Anyone done any gas flowing ?

[Jonathan]

Reading Dermots page I was gonna give that a go sometime as I wanted something to do on the car I can take into the garage - gas flowing and polishing sounds ideal.

Has anyone done it at all or am I gonna fly blind on this one.

What about seperating the back side of the plenum from the throttle bodies - I was told not to do this before, is it a problem ? Any major precautions to take ?

Other than that I guess you just radius and smooth / steam line the flow - seems easy enough but always wary of jobs like that...

[Newts]

Hi Jon

(More than) A few years ago I built an Escort with a 1600 cross-flow that could out-accelerate a 3 Ltr Capri. Part of that was gas flowing or porting and polishing the head in a very unscientific way.

Essentially with a flexi- drive and some small grinding wheels I smoothed out all the rough edges of the inlet and exhaust ports in the head and matched the manifolds to the head to eliminate any steps or irregularities, the general principle being to ensure that the gases flowed much better without any undue restrictions or turbulence.

You can buy quite a few books on the subject, but a lot of it is common sense (possible naive statement there ??)

[gtt dave j esprit]

for the gains your going to see at midi core power its not worth the effort unless your borad. on an n/a engine sure. but with forced induction i dont see the point. just turn your boost up

[greekmix]

I agree with the note above its will not be worth it if you are not prepered to do going though some more mods to see the effect.

I have done this on mine and dyno tested before and after with no real big change.

The change came on some extra mods which I apply and the best of all was the exhaust system.

My notes can be found here lotusesprit.com.au in case you need more info.

On the other hand avery little clean up you can do will help if you add them all together you may see thesome results.

If I was you I will start with the fist two mod stages on my pages before pulling anything else apart...

HINT: Be careful playing with the turbocharger!!!!

[matk]

Crikey David, you're a bit negative aren't you?

If you're going to make sweeping statements it would be useful to hear a little of the science behind your thoughts?

Chapmans principles in designing the car were to extract as much out of things as possible with the least engineering. Just turning the boost up could have all sort of negative effects on engine integrity and longevity. What's so wrong with gas flowing so that the gas path in the engine flows easier? Of course its easier to turn up the boost, we all know that! That's not what Jon was asking about!

Edit - Tony posted at the same time. At least he's providing a little info on his thoughts.

[andydclements]

I'd go with Dave as well.

The point of porting an NA is that it's just the pressure differential that forces the air in (there's no pull, it's a push by the atmoshere), with a forced induction, you can achieve the same by simply increasing the push. The only thing yuo may want to achieve is a smoother path, so the turbo has to do less work to move the amount of air, thus allowing freeer flowing exhaust gasses past the turbo.

[rogerch]

Whilst not disagreeing with the "Turn up the boost lobby" There are other factors, when I first pulled the induction side down, I found po had fitted 40mm "O" ring carrier/spacers I replaced them with the proper 45's and just made sure everything matched, result a very noticeable performance gain, whilst not exactly gas flowing, just getting it right can offer gains without increasing boost pressure.

I did that later.

[mike_sekinger]

I think that it

[Jonathan]

That was the idea Mike, to keep the boost down. Thanks for all that have replied as well.

The reason why I dont wanna up the boost is the temperature - you can rob quite a few horses from the chargecooler by doing that and raising it's temperature.

I do prefer the brains over brawn approach though, but I take into account the comments made - I like messing about with the car so for me it's not a case of money / time - it's a hobby.

What I was looking to do was the same as Dermot had done on his inlet which is really opening the plemun, not the head. My main q was whether it is safe to remove the back end of the plenum from the throttle bodys.

Tony - I will have a look at your site asap

cheers

[Winter]

See the topic I raised on 28 Feb 2009 in the V8 section entitled Gas Flowing that subsequently was moved to General motoring/Lotus/Esprit chat.

[Jonathan]

Didnt see that and I did a search as well !

[jonwat]

http://www.lotusespritforum.com/forums/ind...mp;#entry221812