Throttle Bodies

[GoLfMan]

I've got to say Josh, if you reckon it's that easy to make 200hp from a NA 16V, everyone would be doing it incl. you.

It's much harder than you think..

no $hit its hard, and who says i wont do it, i may be a bit 'green' now but we all start somewhere, you were at this stage once too.

i think you misread my statement, of course its hard but its easily achievable as in you can easily achieve those figures with the right mods, its not like the engine isnt capable of it, just like V8's can easily achieve 800hp are we getting the picture yet???
As i said look at Preens engine, the amount of work into it and its going to be putting out circa 200hp, a good NA engine takes much more skill to build than a cheap turbo set up, wheres the sense of achievement in wacking on a hair dryer and winding up the boost?

Valvers engine that has been built specifically for big power turbo output takes skill, as do big power turbo 6's and 8's.

look at the first M3! 2.3L 4cyl quad throttle bodies, well designed engine and some crazy power, in race trim Jim Richards one was putting out 250kws!

its ok, have a crack mate i dont explain myself well sometimes
hopefully this time my statements will not be misconstrued.

this is not to be taken as an attack on anyone either, as this is a discussion and im just clearing up my point of view!!!

[Jarred]

lif you want ITB's for the sounds and "cool" factor, which is a good enough reason (if you've got the cash) you may as well get bike carbs an 8V!

really. bike carbs even with a custom manifold, will be a hell of alot cheaper than ITB's + ECU + tuning. Also about half as much as (brand new) twin DCOE's.

Ultimately twin DCOE's aren't the most effective/effiecient way of making power, but shure, they sound good!

IMO (and correct me if my figures are wrong, Tim) but and 2.0L 8V with bike carbs (quad 40mm, sim to twin 40mm DCOE) with a decent cam (around the 276 region) a bit of head work, (read: more flow) and a few other bits and pieces, exhaust etc. and a proper tuning, and you could be looking at 130kw @ flywheel.

140HP in a 900(or less) kg car, for street purposes (mainly) perfect. you don't need more than that.

The money you save over buying a 16V and ITB, ECU etc, you can spend on actually getting better parts for an 8V (pistons, rods, machine work etc) (that's where the extra 20 or so kw come in)

Anyways, that's just my opinion. My next petrol engine will be pretty similar, except k-jet, "stage 1" headwork, lightened flywheel, 276 cam, balanced bottom and prolly a 1.8. I'm hoping for 100HP. That'll be enough for me

[GoLfMan]

I'm hoping for 100HP. That'll be enough for me

the stock 2L put out 100hp and the 1.8 GTi engines put out 100hp why not get a 2L or a GTi engine

[Jarred]

EDIT: I'm getting confused with my HP and KW.
I want about 100kw (fly), which is pretty moderate estimate. could get a bit more.

[Oneofthegreats]

IMO (and correct me if my figures are wrong, Tim) but and 2.0L 8V with bike carbs (quad 40mm, sim to twin 40mm DCOE) with a decent cam (around the 276 region) a bit of head work, (read: more flow) and a few other bits and pieces, exhaust etc. and a proper tuning, and you could be looking at 130kw @ flywheel.

140HP in a 900(or less) kg car, for street purposes (mainly) perfect. you don't need more than that.

My next petrol engine will be pretty similar, except k-jet, "stage 1" headwork, lightened flywheel, 276 cam, balanced bottom and prolly a 1.8. I'm hoping for 100HP. That'll be enough for me

I reckon to make 130 engine kw's, you'd need a 2L with at least 11+:1 CR, very good head work, you may even need a worked over cross flow ABA head to achieve the flow number's required, twin 45's & a big cam. Something over 288. 4-1 race header's with around 1 3/4"primary's & a full 2.25+" system.
That should see you to 180hp, but it won't play nice on the street.

I spoke with a bloke in the state's & he runs a Audi 2L with high compresion, solid lifter head, 306° cam in a car that weigh's 1600lbs (800kg's full weight) & runs 14.0's with 1.8 60fts!

Also take into account that a 3dr mk1 is roughly 850kg's dry. Then put fuel in it & yourself & see how light it is. It's not the 110hp in a 800kg car anymore.
When I weighed my 5dr beater with half a tank of fuel & me in it it was 1000kg's dead even, so 800kg's full weight is some pretty impressive number's.

Not all GTI engine's produce 100+hp either. Depend's on the engine code, as there aren't that many that make the full 112hp, nor have the compression.

With the mod's made to my old beater engine & the MPH it ran in the GTI full weight it's making roughly 105whp. A ET/HP calculator reckon's 143hp! But I don't think so. I'm thinking maybe 125hp.
Not bad with basic mod's & part's, but also not very impressive IMO.
I'll take you for a spin when I get it going & I can garantee you'll still want heaps more.
Once the auto is fitted I may fit a turbo later in the year.

Josh, I forgot to add I was talking about Valver's NA ABF.

