Ok then its a different matter actually... Lets just say higher gains are easily possible. I thought you meant the any "standard" tubular manifold more or less.

 

I was meaning both standard inlet and standard exhaust manifold, compared to your modified items....

 

Brilliant, very interesting read

 

Just a quick 2 cents. Turbo charging is not the only system that eats power to make power. A pro dragster uses over 500HP to to turn their superchargers at full song.

 

Well now you are just being crude... No, i dont want to say anything in public actually about that matter. For two reasons, one, it will be bragging according to me, two, i have no actual proof for stating these numbers. Lets just say that my results will speak later on... Hopefully, and probably, its a completely different matter than 500 rpm, i can say as much. During the summer i will be running my car with my own intake and a heavily modified standard Sierra RWD manifold. We may notice...

 

I must say that as interesting as the comments are on this post, unfortunetly the vast majority are flawed.

Whilst in theory all that hexxon mentions is the aim, in reality such benefits are barely realised. The polishing and preparation of manifolds such as the item shown earlier on this post will in reality make no difference. (i.e. it is so significantly small it can be classed as normal error)

The critical parameters in any engine are actually of a much larger scale. By this I mean there are certain factors that are important and fundamental to engine power and other factors that allthough nice in principal make virtually no difference.

For example there is far more benefit in optimising the valve seat design and area than any kind of polished porting makes. The idea of polishing things is near comical in terms of generating any benefit!!

To summarise I would say that whilst theory is a great starting point, in reality it is only R&D followed by testing that actually gives the best results. It is also often somewhat of an eye opener to find the things you thought in theory work, do in fact make no or even a negative difference! With that in mind I would recommend Hexxon to be a little more open minded than post lots of theoretical ideas that are in fact incorrect and short sighted!!

For example inlet manifold heat isolation from the head is irrelevant. The air velocity at high boost/rpm is so great that the available surface area in the inlet tract contributes virtually no heat to the inlet charge air.

Hope everyone has fun on this thread, thats it from me for now!

 

a PROPER devil's advocate .

 

Patrik,
Once you have modified your inlet and exhaust manifold, I could back to back test it for you on an engine dyno...

 

Not really, i dont think anyone would argue with that to be honest Mike. But i do personally think Hexxon is very open minded, its simply that he hasnt been drawn into any discussion or dabate and therefore has so far just given us his personal opinions and outlined ideals, which i for one am happy to give my time to reading as they are very interesting. Wether or not anyone agrees has not been touched upon.

Keep it up IMO

 

so you can effectively spin the turbo up earlier by having more energy in the exhaust gas. more energy can be from a higher velocity, or a higher temperature, right?

so do we map the engine to give a weaker than we might normally mixture at the point where we can expect boost to be coming in to make a higher EGT and get the turbo spooled up quicker? or is this counterproductive as by leaning off the mixture we generate less power?

 

mike its karls dannys quad cooler set up
:blabla

counbt them
lol
danny did martoons in a 3 set up cuz martoon wanted to be diffent and used escort cozzy coolers
gave a slighly smaller overall size as the 4 set up

 

It was Martin's I was thinking of . Is yours done with 2wd cores then?

 

Thanks for the critique!

Mentioning surface quality as something comical is however strange. Polishing anything might be taking it to the extreme, though the importance of radiused trumpets actually being evenly radiused not looking like something carved out of a piece of old wood is actually improving air flow by considerable amounts. Seen that.

Polishing in ports is well comical. Agreed. Theres more drawbacks on that than positives. The valve seats, together with the area surrounding every valve, is the single most flow affecting area in all of the engine. There has been no discussion in this thread regarding this. But id love to partake in one such discussion. Start away Karl!

Theory combined with practice is a difficult one? Well, no theoretical system works when applied sadly in practice. Thats all i have to say about that. You can make cute drawings on things, set up the theoretical system for it. But when you have applied it in practice, it didnt work, why? Because no effort was put in place to realize your theories with enough preciseness. Mathematics and physics are based on theories that often involves exact values to be attained from what do. Another problem with theories is the fact that people take things to easily, assuming to much, when putting these systems together. Simulating air flow in an engine could, first of all, not by any means be simulated using statical methods. No way. The dynamics involved in an engine is what makes the engine deliver. Period. So what does all of this have to do with anything? Well. If im about to carry out calculations on an intake, i DEMAND it to be exactly the way i set it up in the model. Please, check again, any differences on the surface of any of my trumpets? Any difference in the ports? Balance. Polishing an item is the best way to identify strange surfacing. I often polish ports to detect these things when porting, later on making the texture rough when im pleased.

