things to upgrade for high performance

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Originally Posted by c.h.i.e.f

I should have also used the words "cross sectional area" and not surface area haha
Personally I am going to use what you and randy have used but I just wanted to question it just incase.
I am going to steer clear from the thinner stuff as I will not trust it whilst under extreme temps,vibration and an expensive turbo hanging from it I would hate it to crack :mad: plus the thicker wall will help retain heat which from what I can gather is beneficial in our application. From the bends I have played with they have a wall thickness of around 3mm is this similar to yours John ?
I also do not ubderstand the 20,000Rpm statement ? Assuming when you say reducing the size of the tubes will increase velocity this would be the same as a smaller A/R Exhaust housing I would imagine..

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I don't have my pipe catalogues/table with me, but the wall thickness of the lighter 40 NB, butt weld fittings will not cause a problem for you as they are still plenty thick enough.

I don't have my un-finished manifold here, so can't check the wall thickness of the fittings - they are in the order of 3 mm.

BTW, although pipe is sized on the bore, (tube on outside diameter) the outside diameter remains the same for different wall thicknesses, and inside diameter changes (thus the use of Nominal bore. Butt weld fittings are for pressure purposes, thus the need for the different wall thicknesses. The schedule number is based upon a pressure rating, so thickness of, say sch 40 will vary with NB - if bore increases the wall thickness has to increase for same pressure.

Increasing velocity in a manifold branch will not compensate for A/R in the turbine housing as the velocity in the housing is determine by the nozzle cross section area. Some turbo manufaturers don't state A/R, but give the area in cm^2

The reason that the pulse converter has an area reduction to increase velocity is to avoid flow reversal (and loss of pulse pressure) down the other branch.

Auh ok well looks like I'll be trying to source some 40NB bends and the pulse converter to go with it then...I'm hoping this will help gain a noticeable gain in spool up time cross fingers haha

When your manifold cracks you'll be spewing, not many have lots of luck with made manifolds

40NB pipe is 48.3mm OD, in SCH40 (aka medium wall or STD) it has a wall thickness of 3.68mm.

so 44.62mm ID?
rovercare when you say crack do you mean the material itself? of the welding that fails? i dont know if tig,mig or stick welding would be best ? then again it might work out more benefitial just to run with my standard turbo manifold....

Would Ceramic coating exh manifolds inside and out and same to front piece of exhaust pipe help with performance?

Yes would help a bit from thermal point of view I would say

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Originally Posted by land864

Would Ceramic coating exh manifolds inside and out and same to front piece of exhaust pipe help with performance?

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Not as much as fitting a turbo and intercooler ;)

Steve

Oh I didn't realize you were referring to a NA motor having ceramic coating because as Steve said turbo and inter cooler are the pick

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Originally Posted by Bush65

Oh dear :eek:
The pulse converters you are referring to are used on and were developed by manufactures of large marine diesels as used in ships.

Your comment about needing to spin at about 20 000 rpm is way off and very missleading - how do you substantiate the 20 000 rpm comment?

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quite simply, but first you have to understand the problems that the ship builders had to overcome.
Big displacement low revving and with a tail pipe about 20 klms long ( usually vertically)
There problem was the gas cooling down becoming denser and not wanting to move, so they used the pulse or sonic pulse to help as well and making the cross section smaller.
in your application i believe that you are looking at this method to overcome or reduce the flow back or the lack of savaging ( for want of a better word) that the turbo produces.
in short the shorter the exorst pipe the higher the revs need to be before realising the benefits. 20000rpm for a 4bd, I was exaggerating, I thought it was funny, you didn’t.

But what’s really funny is, I have posted before about pulses and there benefits and was POO POOed but the so called Isuzu knowitalls. Now it seems that others wish to pursue this topic and those who did the POO POING before now seem to be authorities.

Sounds like an aussie pollies flip flop