Hilux 4x4 Forum

I'm looking at upgrading my exhaust. I've got 09 hilux at with unichip in tuned by ksd. They recommended that with 76mm exhaust I would be able to push a bit more power safety.

Is there any disadvantages to fitting 76mm? Who in cape town would you recommend? And should it be done from the downpipe? Cat removed?

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Muki, just be careful that you don't make that free flow too flowy. I made mine flow verrrrry well. Too well actually and now I get a intermittent (once every 3 months with ambient between 14-16 deg C) P1251 error and subsequent limp mode requiring a shutdown, wait 30sec and start to clear the error.

The stepper motor can't adjust fast enough to prevent a pressure spike in the intake manifold. This happens when you go from coasting/idling behind a truck and floor it it to go past. Not so nice when you go into limp mode then...

But since you mention that you have a chip. Its possible to have the boost threshold level moved or the P1251 error parameters adjusted.

I'm still stuck with a racechip while the unichip is lying in the drawer waiting to be fitted when the world turns a bit slower. I will do a post when the unichip gets fitted and resolves my problem.

So in short, it is possible to have the D4D flow too much. I must add I have a automatic and it seems to be a little more prone to get this P1251 error.

JohanW wrote:Muki, just be careful that you don't make that free flow too flowy. I made mine flow verrrrry well. Too well actually and now I get a intermittent (once every 3 months with ambient between 14-16 deg C) P1251 error and subsequent limp mode requiring a shutdown, wait 30sec and start to clear the error.

The stepper motor can't adjust fast enough to prevent a pressure spike in the intake manifold. This happens when you go from coasting/idling behind a truck and floor it it to go past. Not so nice when you go into limp mode then...

But since you mention that you have a chip. Its possible to have the boost threshold level moved or the P1251 error parameters adjusted.

I'm still stuck with a racechip while the unichip is lying in the drawer waiting to be fitted when the world turns a bit slower. I will do a post when the unichip gets fitted and resolves my problem.

So in short, it is possible to have the D4D flow too much. I must add I have a automatic and it seems to be a little more prone to get this P1251 error.

Thanks, I'll definitely keep this in mind. I'm thinking one. Or 2 boxes as I don't want it to be too noisy.

What type of power gains did you get? And who done your exhaust for you?

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muki wrote:

JohanW wrote:Muki, just be careful that you don't make that free flow too flowy. I made mine flow verrrrry well. Too well actually and now I get a intermittent (once every 3 months with ambient between 14-16 deg C) P1251 error and subsequent limp mode requiring a shutdown, wait 30sec and start to clear the error.

The stepper motor can't adjust fast enough to prevent a pressure spike in the intake manifold. This happens when you go from coasting/idling behind a truck and floor it it to go past. Not so nice when you go into limp mode then...

But since you mention that you have a chip. Its possible to have the boost threshold level moved or the P1251 error parameters adjusted.

I'm still stuck with a racechip while the unichip is lying in the drawer waiting to be fitted when the world turns a bit slower. I will do a post when the unichip gets fitted and resolves my problem.

So in short, it is possible to have the D4D flow too much. I must add I have a automatic and it seems to be a little more prone to get this P1251 error.

Thanks, I'll definitely keep this in mind. I'm thinking one. Or 2 boxes as I don't want it to be too noisy.

What type of power gains did you get? And who done your exhaust for you?

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Power gains... No idea. Turbo lag is gone though which makes quite a difference if you know how sluggish takeoff normally is with the AT. Need to get it on the dyno which will happen in the new year when I fit the dastek chip. Kept the original downpipe, since that is nice and big already. Then a single 67mm powerflow box and out the side in front of the right rear wheel. Not loud at all. Just a hearty grumble when the turbo vanes open up. 67mm pipe used from box onwards.

KSD did my 76mm exhaust. De Graaff bolt on kit. From turbo to the back.
Pulls like a freight train, also with the Unichip.

Go for it!!

Kaaskrul wrote:KSD did my 76mm exhaust. De Graaff bolt on kit. From turbo to the back.
Pulls like a freight train, also with the Unichip.

Go for it!!

Pierre is your D4d a Auto?

