MadMac

as there have been a few posts on the forum about this so far, was thinking.

Turbos are good because they dont rely on anything to drive them except the gasses comeing out of the engine. So apart from causing a bit back pressure, they wont restrict the engine in any way.

But they need time to spool up to get max power, they get hot and usually a small problem can cause huge damage, plus you have the added problem of ATC being high from the hot turbo.

Then you have supercharges, which use the engine to drive them. So you lose some BHP just because you have to drive it. But you gain a lot more back. They work continuously providing boost at idle, dont get hot, so wont lose BHP through high ATC temperatures so wont require and intercooler. They dont require cooling and a constant supply of oil and are more reliable. And they sound the tits on full chat.

But they dont spin as fast as turbos do at top end so while produce more power low down, dont produce as much higher up.

Ok thats simple enough.... but what one do you go for? I can't decide if I want to use a turbo on my 2.0 Zetec or go something a bit differnet, get a supercharger.

turbo chatter or charger scream?
High top end power or lower but even power?



What do you guys think?

mattbibs

for me the first attraction of an RS was going out in an S2 and for it to properly pin you back when it came on boost!

turbos for me every time! there are other benefits but you cant beat the grin factor when you boosting!

Stavros

THEY DO GET HOT AND REQUIRE INTERCOOLING WITH ANY REAL BOOST
THEY DO REQUIRE LUBRICATION
THEY DONT LAST ANY MORE MILES
ANY S/C PROBLEM IS JUST AS DAMAGING AS A TURBO ONE
MODERN TURBOCHARGERS ARE HUGELY MORE EFFICENT THAN S/C's
And so on and so forth..

Thats all pissed on your bonfire a fair bit hasnt it

I think you need to know a lot more about things before you start on about them mate

I love superchargers but we in 2004, modern turbo technology makes superchargers almost redundant, if you USE IT.

PS- Charger scream is mainly from old innecficient roots style chargers, more modern chargers arnt anywhere near as noisy really, no more so than turbos, and big boost turbos make a hell of a scream too.

Hofajoab

if i had the money i would get a supercharger... but i love the basic principles of a turbo, it makes sense.

i'm only guessing here but i would think that if you were tracking the car a lot then a supercharger would be better as it would have a 'smoother' power curve making the car more stable? But if you wanted a car that would put a grin on your face from time to time on the backroad or whatever then a turbo running high boost would tend to do that more than the supercharger..

i don't think in general terms running moderate BHP it would make too much of a difference which one you went for, although i would love a supercharger if i could afford it.. although saying that i love the basic principles of a turbo using what would be 'wasted' exhaust gasses to produce more power - it makes perfect sense!

MadMac

Thing is I like power when I want it, dont wanna wait for a turbo to spool up, get bost and then fly off. I want foot down and off.

Well ya get that from either a hoooooooooge yank V8 or a supercharged engine.... am I wrong in thinking that?

Stavros

If you was on a backroad (i presume you mean a twisty one) then technicly a cheap supercharger conversion will be more fun than a cheap turbo conversion, as the s/c will have no lag, the turbo *might*, depending what sort of spec we talking about.

One thing people dont seem to get is on MOST superchargers you only get full boost at full revs, you dont boot it and you at full boost even at 1000rpm and it stays like that, it rises with the revs as its only 1 gear and works off engine revs, so with modern turbo once you in the midrange and beyond youl find the turbo is boosting MORE even if the supercharger is set to run the same peak boost pressure

You can technicly idve thought run a wastegate to bleed off pressure tho, possibly, so its mega high geared from the start, but bleeds off air once maximum has been reached, but i can only think of 1 ive seen like that i think

And dont forget youl get the same compressor surge with a supercharger, so it no point having big boost low down as the engine cant deal with it, same as with a turbo.

Anyone know the technical reasons why you cant run any overlap on S/C engines (so i hear?)? That must be a shitter too...

Stavros

Unless your car is horrendously badly specced you wont ever have to wait for it to spool up, if you do, your in the wrong gear! If your in the boost threshold then even a modern 500bhp+ turbo on a 2litre has no lag to speak of.

For example, lets take Rod's car...

2.2litre 4cyl 16v YB, 7.2:1compression, using a fecking huge GT35R turbo.



200lb/ft, std cossie performance at under 3000rpm! You want lowdown power? lol...
200bhp by under 4000rpm too! Lag?

4250rpm... midrange, where even the most pussy drivers rev to...
375bhp and the torque about 470lb/ft! Why do you need a big V8 again?

Oh dear, look further...
The power steadily rises and peaks at 6800rpm at 614bhp and stays not far from the 600bhp mark upto and beyond 7500rpm,

Oh deary me again, torque keeps rising even more and peaks at 508lb/ft at 6000rpm, stays above 450lb/ft till 7250rpm, and even at 7500and beyond its still 400lb/ft...

