How do you emprove if.....

Discussion of technical issues and ideas (engine, chassis)

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Gary57
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Post by Gary57 »

The cam.....but does it really make a big diff on a turbo motor
I beg to differ, I just fitted one and it made a moer of a difference to the torque and I bet with the correct fueling (which it doesnt have right now) it will make a good difference at the top end rpm.

What you are trying to compare is like the Toyota 4AGE and CA18DET, just because they both have 16 valves doesnt make them the same.

But yes by lowering the CR and boost the car will make less power than it would a higher CR and more boost but still might make more power than std. If the parts that were changed were restricting the motors "flow" then at a lower boost lower CR it can still make more power than std. I know for a fact that the manifold is a HUGE restriction and the intake cam makes a wonderful difference.

You guys should go look for a CA18DE cam before you get it dyno tuned, a cheap mod aswell.
Hennie Marais
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Post by Hennie Marais »

Stock is a AR49 for the turbine housing, I've got 2 at home if someone wants one, hehehe. But ye, it'll be better.
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Draco
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Post by Draco »

Gary57 wrote:
The cam.....but does it really make a big diff on a turbo motor
I beg to differ, I just fitted one and it made a moer of a difference to the torque and I bet with the correct fueling (which it doesnt have right now) it will make a good difference at the top end rpm.

What you are trying to compare is like the Toyota 4AGE and CA18DET, just because they both have 16 valves doesnt make them the same.

But yes by lowering the CR and boost the car will make less power than it would a higher CR and more boost but still might make more power than std. If the parts that were changed were restricting the motors "flow" then at a lower boost lower CR it can still make more power than std. I know for a fact that the manifold is a HUGE restriction and the intake cam makes a wonderful difference.

You guys should go look for a CA18DE cam before you get it dyno tuned, a cheap mod aswell.
Did you fit both in and out or just out?
Hennie Marais
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Post by Hennie Marais »

Cams do make a difference but makes a better improvement when used with a larger turbo. problems can occure when you use to long duration cams with a small turbo as the backpressure on small turbo is very high, so "backflow" and contamination ocure with valve overlap. another problem is running longer duration cams move the powerband higher up the rev range and if you run a small turbo that's not able to supply the flow needed at that rpm then is sort of a waste. For street applications short duration cams like 254deg and higher lift (but calculated according to the valve size and portflow) will give nice results.
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Gary57
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Post by Gary57 »

I just fitted the inlet cam, the exhausts cams are the same. The CA18DE cam has 1mm more lift and 8 degrees more duration. I cant tell you the exact power difference because the car is going on a different dyno and has a bigger FMIC and exhaust manifold since the last tune, but I can deffinately feel a difference since I fitted the cam.
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Post by Hennie Marais »

gary, what manifold are you refering to, the exhaust manifold.
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Gary57
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Post by Gary57 »

Yes I changed the exhaust manifold but my above posts are refering to the inlet cam, std is 240degree 7mm lift, CA18DE cam is 248degree and 8mm lift.
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Draco
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Post by Draco »

So would it be adviseble for me to fit the inlet cam, I have a stock manifold and a T28 turbo?
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Gary57
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Post by Gary57 »

It will make more power for sure, the mid range torque is where the best improvements are so far but it still needs to be tuned.
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Post by Hennie Marais »

Stock manifold is not that bad actually, it's quite compact but if you remove it and look how the runners are grouped and split then you'll see it quite ok, not a poo Log style manifold but more in the direction of a compact unequal length manifold.
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Draco
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Post by Draco »

So the point is will my engin be relieble with the inlet cam, would there be a long term fall in reliebility?
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Gary57
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Post by Gary57 »

Well when I fitted the manifold (just a manifold change nothing else) the car went much better. I would say the mid range torque is about the same so is the lag but the top end power was where the biggest changes were. After 4500rpm I could deffinately feel more power.
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Gary57
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Post by Gary57 »

I cant see why the reliablity would change much. The wear on the motor will increase but that is because you are getting more cylinder pressure so therefroe more wear on the motor.
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Post by Hennie Marais »

Lol, that's the price you have to pay for power But I would worry if I were you, you're not going to half the life of you engine, it's still down to how you drive it.

The thing I notice with manifolds is the engine runs smoother, it doesn't always make more power , reason being the manifold is not the biggest restriction there, it's still the turbo, 95%+ of the backpressure is created by the turbo's turbine and turbine housing.
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Draco
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Post by Draco »

Well back to squere 1....it comes down to this, it doesn't help I get 10 cubic feet of cold air in but I am only able to get 5 cubic feet out....

As for the driving style....I'll have to seriosly start to convert to granny driving, I am punishing the Ca a bit....not as bad as many others but she is still hurting....
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