More inlet cam duration on a turbocharged engine

[turbotoaster]

Evoluzione said:

I'm not sure you are learning, you are picking at other peoples knowledge base and even then you aren't really reading it properly and just bolting on one random part after another.
Go back to my very first post and read it carefully, then apply it to what you have done by simply swapping one turbo for another.
You have the same resources available to you as anyone else does (including me), that includes books, compressor maps and to some degree, technical forums. I suggest sitting down and reading them. Tedious I know, but you'll educate yourself, save time, money and stand a good chance of wheeling something out of the shed that works properly.

Once you've been pointed in the general direction you will have to do some actual work yourself!

What is working in your favour is (hopefully) you've built a strong bottom end, you have 9:1 CR and a long stroke. These work well with a longer duration cam - just make sure you have enough piston/valve clearance if you do any cam swaps....

Edited by Evoluzione on Tuesday 2nd February 13:42

Your right, I wasnt learning, i was just trying to pick bits of info out of it to use.

you mention in your first big post the turbo isnt big enough overall for the power that im now looking for, so all the additional information ive added isnt really going to change that fact.

I have been looking online at the moment to see the best way to connect into the manifold to measure EBP as you need something that you can easily block off after, might go and see pirtek local and see what they would recommend, im guessing something like a oil braided line with screw on fitting on the manifold itself. I will do some more research to see what pressure ratio is to high vs whats ideal, that might teach me how big i need to go on the turbine side to give the best overall power band.

Stevieturbo, since i have a ported head in pieces, the £180 for double valve springs makes sense to put them in now and will cover for the future if i want to go bigger cams

Thanks for both of your help, as you both say, until i know the EBP im purely guessing what the issue could be.

[stevieturbo]

turbotoaster said:

Your right, I wasnt learning, i was just trying to pick bits of info out of it to use.

you mention in your first big post the turbo isnt big enough overall for the power that im now looking for, so all the additional information ive added isnt really going to change that fact.

I have been looking online at the moment to see the best way to connect into the manifold to measure EBP as you need something that you can easily block off after, might go and see pirtek local and see what they would recommend, im guessing something like a oil braided line with screw on fitting on the manifold itself. I will do some more research to see what pressure ratio is to high vs whats ideal, that might teach me how big i need to go on the turbine side to give the best overall power band.

Stevieturbo, since i have a ported head in pieces, the £180 for double valve springs makes sense to put them in now and will cover for the future if i want to go bigger cams

Thanks for both of your help, as you both say, until i know the EBP im purely guessing what the issue could be.

Just weld a female brake fitting onto the collector, that way you can just route some copper brake pipe to a pressure gauge. Then after just stick a bleed nipple into the threaded hole to seal it up.

Cheap and easy.

[Evoluzione]

turbotoaster said:

Evoluzione said:

I'm not sure you are learning, you are picking at other peoples knowledge base and even then you aren't really reading it properly and just bolting on one random part after another.
Go back to my very first post and read it carefully, then apply it to what you have done by simply swapping one turbo for another.
You have the same resources available to you as anyone else does (including me), that includes books, compressor maps and to some degree, technical forums. I suggest sitting down and reading them. Tedious I know, but you'll educate yourself, save time, money and stand a good chance of wheeling something out of the shed that works properly.

Once you've been pointed in the general direction you will have to do some actual work yourself!

What is working in your favour is (hopefully) you've built a strong bottom end, you have 9:1 CR and a long stroke. These work well with a longer duration cam - just make sure you have enough piston/valve clearance if you do any cam swaps....

Edited by Evoluzione on Tuesday 2nd February 13:42

Your right, I wasnt learning, i was just trying to pick bits of info out of it to use.

you mention in your first big post the turbo isnt big enough overall for the power that im now looking for, so all the additional information ive added isnt really going to change that fact.

I have been looking online at the moment to see the best way to connect into the manifold to measure EBP as you need something that you can easily block off after, might go and see pirtek local and see what they would recommend, im guessing something like a oil braided line with screw on fitting on the manifold itself. I will do some more research to see what pressure ratio is to high vs whats ideal, that might teach me how big i need to go on the turbine side to give the best overall power band.

Stevieturbo, since i have a ported head in pieces, the £180 for double valve springs makes sense to put them in now and will cover for the future if i want to go bigger cams

Thanks for both of your help, as you both say, until i know the EBP im purely guessing what the issue could be.