Theres no such things as irrelevance when adding together the positive effects. The heat transmitted into relative fast air of the plenum might not lead to huge increases in charge temperature. But its there. So why not make things better. Scrappy solutions is not something i want to come up with...

Again, thanks for the critique, albeit all of it negative.

-Patrik.

 

Id love to! It will be done in sweden to, but the more the merrier.

 

Your welcome Hexxon.

I had visions of everyone removing their inlet and exhaust manifolds to spend countless days and hours polishing the tracts only to refit and find it makes no noticable difference!!!!

Yes once EVERY design parameter has been exhausted you can look to blue printing the design (i.e. polishing production flaws out) but it's such a TINY gain for the required hours, it simply is'nt worth considering for anything other than a professional racing team working to strict rules!

I don't mean to poo poo your comments, but I feel you're quoting theory without having experianced the reality. You for one should know that time is far better spent on other areas than simply producing a mirror like finish inside the inlet manifold.

 

Sure, thats a well known fact, that even works in practice

Wouldnt recommend running leaner than what the engine can take, at any point!

 

Well those visions must have been of the nightmare kind eh? Does sound like me though... I find no remorse in spending days after days making something as good as i possibly can get it... Strange one me.

I dont think about it in that way actually Karl. The engine which i am building right now is made for a car, which i regardless of what, will keep for the rest of my life. A day in that perspective... Besides that, im a perfectionist and enjoy doing things the best i can.

It would seem as if i have no practice to back up my theories huh? I understand this. Let me say something about my relation to cars and engines without sounding like a hot shot. Im 22 years old. Since the day i was born to the day i was ten, my father was a engine builder. He built engines for rally cars as well as other racing engines. One of his merits was performing the milling in some of Opels Gr-B car, the Manta 400, cylinder head. Never having this as his primary source of income though, always as his greatest joy and hobby. Me im raised with this. Ported my first pieces when i was about ten. Been having access to flow-benches since then, got tired of them as well, realizing what anyone should. They dont give much information actually.

Actually, i did nowhere say that a mirror-like finish is something that is always better than anything else? Thats false accusations... The inside of my inlet manifold is not mirror-like if you look at it again.

Well, cheers Karl for your constructive criticism!

-Patrik.

 

Patrik,
Don't worry about Karl, he likes to poo-poo anybody that doesn't think the same as him .

 

Mike.. this is now for you..

 

No worries at all Mike

I find it interesting with different aspects of it all. Some rely more heavily on what they practically think is correct, others on theoretical matters.
Few combines theory and practice though. Because its as distant as alpha and omega actually. Theres few good engine builders in the world capable of this...

The funny thing though is that everybody still claims that theory and practice isnt combinable, and still they enjoy F1 and Cosworth engines? Why?

 

the gathered crowd is hushed as mike has just proclaimed that there could be more than one god

 

ROFLOL @ Nick

 

Haha, LOL! No... Dont go that far...

 

sorry, don't mean to disrupt the thread.

let's get back to the discussion. any input to my small question stu?

 

Patrick answered it for you actually Nick

And i concur that yes, we often lean out the boost spool area of the map to marginally within the safety limit to encourage rapid spooling of the turbocharger and then slightly and brefly overfuel once at peak boost to restabilise the EGT's if the application warrants it.

 

thank you Patrik and Stu for your helpful responses. that's something else i've learnt today so i'm happy.

 

Yes, I ALWAYS do that as well Stu...

 

I never doubted it for a minute Porkie

Nick, as always your welcome

 

Hello again,

Sorry to have to disagree but I do not concur with Stu and Hexxon.