That pisses over the performance a 2.2litre supercharged engine can give, low down AND high up.

And thats with a huge GT35R which is good for 700bhp! If you only want the power most supercharged 2litres would give you, ie about 250bhp for a goodun, then you could fit a GT28RS, have about 330bhp and NO LAG, far more low down power than a supercharger as well as a good 80bhp more!

Like i said, i love em, but not half as useful as they used to be...

They not bad as low boost things to fit to n/a cars, but if you want proper power it gets more expensive than a turbo and shows no real gains with todays modern turbos.

Twincharged engines do sound 100% sex tho, and the idea of getting a sierra, bashing in a lightly modded 302ci ford V8, and run 2x cossie T3s and a rootes charger sounds a good cheap idea, for the noise alone...

MadMac

God steve you really are a smart arse git arn't ya

mattbibs

wow - havent seen that graph before!

MadMac

Steve before you start ripping the piss out of my knowlege of these things please bare in mind I have only a level 3 betec in it auto engineering. Basic principals and old tech only. And I did that course 5 years ago. So I dont know about "latest technology" and I can't spend my time looking this stuff up which is why I asked and didn't want smart arsed and quite frankly irritating responces.

Would you pleeeeaaaasssee think about what your typing and how people are going to read it before you start going into one. Because what you have written reads as a total putdown.

Instead of big capital letter going NO NO NO try typing yes this is true, however blah blah blah, come on steve your an alright bloke but just think about the person thats going to read you comments.

You say a turbo charger pisses over a supercharger, WHY? put up another graph of a similar spec engine with a supercharger prove your point, I didn't want a 1k by 1k analysis of Rob car because I dont want to build a 600bhp cossie. I couldn't use a car like that.

So if they are so restrictive and so un powerful, why do dragcars use them? Why do busses and trucks use supercharged diesel engines if they dont respond any better than a turbo at low revs? Why are they still big in the us, africa and australia?

Stavros

Oh dear...

Firstly, tho you was online and read my reply immediatley (and even posted a reply), so why wait till i was gone to bed before you replied in this way? So everyone could read your slating without a reply? (Esp as ive not been online on the weekend for about a month now so itd have a good few days of it) Thats pretty low i think, but anyhow, lets explain...

Basicly mate, the way YOU wrote your things about superchargers (and about how bad turbos are), you was writing it like it was fact, when in fact it was all wrong, and nothing more i hate about the internet is one person writes totaly false stuff as fact, and then a 100 people reads it as fact, and belives it, and tells a load more people, and so on, so i put the story straight, not trying to put you or anyone down, your a sound bloke, wasnt trying to be nasty...
Dont get me wrong, i dont know everythnig, far far faaaaaaaaaaaar from it, and would never think so, but i know what you were saying wasnt right, and only wrote in the way i did as the way you wrote what you did was making out it was fact, when it was infact fiction, lol

I wasnt taking the piss out of YOU for a start, dont take it to heart.
I have a level1 fuck all in jack shit mate. I got no qualifications in owt to do with cars, you got a lot more than me. Im no mechanic, but nor is a lot of tuners, lol, i just have a good mind for modifying force inducted cars for more power for some reason.
I not got loads of time to read about stuff, no offence but i prob got a lot more going on in my life than yourself, its just i learn these things. You always on here reading the same stuff as me, suprised you not learnt stuff too.

Oh matey
This comment was blatantly to try n call my bluff as you didnt expect me to have a similar graph. I didnt have a grpah last nite (tho ive already explained why a turbo is better than a s/c if you READ my posts properly ) but just as a total fluke i have now found (before i even read this thread today ) i found a comparison graph

Sorry about the quality, but its a screengrab...

This engine is supercharged AND turbo, just over 2litres again, twincam 16v. Huge turbo and a supercharger too. In a 10sec Manta.
Cant really compare torque as easy as its NM, but even comparing that cars low down power with a supercharger, to Rods with a huge turbo, a turbo nobody in their right mind would choose if they wanted supercharger performance, theres no much difference, lol.
And that car uses a huge turbo to give it the high RPM power as the s/c obv couldnt give it that to that extent.
If you want supercharger type performance, on a relativley low spec engine, youd run a GT28RS, which is half the size of a GT35, so really does have no lag at all, which is what i said all along.
Im sure i could find a GT28RS powergraph somewhere if you like...

If you READ my post i explained all that
I used rods car to show you even somthing with a huge laggy turbo isnt laggy these days. And also said if you used a smaller turbo (GT28RS) on a lowish spec engine, the same engine youd fit a s/c too, if the s/c would be about 250bhp, the GT28RS would prob be 300+ and far far greater low down power.

