turbos wich is better on a ka24de

[mean green s14]

my preference is the t04b-r i got with my nsport kit, its good to 450 hp and with a heat sheild really spools up qiuck for a larger turbo.

what do you guys think of your expieriences with the t04b and how does it compare to the other turbos usually used in ka24det set ups?

[HIGHLIFE]

got the same t04b-r and love it. i was thinking about getting a heat shield for mine, but i've heard it shortens the life span of the turbo. BTW what kind of heat shield are you using on yours. don't mean to hijack your thread, just wondering.

J

[trpower7]

A heat shield has nothign to do with how fast it spools up. Read and search, there are a million threads about different turbos people have used.

[Checkered-Member]

A heat shield has nothign to do with how fast it spools up. Read and search, there are a million threads about different turbos people have used.

oh ho....refer to the sticky on the top of the page in this forum

[Checkered-Member]

Back to the turbos. It all depends on how much power you want, where you want it, and how soon you want it.

T25 way too smallT28 too smallT3 it’s small but if you want some quick low end powerT3/T4 most popular one, since its so common you can get a really good deal.T4 this is good if you want plenty top end power >T4 you will need some major engine work, if you are running 16+ psi

I swear to god, some one is going to jump is and say “you are wrong you can use a T25-8”You *can* if you don’t want any power past 5,000rpm

[C-Kwik]

>T4 you will need some major engine work, if you are running 16+ psi

You'll likely need this major engine work with a smaller turbo than a larger turbo. Larger turbos typically run at higher efficiencies and are less of a restriction in the exhaust. Given the same level of boost, a smaller turbo will have a lower threshold of detonation due to heat and backpressure. Except perhaps at low boost pressures. But even at 10-15 psi, the larger turbos will probably be at higher efficiencies already.

[WDRacing]

A heat shield has nothign to do with how fast it spools up. Read and search, there are a million threads about different turbos people have used.

Actually by keeping the hot exhaust gasses inside the manifold or turbine section, the will continue to expand and there velocity will remain higher then if they were allowed to cool. In turn increasing the spool of said turbine. By how much, I won't say, but it can help. And the "Search" post is no longer allowed on my forum. Please don't say anything at all if you don't have somthing to offer. Thanks alot.

WD

[andrave]

You'll likely need this major engine work with a smaller turbo than a larger turbo. Larger turbos typically run at higher efficiencies and are less of a restriction in the exhaust. Given the same level of boost, a smaller turbo will have a lower threshold of detonation due to heat and backpressure. Except perhaps at low boost pressures. But even at 10-15 psi, the larger turbos will probably be at higher efficiencies already.

could you explain that a little further? I've never heard this claim made before.

[rco8786]

could you explain that a little further? I've never heard this claim made before.

Maximum Boost by Corey Bell explains it well. Basically a bigger turbo is going to produce less heat and operate at a higher efficiency. Less heat = less detonation.

[andrave]

right, but as long as you didn't detonate why would using a smaller turbo require you to build your engine? If you are making the same power without detonation I don't think the size of the turbo would make a difference.

[trpower7]

The point is the addition of a heat shield will not make an appreciable difference. The theory is correct, but a simple shield won't really yield a result. However, ceramic coating, heat wrapping, or any other kind of full enclosure will produce some results. A heat shield merely directs heat in a different direction, it does not seal it into the said turbo. I'm glad I'll get to see the same answers a million times over so we can all feel important that we know something, why don't we take away the search function all-together if we won't make people use it? Or we could cater to those that are too lazy to do some good research and use their heads.........your choice..........

[hannibal]

I think building your motor (head/valve work) can help improve the efficiency of the smaller turbo. Getting the air into and out of the cylinder more efficiently means your turbo wouldn't have to work as hard.I'm sure building the head would help efficiency on a larger turbo too, but would have a greater effect on a small turbo (T3) running relatively high boost (10-15 psi).

AS far as needing headwork to run a big turbo, could a KA flow enough air to support a turbo that big without building the head??

my non-professional opinionJay

[mean green s14]

he trpower! why dont you tr to smile once in a while, it takes less muscles you know! and to everyone else, thanks for your POSITIVE feedback!!!

[trpower7]

hah, not trying to be a jackass, just want clear, concise, useful, true information, and as little useless repetition as possible. And by the way "It takes 10 muscles to frown and only 6 to smile, but it only takes 3 to reach up and smack that mother-****** in the jaw"

[mean green s14]

puase and count backwards from 10!

dont like the thread dont read!

start your own thread and name it "dont have anything better to do than be rude to people asking questions"!!!!!!!!!!!!!!!!!!

[WDRacing]

Hey TR, I completely understand your point, this thread is actually not the same as the usual what turbo is better thread.

Its my job to answer the simple questions with a link to the info or by simply deleting the thread and emailing the member with a "how to get better responses" note. You'd be surprised if you knew how many threads I lock or delete in here.

