The Turbo I Should Get Is........

[GSTdude06]

Ok last weekend I installed my FMIC w/ short route piping. Monday I got my 650cc injectors in. My goal is 300whp and I no im fwd so ill spin but im getting a shep racing tranny and lsd soon. At the moment I have....

Intake
3" Exhaust
No Cat
255 fuel pump
Rewire
FPR
8.5mm spark plug wires
New spark plugs
1g TB
Geddy BOV
Ported 1g exhaust manifold
14b
Port O2 housing
Logger
SAFC


With a good tune will a EVOIII 16G bring me to my goal without running all the guts out of it?

I want to have some safty on the turbo.

Help is appreciated

Thanks,

 

[TheArtist]

Yes, Evo III 16g will be perfect for your goal. The evo III 16g is the best turbo I've ever come accross for the dsm. Get your hands on it now!! Artist.

 

[DGajre777]

Yes 300whp can be done with an Evo III.

 

[GSTdude06]

Thanks for the fast reply. What is the hp it can support? To the crank or the wheels either or.

Thanks,

 

[SinaiTSi]

SBR has had an Evo 3 16g dyno at over 400 hp.........I was told it was with a 2.4L stroker and on a fwd though. So, alot depends on setup, tuning, etc. Since you're fwd, you'll obviously see more whp too.

Also, I noticed that in your mods, you have a ported 1g exhaust manifold, why? I'm just curious as to why you didn't stick with your 2g mani. which is better.

 

[GSTdude06]

When I took my stock turbo set up off the bolts where rusted to the manifold and no matter what I did I couldnt break them off. I soaked them a million times still nothing I used a impact on it still nothing. And when I bought my 14b it came with the turbo manifold and o2 housing and 1g side mount.....

 

[SinaiTSi]

I knew there had to be a reason, it's no big deal though. It's not like the the 1g mani. is a ticking bomb, like some people would like to believe. If it does ever crack on you, or you just want to replace it, I have this mani. and I like it. Besides, you really can't go wrong with the price.

http://www.turbochargers.com/store/product_info.php?cPath=38_27&products_id=121

 

[GSTdude06]

Ya thats a good price but im going with a tubular manifold with the EVOIII 16g, faster spool... I got another ? tho... what does fuel cut feel like? A pop and car jerks?

 

[GSntncT]

It's possible. Gonna have to be a damn near perfect tune though. But I have a question for you. If you do reach 300 whp, will that actually be it for you? I ask this because there are too many of us here that say they'll call it quits once the reach a certain level, however when they reach it, they continue building.

Either way, best of luck with the 16G. I had a 16G, and didn't particularly care for it. I think it was mainly do to me having the turbo clipped.

 

[GSTdude06]

Well here in my area if I get to 300whp Ill beat most people in my area and I dont really want to have to upgrade my internals but if I do im going to buy another engine cause mine is getting high miles.

Any answers for the fuel cut? Pops and jerks at high rpms......

 

[jpbrazill]

Something you also want to keep in mind is the motor work. Yes, with your mods and a 16g, you can reach 300whp. You will pushing somewhere between 17 and 20psi out of the turbo. Im assuming you want the 300whp on pump gas right?

Keep in mind that cams, head work, and bottom end parts are going to change your numbers drastically.

J.P.

 

[GSTdude06]

I will have my cam and cam shafts later one when I get a SMIM.

Fuel Cut answers?!

 

[DGajre777]

Fuel Cut answers?!

What is "fuel cut"?

When the ECU detects a condition that the factory didn't intend the engine to experience, it will try to save the engine using something commonly known as "fuel cut". All of the injectors are shut off as well as all the spark plugs, effectively shutting down the engine. When the condition has passed, the ECU will go back to running spark and fuel as normal. You might experience this as a violent bucking sensation.

or

Fuel cut is cessation of fuel delivery and spark generation by the ECU. It is a pre-programmed response designed to save the turbocharger from utter destruction in the event of a catastrophic wastegate malfunction.

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What conditions will cause fuel cut?

There are three conditions under which the DSM ECU will chop fuel.

Engine speed higher than 7500 RPM. This is overrev protection. If your engine rotates faster than the valve springs can pull the valves back up into the head, the pistons could smack into them, causing major damage. Note that simply chopping fuel will not stop the overrev condition if you misshift and the transmission rotates the engine past the revlimit. (The author did this to his friend's M3.)
Engine air flow greater than a certain amount. If the airflow into the becomes too great, the phenomenon by which the MAF counts the air entering the engine starts to break down, missing counts. The factory ECU sets a very conservative limit here. It doesn't need to be as conservative as it is to prevent missing counts. After we removed this limit, we were only able to hit the MAF counting breakdown problem on a first generation DSM with a 20G set to 19 psi on a 3" exhaust.
Engine under high vacuum for more than a couple seconds. This is not a matter of engine safety, but of smog control. Some of the worst smog can occur during engine deceleration. If you are coasting down a steep hill using the engine to help slow you, the ECU will turn off all fuel to the engine to both aid in engine braking and smog production.

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What does fuel cut feel like?

Like you hit a brick wall, if it happens when you have the throttle to the floor. Typically, the ECU thinks too much air is entering the engine, the engine shuts completely off, the air amount decreases to under the limit, and the engine goes back on again. This can be quite jerky.