Yes the amount of air you quoted that your turbo will supply is more likely to give a 360 bhp and that is pushing it a bit.
Can you get me some more dimensions? What does your intake manifold look like?

[turbotoaster]

Evoluzione said:

Yes the amount of air you quoted that your turbo will supply is more likely to give a 360 bhp and that is pushing it a bit.
Can you get me some more dimensions? What does your intake manifold look like?

Dont any more about the turbo in terms of dimensions than what I stated, what extra info do you need, the guy who built it for me told me hes had the turbo make 400bhp at 30psi on cosworth with a 0.63 turbine housing, so i was expecting with the 0.48 to maz circa 370bhp, but hold nice power to 7000rpm, saying that it could be cam timing that needs work.

here is a couple pictures of my current intake manifold, its now got a 56mm throttle body but had a 52mm one when it was last running.

The upper plenum is a turbotechnics cast version that is larger than the factory one, no trumpets or anything fancy inside

[Evoluzione]

turbotoaster said:

Dont any more about the turbo in terms of dimensions than what I stated, what extra info do you need, the guy who built it for me told me hes had the turbo make 400bhp at 30psi on cosworth with a 0.63 turbine housing, so i was expecting with the 0.48 to maz circa 370bhp, but hold nice power to 7000rpm, saying that it could be cam timing that needs work.

here is a couple pictures of my current intake manifold, its now got a 56mm throttle body but had a 52mm one when it was last running.

The upper plenum is a turbotechnics cast version that is larger than the factory one, no trumpets or anything fancy inside

It's the maths which points to 40lbs giving you 360bhp (on a 2ltr at 1.5 bar).
I like the way they've made everything in pieces, handy to be able to unbolt it all, also good how they've made the port entrances (and ex port exits) round which make life a lot easier for making parts than when they go oval.
Can you get me port length while you have the head off? From valve seat to port entrance, also intake manifold runner length and exhaust port length.
Also exhaust runner length from head flange to start of collector.
You can get these measurements by taking a piece of string or easily bendable wire and taking the short side of the port or runner, adding it to the measurement of the long side and dividing by two.
If you could get:
Rod length
Piston pin offset
Intake runner internal dia at start and at finish
Ex manifold internal diameter
It would be great, also:

Min cross sectional area (Min CSA) of port would be of use, but maybe a bit difficult dependent on what tools you have, if it's round a pair of internal calipers will get it, although I generally take a mould to get it exact. This is the tightest part of each port (per valve) and if you get a figure of about 400 - 450 mm squared I don't think you'll be far off.
Full cam specs including timing angles and valve clearance.

It would be interesting to run a Sim with those figures, maybe someone more knowledgeable with the head could help out

[nevcontractor]

Hi Lee,

I've had a skim read of this thread and though I know little/nothing about the K series I have a couple of observations:

1. Your exhaust manifold looks efficient, though you are unioning cyl 1+2 and 3+4 so there will be some mild pulse contention (rather than scavenging). Even so, your manifold is far better than a log design. This will help reduce pre-turbine EBP. This in turn will allow your turbo to swallow the air faster, which in turn means you can run more overlap on the valves.

2. I would recommend forking out for a bigger turbo TBH. It will give you several benefits, more flow at higher RPM, more efficent (less heat in the charge to cause problems), less strained (will last longer). As you know I use a GTX3071 on mine and have had no problems with it, for circa 425 BHP a GTX2867 will be a good choice.

3. Deffo put stronger valve springs in, it is a no-brainer, allows you to rev without worry of valve float.

As for cam profiles, I'd recommend ringing up Piper themselves. I did this about 6 years ago and talked to a couple of people, 1 of whom was quite knowledgable and helpful. I have quite a bit of overlap on mine (cant remember offhand) and 276 degree of open inlet side. I think (guesswork) that this has knackered my low end torque below about 3500 RPM (not helped by the mid sized turbo), but as you know at the top end my engine just keeps pulling like mad over 8000 RPM if I let it.

Another thing to consider is simply ringing up a genuine engine building expert of this engine and offering £100 for some advice/recommendations. There must be some people out there who have tried something very simlar and be able to reduce the guesswork you have to make. £100 spent like this could save thousands later on with mistakes/oversights IMO.

Good luck and keep spannering

Nev.

Edited by nevcontractor on Thursday 18th February 08:41

Edited by nevcontractor on Thursday 18th February 08:44