pulses of gas to collide with each other and end up cancelling each other out, this slows the gas and results in less kinetic getting to the turbine. This is why twin-entry and individual runner manifolds provide more power, they keep the exhaust gas pulses apart. On a 4-cylinder engine the twin-entry type manifold combines cylinders 1&4, and 2&3 into two runners that are kept separate right to the turbine wheel. The cylinders that are paired together don’t coincide in the firing sequence so there exhaust pulses are unlikely to encounter each other. The result is that the turbine wheel ‘sees’ 4 strong pulses of exhaust gas rather than a mixture of strong and muffled pulses. This results in a faster spool. Individual runners go one step further and isolate all 4 cylinders from one another till they get to the turbo. By using equal length runners the 4 pulses all take the same amount of time to get to the turbine, so they arrive as evenly spaced events. Hence why the equal-length individual-runner manifold is the desired design in a turbo car.

Anything that slows the exhaust gas down and causes it to lose kinetic energy on it’s way to the turbine needs to be eliminated, hence why porting and polishing exhaust manifolds can yield noticeable results both in terms of spool and ultimate power production.


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PostPosted: Mon Oct 03, 2011 10:59 am 
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Hi

Dan wrote:
Manifold design is also an important factor to consider; after all it’s the manifold’s responsibility to get the thermal and kinetic energy to the turbine as efficiently as possible. The exhaust gas enters the manifold in a series of pulses as each exhaust valve opens. On a log/branch type manifold where all the runners dump into a common plenum that then leads to the turbo it’s possible for these pulses of gas to collide with each other and end up cancelling each other out, this slows the gas and results in less kinetic getting to the turbine. This is why twin-entry and individual runner manifolds provide more power, they keep the exhaust gas pulses apart. On a 4-cylinder engine the twin-entry type manifold combines cylinders 1&4, and 2&3 into two runners that are kept separate right to the turbine wheel. The cylinders that are paired together don’t coincide in the firing sequence so there exhaust pulses are unlikely to encounter each other. The result is that the turbine wheel ‘sees’ 4 strong pulses of exhaust gas rather than a mixture of strong and muffled pulses. This results in a faster spool. Individual runners go one step further and isolate all 4 cylinders from one another till they get to the turbo. By using equal length runners the 4 pulses all take the same amount of time to get to the turbine, so they arrive as evenly spaced events. Hence why the equal-length individual-runner manifold is the desired design in a turbo car.

Anything that slows the exhaust gas down and causes it to lose kinetic energy on it’s way to the turbine needs to be eliminated, hence why porting and polishing exhaust manifolds can yield noticeable results both in terms of spool and ultimate power production.


this makes the OEM manifold bad becouse he isn't able to make a correct pulse timing
-> a corolla wrc manifold should can help

there is possible another way, i'am told that TTE used the water injection for a more responsive engine, but therefore you need a full controllable WI (correct water flow at every specific engine point), time, money and a dyno for R&D to get me maximum out


greetz

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PostPosted: Mon Oct 03, 2011 5:22 pm 
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Sunny wrote:
this makes the OEM manifold bad becouse he isn't able to make a correct pulse timing
-> a corolla wrc manifold should can help


Yeah, the stock manifold wasn't optimised for power delivery - it's a compromise between power and manufacturing cost!

Indeed a TTE/WRC manifold flows much better. Even the cheap eBay tubular manifolds are superior to the standard manifold from a flow/power point of view, people notice bhp and torque increases with them. But being welded from unsuitable grades of stainless steel and often having to hold the weight of an unsupported turbo results in their premature failure.


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PostPosted: Mon Oct 03, 2011 6:25 pm 
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So would it be worth me getting a tubular manifold? i can get all the welds done better and tronger plus make better brackets for it to take the weight.

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PostPosted: Mon Oct 03, 2011 6:46 pm 
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Hi,

i'am with Dan, but even you build a manifold by yourself stainless is stainless so the possability of cracks stay in place and it will crack not today not tomorrow but anytime

iirc you are using a FMIC, definitely not a cheap way but i would consider a corolla manifold

on my engine i will go that way with a cast adapter and a ceramic coating on both parts + a BW EFR turbo should well work
meanwhile i know just one guy with a EFR 6758 it spools ~1bar at ~3000rpm (no coating, single entry) on his car even he is able for 450-500HP

greetz

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PostPosted: Tue Oct 04, 2011 8:35 pm 
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Sunny wrote:
Hi,

i'am with Dan, but even you build a manifold by yourself stainless is stainless so the possability of cracks stay in place and it will crack not today not tomorrow but anytime


So use something other than stainless steel, plain normal steel has a lower thermal expansion ratio so is less likely to crack. On a few types of cars it's popular to fabricate manifolds from steel weldable-elbows (aka weldels or butt-weld elbows/fittings). They're cheap as well, each elbow costs £2-4.
ImageImage

I'm going to try this as a method for making an individual runner equal length manifold. Imagine this with the welds ground back and the whole thing ceramic coated:

Image
Image

Sunny wrote:
meanwhile i know just one guy with a EFR 6758 it spools ~1bar at ~3000rpm (no coating, single entry) on his car even he is able for 450-500HP

greetz


I really like the look of the smaller EFR6258 as a 420bhp turbo..... 8) Is that guy you know running it in a GT-Four?


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