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How do I prevent fuel cut?
I have [injectors/fuel pump/fuel rail] installed, but I still get fuel cut! Is there a fix?

This question comes up a lot, mostly because people misunderstand what fuel cut is for, and why it occurs at all. For the answer to this, read this chapter of the ECU Primer.

The simple answer is that because fuel cut is pre-programmed into the ECU, there is no method of disabling it. There are no modifications that can do so, aside from an ECU upgrade that eliminates fuel cut. Upgraded fuel pumps, injectors, and fuel pressure regulators do nothing to avoid or eliminate fuel cut. NOTHING.

That being said, there are some methods (some cheap, some not) of postponing fuel cut. All the methods work on one principle: fooling the ECU into thinking there is less air entering the engine than, in fact, there is. This can be done by adding unmetered air, or by changing the sensor inputs used by the ECU to determine air mass. Of course, these methods usually mean the engines run leaner than stock. Again, read this section of the ECU primer for details.

Methods include:

removing the lower honeycomb from the MAS. See the FAQ Locator (look in the "Intake" section) and Jim McKenna's MAS modification page for more information.
'Gutting' (cutting out) the lower section of the MAS. This modification was first marketed by HKS, improved upon by Roger Hanson, Eric Typpo and Jim McKenna, and recently re-popularized by Al Blaha. This involves cutting out the entire lower section of the MAS - delaying fuel cut, but making the engine run leaner - and altering the intake air temperature sensor to compensate. Mike Jackson also does this - read his information here.
plumbing in a secondary air intake after the MAS. Use extreme caution!
the fuel cut defenser (FCD) by HKS
the dime-store fuel cut defenser (DSFCD) for 1G or 2G. Use appropriate caution.
fuel management computers, like a VPC or PMS. See the Glossary for details.
An ECU upgrade from Technomotive is the only way to really eliminate fuel cut.

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ECU Primer, Chapter 7: DSMs and fuel cut

Turbochargers are positive feedback devices - the faster they spin, the more air they push into the engine. The more air they push into the engine, the more exhaust gases are produced. The more exhaust gases that are produced, and the faster the turbo spins. The faster they spin....

See the problem? The faster they go, the faster they go! Eventually something would have to break. To prevent this situation from occuring at all, turbos have a device on them called a wastegate that limits the turbo speeds to manageable levels. This is a pressure-activated valve that opens at a preset pressure and vents additional intake pressure either to the atmosphere or back into the exhaust stream.

Modern turbo design notwithstanding, it is still very possible for the wastegate on the turbo to malfunction, leading to exactly the ever-faster turbo behavior described above. Recognizing this, the designers of the DSM ECU built a fail-safe limiting mechanism into the DSM ECU modules. And it goes like this:

Should the ECU ever see an intake air mass greater than a certain preset level, it will stop fuel delivery and spark to the engine cylinders. This 'critical mass' depends on air volume, temperature and pressure, as measured by the MAS sensors. The act of the ECU cutting off fuel delivery to the engine is known as the infamous 'fuel cut'.

Why'd they do this?? Well, should the wastegate ever malfunction in such a way as to allow the turbo to spin out of control, the ECU will stop firing the cylinders to save the turbo from exploding. This is not the only method the ECU has to limit the turbo operation, but it is the last and most desperate. The mass air limit at which the ECU will fuel cut was based off of the maximum amount of fuel that the stock fuel pump and injectors could deliver to the engine cylinders.

Unfortunately, those owners who purposefully modify their engines to provide greater power are deliberately forcing more air through their engines in order to produce more power. Recognizing the limitations of the stock fuel delivery system, serious modders usually upgrade the fuel pump and/or injectors in order to provide enough fuel capacity for the hopped-up engine.

However, the fuel cut limit, based on the stock fuel system, is pre-programmed into the ECU and cannot be changed. There is no method by which the ECU can be made aware of the improvements made to the fuel system, so it will blithely cease fuel delivery once the mass air intake reaches a predetermined level regardless of how much fuel capacity is really available. This characteristic of the DSM ECUs, while understandable, has been a source of nearly endless frustration for power-hungry owners.

There are solutions to this problem. Aside from reprogramming the ECU (which is sometimes possible) to eliminate the fuel cut, all of these solutions utilize the same basic principle - fool the ECU into believing there is less air entering the engine than, in fact, there is. This is often accomplished by altering one or more of the input signals sent to the ECU by the various air measurement sensors present in the MAS.

For example, a volume of air at higher temperature contains a smaller mass of air than an equivalent volume at lower temperature. The ECU determines the intake air temperature from a sensor in the MAS. Electrically altering this signal can make the ECU read a higher air temperature than actually exists. Based on this erroneous temperature, the ECU will calculate the mass air intake as being less than the actual amount.

Even expensive fuel control systems utilize this technique to keep the ECU from activating fuel cut. These systems, however, often intercept more than one ECU signal, and can provide their own monitoring equipment to allow the operator to properly observe the condition of the operating engine. This allows the owner to 'fine-tune' the car to achieve the desired characteristics while keeping the engine safe from harm.

Obviously, doing this type of modification is a relatively dangerous process. By changing the ECU inputs, the operator runs the risk of altering both open and closed-loop ECU operation to the point where the engine does not receive enough fuel. As always, it is up to the operator to monitor the engine operation to ensure that a damaging situation does not occur.
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Sources: www.vfaq.com, ECU Primer, www.tmo.com