I'm more of a street/race engine person, use the car as much as possible & not once a month.
Don't get me wrong, I love High HP NA low capacity engine's but then I don't because they aren't ideal street engine's & in most case are normally pig's to drive with massive cam's & idle's at 1300+rpm , that's why FI is a better option.
I'd have a mild turbo'd 8V over a berg racer engine anyday.

I understand that some think it's easy with a turbo, but it's not that easy. You still need to find the right part's, the right combination, the right turbo. It's even more of a balancing act. A few degree's out on the timing & you've got some rod's & piston's that are nothing more than paper weight's.

It's just as involving, but when someone else has done it, it does make it easy to copy.

[GoLfMan]

i agree a highly strung NA around the street wouldnt be fun to drive in heavy traffic, thats why V8's are so much better to tune for power, minimal money on mods and you get massive gains and its still easy to live with!!

[Valver.]

Valvers engine that has been built specifically for big power turbo output

Just for the record, the ABF block in the white car is pretty much standard. It just has fresh parts, ARP bolts and a decompression plate.

TBH, I've built it to see how much boost it'll take before blowing up. It's actually RPMs that kill a 16v anyway; they seem to take a lot of boost for a long time if they're kept around a 7k rev limit

This is one of the other reasons it costs so much to build a nice ITB'd engine: the cams you need to actually use all that extra intake capacity demand so many revs, and you can't get much more than 7.5k out of a stock bottom end, and a bit over 8k revs from hydraulic lifters.

You also need to rev high enough to actually get a decent power band. If you didn't rev, you'd want a 7spd 'box!

There are huge improvements to made outside of the engine anyway. Putting a 3.94:1 final drive in a 16v 020 (and most 02As) feels like you've got another 30hp and your flywheel has shed half its weight. You can't really do this in a big boost engine as the torque will light up all the gears - you have to keep the longer ratios so it comes on a bit more lazily (unless have AWD of course). Being able to build a gearbox with taller 1st and 2nd, and then tighter stacked 3, 4, 5, 6 would be the best of both worlds, but that would be $15,000.

As Preen says earlier, getting near 200hp is great fun a Mk1 anyway I've only turbo'd mine out of curiousity - if the truth be known, it'll be a slower car in a lot of areas due to the lower compression, gearing, and the lag!

[Valver.]

P.S. A lot of the US and UK cars that apparently knock on 200hp with an $800 head job and KR cams need to remember that the early 16v power-up from Oettinger etc (with warm cams, great heads, and very nice exhausts) were only rated at around 175-180hp! The 190hp versions had 276 cams. I'd be more inclined to believe an engine dyno worth a few hundred grand than some bloke in a shed apparently getting a 40hp+ increase from a very poorely designed engine (!).

[GoLfMan]

bugger i was wrong again! ahh well *crawls back inside hole*

your car will be an absolute weapon on boost, but dont get caught in the wrong gear and off boost! should be sweet to see how it goes with the turbo set up

[velly_16v_cab]

P.S. A lot of the US and UK cars that apparently knock on 200hp with an $800 head job and KR cams need to remember that the early 16v power-up from Oettinger etc (with warm cams, great heads, and very nice exhausts) were only rated at around 175-180hp! The 190hp versions had 276 cams. I'd be more inclined to believe an engine dyno worth a few hundred grand than some bloke in a shed apparently getting a 40hp+ increase from a very poorely designed engine (!).

coming from the uk and being a 16v lover i can say yes there is a load of 16v's pushing out 180 BHP @ fly.
i have a mate who has built 2 2.0 16v's which both run over 185bhp and is also building a 2.1 (another mates 2.1 on twin 48's -pushed out over 200bhp)

it can be done...ive seen it

[Preen59]

Just for the record, the ABF block in the white car is pretty much standard. It just has fresh parts, ARP bolts and a decompression plate.

TBH, I've built it to see how much boost it'll take before blowing up. It's actually RPMs that kill a 16v anyway; they seem to take a lot of boost for a long time if they're kept around a 7k rev limit

This is one of the other reasons it costs so much to build a nice ITB'd engine: the cams you need to actually use all that extra intake capacity demand so many revs, and you can't get much more than 7.5k out of a stock bottom end, and a bit over 8k revs from hydraulic lifters.

You also need to rev high enough to actually get a decent power band. If you didn't rev, you'd want a 7spd 'box!

There are huge improvements to made outside of the engine anyway. Putting a 3.94:1 final drive in a 16v 020 (and most 02As) feels like you've got another 30hp and your flywheel has shed half its weight. You can't really do this in a big boost engine as the torque will light up all the gears - you have to keep the longer ratios so it comes on a bit more lazily (unless have AWD of course). Being able to build a gearbox with taller 1st and 2nd, and then tighter stacked 3, 4, 5, 6 would be the best of both worlds, but that would be $15,000.

As Preen says earlier, getting near 200hp is great fun a Mk1 anyway I've only turbo'd mine out of curiousity - if the truth be known, it'll be a slower car in a lot of areas due to the lower compression, gearing, and the lag!

I agree with all that. The early oettinger engines were a 1.6 though. Well i'm pretty sure they were.