There is actually no gain and only a degredation in performance by leaning during the spool zone of the boost map. The reason for this is because any benefit in turbo response realised from increased exhaust gas temperature does in fact take longer to occur than the boost spool. By this i mean that the EGT does not increase immediately with leaning AFR. In reality it actually takes a few seconds for any change in EGT to occur by which time spool up has occured.

The negative side to lean spool is reduced engine torque (which in essence means lower cylinder pressures) and this means slower boost spool.

In practice we use ignition timing to actively assist spool time as this has a direct and fast acting impact on EGT's where as AFR has a slow response (relatively)effect on EGT.

 

Surely Karl you can see that you would have to know what figure we were leaning from and to in order to make that boldly sweeping statement and given that no such mixtures have been quoted in this thread i find that it a rather spurious statement to make. Some OEM manufacturers are using as rich as lambda 0.72 in teh spooling area and maintaining this to peak boost and leaning this to 0.90 can give very noticeable throttle response and spool improvements indeed. As for losing torque by leaning, given teh two examples ive just quoted, do you stand by that?

Early Mitsubishi and Subaru's are 2 prime examples here of modern sports cars with this excessive spool AF/ratios.

I also dissagree with what you have said there about it taking a few seconds for the EGT to change as it simply doesnt. Ive had the distinct joy of using new oem electronic EGT monitoring systems such as those fitted to late Audi RS6's and corresponding similar high HP models with onboard EGT mixture adaptation and i can assure you the change is near instantaneous and can be easily viewed with Good OBD2 monitoring equiptment... as you would expect from a changing chemical burn, its fast. The delay your likely reading and remembering is actually from the piss poor EGT probes commonly used to monitor EGT by teh aftermarket which will in fact have let an engine meltdown before they bothered recording the heat increase at teh head unit..lol. Also, most EGT monitoring systems are measuring the surrounding hardware temperature when teh gas has infact been travelling over it at subsonic speeds and slowly heating it for some measurable time. The turbine housing is reacting to the gas temp directly and the fact its expanding when leaving the confines of the hot chamber and coming into a relatively cool manifold, giving rise to larger expansion rates than before, thus giving more torque to the turbine wheel, which is exactly the effect we were after for initial spool improvements.

Spark advance / retard strategies go without saying but that wasnt the topic was it?

 

Karl loves to PooPoo

Then again its the only way we get any info from him normally, thank god for Stu n Pat most times

 

I got lost after page 1, I have no idea on who's right or who's wrong.

But I'm getting there.

I have found one fundamental flaw in all of your quotes..................















When I copy & paste to word, you should see the amount of grammar mistakes


Oh THIS HAS TO BE THE BEST POST I'VE EVER READ.....PERIOD

 

WOW. what can i say? i love it when a topic like this comes up and we get different opinions from the pro's

i can see both points. when i've got my programmable ecu i will try each way for myself and see which is best for my engine.

 

Its differences of opinion that make the world progress folks

Otherwise we would still be living on a flat planet eh?

Karl,
One day we will bolt that GT40 to that std YB mate... hows New years eve sound to you?

 

Yeah Stu it would indeed be a VERY interesting project. "How much power can be extracted from a TOTALLY STANDARD YB with just a wire rung block, BIG turbo and BIG injectors!!

 

I REALLY want to see this, as in lots of countries this is the common thing to do, and they get good results.

Go for it

 

Me say 650 BHP!!!!

 

Put a post together then guys.. all those interested must donate a part so it doesnt cost me and karl fortunes to do it....

STD YB.. Big Turbo, Level 8... Karl can build it, we will both map it, and off we go, just for teh hell of it

In fact, if it costs us NOTHING... we can donate the finished lump to a PF rafflewinner

 

You git, youve just had me go back and edit the reply i gave to karl at the end of page 7.. i was rushing to get to teh postie, thats my excuse

 

on a totally std engine with just a big turbo and big injectors....you'd make no more than 440bhp due to the flow restrictions......run as much boost as you like....but you can only go so far on a 8-1 *safe* ignition map and that on my turbo for example is 1.6bar...after that the more boost dont = faster...BUT i dont run a very safe map a run a damn right dangerous one ...so more boost = stupid power..BUT then my car can consume ALL the air produced.