Drag racers use them as they always have, and more and more are changing over to turbos. Supercharger is good, ive said that, but nowhere near as good as a turbo. Maybe the rules/times they work to means they have no need for turbos, im not sure on the rules.

Busses and trucks with supercharged diesels? Where? The 50s? Seriously mate, VERY few in modern times. Go look at 100s of modern busses and lorrys, oh looky, a fucking great turbo. Cant miss them on most HGV cabs as they visible from the outside so can see them while waiting next to them at the lights etc...
Actually, i dont know if the trains round by you are diesel or electric, but they diesel round here, and if you at the station and one of the smaller 2-3 car passenger things turns up, look down near the wheels where they exhausts come from... Ooh looky, a bloody great turbo again, lol.

Big in the US with braindead hicks, but i dunno if youve looked mate, but most big power yank V8 engines built for the past quite a few years are turbo, not s/c...
Its not big in Oz, they well into turbos. No bigger than here, or anywhere else.
Big in africa? Damn, africa, the pinnacle of modern technology

Like i said ALL ALONG, i love superchargers, i been telling my mate with an M3EVO that if he wants more power id get a big boost supercharger conversion rahter than a turbo as i think it suits the car better, the way it is. But its just the stuff you came out with (written like it was FACTO) was just not true, and if everyone reads untrue stuff that they think is fact, they belive it, and next thing you know everyone belives summat thats not tue.

Like "wastegate chatter"

hexxon

Thats a fairly nice engine characteristic. The torque at 3000 rpm aint that impressive as you may sound it to be though.

The fact is that the superchargers of today, are FAR mor efficient than the old rumpy rooters. Do a quick search on lysholm?

There is a clear advantage on high output engines to employ compound charging.

EDIT: Saw your post on hilmerssons manta, he uses an old type rooter, Eaton M62, to be precise. Not very efficient stuff as it comes to volumeric efficiency.

Stavros

Yup, the 2nd powergraph i posted shows that compound charging (ie supercharger AND turbo) is a good plan if specced correctly

My main point was tho that MadMacs facts on turbos were far far from true.

Muska

interesting reading

wimwerf

but you need an intercooler with a supercharger if it boosting enough.

Smit

iTrader: (5)

Ste - that 2nd graph is making my eyes go funny

top reading though.

Stavros

wim- i said that in my first post, basicly ignore macs comments, they not quite right (ie they wrong )

smit- its shit innit but if u want a proper view, dowload this vid of the engine on the dyno, the sheet is shown at the end in better quality- http://www.hilmersson-racing.com/bil..._bromsning.mpg

the films of the actual car running is even better tho

hexxon

I will help you guys out with the swedish parts

This is a much better view of the sheet:
http://www.hilmersson-racing.com/bil.../bromsning.pdf

Stavros

Nice one mate! And from that PDF, ive made this, so everyone can see...

RODS COSSIE


Mad Super+Turbo Charged Manta


What is the exact spec of the engine? Im sure its on that website but i cant read sweedish too well, lol. Il try find my way around it in a min...

Your english is perfect by the way, its crazy, we cant speak any foriegn languages really but everyone can speak english, we lazy...

Stavros

Dang I can see it now "FOR SALE, 1 mad single throttle GTR custom inlet. Sale due to bolting on a huge supercharger in its place

hexxon

Perhaps a interpretation of the two sheets?

As can be seen the compound charged car attains a much higher power output from the low rev-range. Hence the powerful torque. The power generated by the compound engine is superior, comparing to rods, up to a certain limit where i presume the supercharger gets way inefficient. When the turbo kicks in for both of them its a big difference, rods engine apparently having a much better engine set up for the turbo in use(no shit!? GT40(Diesel aggregate) versus WAY more efficient GT35R), due to the actual climbing of power through the entire register.

The spec of the engine is as follows, copied from the site:
Volvo B230 with navy crankshaft
SPM H-profile connecting rods
Venolia pistons
16 Valve Volvo head with standard valves, port grinded with own ideas
Self made mechanical valve adjustment
Camshafts grinded by SPM
Double valve springs
Garret GT-40 turbo
Eaton M62 compressor with an own system for control of air between the turbo and the compressor
Exhaust manifold manufactured in stainless steel
Wastegate with 50mm valve
Self made intake manifold with separate 46mm throttle and full radius funnels
Autronic engine management system and CDI ignition
Mercury F1 ignition coils
Self made Intercooler and watercooler

http://www.hilmersson-racing.com/start.asp?show=j

Any more specs wanted? Its stated out much more in dept in swedish on the site...

Itsmeagain: Thanks for the critics on my english All of my studies here in sweden at university is performed using english material actually, all my essays are in english and so on... Besides that im part linguist part computer scientist

hexxon

Performing a compound charging on the GTR? If thats the case, PM me.