I somtimes feel like being a complete **** and bashing a member when they ask extremely dumb questions, but why bother. Its simply to easy to help.

We all start out as newbs...Well ok, I have always been a genious...lol.

WD

[MikeMurphy]

right, but as long as you didn't detonate why would using a smaller turbo require you to build your engine? If you are making the same power without detonation I don't think the size of the turbo would make a difference.

its not uncommon for exhaust manifold pressures to be over 2 times the intake manifold pressures under load, with a turbo that is too small. The more pressure you have the more residual air your left with after combustion obviously. That can lead to detonation.

I cant imagine building up something for a small turbo. It would make far more sense to address the problem rather than the symptoms.

[:: orion ::]

1)I think building your motor (head/valve work) can help improve the efficiency of the smaller turbo. Getting the air into and out of the cylinder more efficiently means your turbo wouldn't have to work as hard.

2) I'm sure building the head would help efficiency on a larger turbo too, but would have a greater effect on a small turbo (T3) running relatively high boost (10-15 psi).

1) Improve the efficiency of the motor, yes. Improve the turbo's efficiency, NO. The turbo efficiency is ploted on the compressor map - For a given pressure ratio, it will be XX% efficient. Can't change that unless you modify the compressor...So the air it's blowing will still be nice and hot, helping to increase your chance of detonation.

2) Backwards. Making a smaller turbo force air through passages that move the air more slowly will hurt the efficeny of the system...but a big turbo, that's good and efficient up top, will benefit. A small one that isn't as efficient near redline will suffer b/c of the extra volume and slower air velocity of the bigger ports.

Later - Brian

[C-Kwik]

right, but as long as you didn't detonate why would using a smaller turbo require you to build your engine? If you are making the same power without detonation I don't think the size of the turbo would make a difference.

But to make the same power with a smaller turbo, you would need to boost more. While turbos do use some of the energy wasted out of the exhaust, it's not entirely free. The turbo IS a restriction in the exhaust stream. This means the motor has to pump harder to force gas out of the cylinders. Smaller turbos are more restrictive for at least two reasons. The major two are that the turbine itself is smaller and can flow less air, and since the turbine blade tip is closer to the center of rotation, the air has less leverage over the turbine. The second is that a smaller turbine is typically combined with a small compressor. Smaller compressors have to spin faster to reach the same boost level. To spin the compressor faster, you must spin the turbine faster. To spin the turbine faster, more air must be forced through the turbine. To force more air through the turbine, a higher exhaust manifold pressure must be reached. Consequently, this is seen as backpressure by the motor and the motor has to pump harder to move that air and the next charge of air will by diluted by a higher concentration of exhaust gas that couldn't be pushed out. With all the higher stresses on the motor, the higher boost required and the hotter exhaust gasses created by the excess backpressure, you would be more prone to detonate with a smaller turbo than a larger one given the same boost. Or even the same power.

[C-Kwik]

As far as the heat shield is concerned, it will have very little effect. Heat shields are designed to keep heat from radiating out into the engine compartment. But it's not designed to keep heat in the turbine. It has a very small side effect of keeping a small amount of heat in the turbine, but it will still let plenty out. Keep in mind the turbine is hardley a factor in allowing heat to escape. The manifold will be much more critical in that aspect as tube length can be a factor and 4 tubes have a much higher surface area to volume ratio than the turbine housing. If keeping heat in the turbine is an important factor to you, consider a jet hot, ceramic, or other heat insulating coating on the turbine...

[WDRacing]

just arguing a point thats all C-Kwik. I know a heat shiled isn't gonna yield any actual gains. I did get good results with thermo tech wrap though, header, turbine, downpipe etc...

[hannibal]

Thanks for the correction Brian. Good explanation, C-Kwik.

[andrave]

yeah this thread turned useful. good info, brought up some things I haven't thought about.

[mean green s14]

well think of it this way,why do people put a cold air intake on there car? to get colder "less" dense air,thus more air into there engine and combust the cold air more efficiently,so as for a turbo, hot air would have more desity and thus help to spool the turbo faster and more efficiently! in tern resulting on more hp sooner in the rpm band and more boost quicker!

[Nathan]

Ya got that backward man, cold air is denser.

[C-Kwik]

well think of it this way,why do people put a cold air intake on there car? to get colder "less" dense air,thus more air into there engine and combust the cold air more efficiently,so as for a turbo, hot air would have more desity and thus help to spool the turbo faster and more efficiently! in tern resulting on more hp sooner in the rpm band and more boost quicker!

Hot air has more energy. The turbine is designed to convert pressure and heat into mechanical energy. If the motor coming out the exhaust port were the same as ambient, the turbine would have to be powered strictly by pressure. The heat in the turbine will have very little effect on the temperature in the intake.