Kaaskrul wrote:KSD did my 76mm exhaust. De Graaff bolt on kit. From turbo to the back.
Pulls like a freight train, also with the Unichip.

Go for it!!

When did you have it done? Last time I spoke to ksd they sent me to noise boys.

Can I ask how much it was? Can PM me if you prefer?

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Kaaskrul wrote:KSD did my 76mm exhaust. De Graaff bolt on kit. From turbo to the back.
Pulls like a freight train, also with the Unichip.

Go for it!!

Hi kaaskrul what Toyota u got I also want to go the degraff 76mm route but don't have a chip my hilux is a 2007 3.0 d4d will it be a problem as mine has 260k on the clock and I don't want to put more strain on a older model with high kilometres. Did u notice more power and better fuel economy as I can't get better than 8.5 k per litre think my exhaust is blocked as my hilux is a bit sluggish I have a pedel booster in as well . I am on what's app if u want to contact me 0826952481 would like to see his you system looks if possible thanks Brent

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If I may ask, what was the cost of the degraaf system?

I fitted 76mm exhaust system from noise boys yesterday on vigo. Sounds lovely and pulls nicely. Will be going to ksd by end of the month.

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muki wrote: ↑Thu May 11, 2017 4:08 pm I fitted 76mm exhaust system from noise boys yesterday on vigo. Sounds lovely and pulls nicely. Will be going to ksd by end of the month.

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What did the exhaust system cost?

Omo wrote:

muki wrote: ↑Thu May 11, 2017 4:08 pm I fitted 76mm exhaust system from noise boys yesterday on vigo. Sounds lovely and pulls nicely. Will be going to ksd by end of the month.

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What did the exhaust system cost?

R3500

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Would fitting just a freeflow box have any influence?
That way there is still some restriction but with better flow.

There isnt really a consensus from everyone I spoke to. but from the various discussion I had the following seems to be most likely.

1. The catalytic converter will give a big restriction, so removal of this would be ideal.
2. Pipe diameter does not matter much on a turbo diesel, hence you can go as big as 76mm. NA petrol engines need their exhaust matched to the engine.
3. Mandrel bends are best.
4. The box does play a role, but seems to be less important than the catalytic converter or pipe diameter.
5. Major benefit of fitting bigger exhaust is reduction in EGT. And dont forget the lovely noise it makes :D

I may be wrong, so dont take my word on it, but this would be my opinion from the short amount of research I done.

muki wrote: ↑Wed May 17, 2017 1:06 pm There isnt really a consensus from everyone I spoke to. but from the various discussion I had the following seems to be most likely.

1. The catalytic converter will give a big restriction, so removal of this would be ideal.
2. Pipe diameter does not matter much on a turbo diesel, hence you can go as big as 76mm. NA petrol engines need their exhaust matched to the engine.
3. Mandrel bends are best.
4. The box does play a role, but seems to be less important than the catalytic converter or pipe diameter.
5. Major benefit of fitting bigger exhaust is reduction in EGT. And dont forget the lovely noise it makes :D

I may be wrong, so dont take my word on it, but this would be my opinion from the short amount of research I done.

Awesome Thanks. I am very familiar with petrol engines, setups etc. Diesel is new to me.

RiyadhFortuner wrote:

muki wrote: ↑Wed May 17, 2017 1:06 pm There isnt really a consensus from everyone I spoke to. but from the various discussion I had the following seems to be most likely.

1. The catalytic converter will give a big restriction, so removal of this would be ideal.
2. Pipe diameter does not matter much on a turbo diesel, hence you can go as big as 76mm. NA petrol engines need their exhaust matched to the engine.
3. Mandrel bends are best.
4. The box does play a role, but seems to be less important than the catalytic converter or pipe diameter.
5. Major benefit of fitting bigger exhaust is reduction in EGT. And dont forget the lovely noise it makes :D

I may be wrong, so dont take my word on it, but this would be my opinion from the short amount of research I done.

Awesome Thanks. I am very familiar with petrol engines, setups etc. Diesel is new to me.

Dyno results after remap [IMG]//uploads.tapatalk-cdn.com/201705 ... 03e701.jpg[/IMG]

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Nice 5.3kw increase