Techtonics Tuning told me that standard 16v internals (same rods as the 1.6, 1.7, 1.8 and early 2.0) will handle 25 PSI or around 8000rpm respectively. The thing to remember with VW engines is that the RPM is deceiving. They have a MUCH longer stroke than say a honda or toyota, and are actually over-stroked really.

Engines start running into problems with pistons generally around a piston velocity of 25m/s (metres a second), from what i've hear'd off most engine builders, above that the thermal load on the side of the piston becomes too great, with the addition of the increasing reciprocating force and BANG.

So at 8000rpm a VW 86mm stroke 1.8 has a piston velocity of 22.9m/s, very high for standard cast pistons. Although i was told by TT 8500 would be ok on standard internals.

A Honda 1.8 VTEC 77mm stroke at 8000 rpm has a piston velocity of only 20.5 m/s. Fairly mild, so you could rev it to say 9500 before you would run into problems.

[Preen59]

I suppose i should tell you how to work out piston velocity.. It's pretty simple.

Piston velocity is simply the speed that the piston is traveling at, at a given RPM.

We'll go with nice round numbers here to keep it simple.

Smokin Joe's 58 valve 4 cylinder has a stroke of 80.0mm and he sets his limiter at 9000 RPM.

RPM is revolutions per minute and we want a value in seconds, so:
9000/60=150.

Remember that in one complete revolution the piston goes from Top Dead Centre to Bottom Dead Centre, and then back to the top, so:
2x80.0=160.

Now, every one second at 9000rpm the engine rotates 150 times, so:
150x160=24000.

24000 is a figure in millimetres and we want metres, so:
24000/1000=24.

This gives us a piston velocity of 24m/s (metres per second) at 9000rpm.

I hope i've explained that clearly, let me know if i haven't.

[aprr32]

If you want honest 200+hp,reliable and driveable just put a 20v turbo in.No opening the engine to do mods,just wind up the wind and enjoy 280 hp at the fly with driveability that my even grandmother can enjoy.I've been down the highly tuned, bad mannered and short lived na's road years ago and while it's fun for a while, driveability is everything these days.

[GoLfMan]

I suppose i should tell you how to work out piston velocity.. It's pretty simple.

Piston velocity is simply the speed that the piston is traveling at, at a given RPM.

We'll go with nice round numbers here to keep it simple.

Smokin Joe's 58 valve 4 cylinder has a stroke of 80.0mm and he sets his limiter at 9000 RPM.

RPM is revolutions per minute and we want a value in seconds, so:
9000/60=150.

Remember that in one complete revolution the piston goes from Top Dead Centre to Bottom Dead Centre, and then back to the top, so:
2x80.0=160.

Now, every one second at 9000rpm the engine rotates 150 times, so:
150x160=24000.

24000 is a figure in millimetres and we want metres, so:
24000/1000=24.

This gives us a piston velocity of 24m/s (metres per second) at 9000rpm.

I hope i've explained that clearly, let me know if i haven't.

nice and easy! thanks mate im going to find that useful

[Preen59]

Righteo BDA fans, cop this! This is a post on a US forum from a tuner in greece. He's building a VW 2.1 16v to produce atleast 1000hp.

Here's the thread: http://www.vwfixx.com/forums/index.php?showtopic=25719

Ok lets talk about engines. Lets compare some of the best engines with the vw 16v engine.

First when i built an engine i determine the purpose of the engine and the rpm bandwith that i will need the power. How many horsepower i will need and the engine time limit.(reliability).

Reliability and power is something completly diferent.

2 things makes an engine broke : piston velocity and piston aceleration.
When an engine have long stroke the piston velocity goes higher. Typicaly 25m/sec its the limit of a normal engine. The abrasion of the piston inside the engine is very important. So a vw 2ltr engine with 92,8 stroke have 25,1m/s at 8100rpm. If we need to work this engine to higher rpms we must reduce the stroke, for example: from 92,8 to 85 (1817cm3) at 8100rpm we will have 23m/s so we can go to 9000rpm that we will have 25,5 m/s piston velocity. Some guys think that displasment is better than higher rpms. Thats stupid. I prefer an 1.670cc engine that revs 12000rpm thank a 3ltr engine that works 7500rpms. This balance is absolutely calculatable. All the mater is the actual flow of eatch engine lbs/min.Lets see an example:
3ltr engine with 8,5 comp.ratio and 7500rpm limit with volumetric efficiency 82% will gave us 62lbs/min. A 1,7ltr engine with 11 comp.ratio and 12000rpm limit with volumetric efficiency 82% will gave us 70lbs/min. The things are clear.
The other thing is the piston aceleration. Its very important the type lenght of rod / stroke ratio. The vw 2ltr engine have 159/92,8 = 1,713
1,6 - 1,7 is bad engine with rpm limit until 7000rpm max.
1,7 - 1,8 is good engine that can revs 9000rpm.
1,8 - 2,0 is very good engine that can revs 12000rpms.
So vw engine with 1,713 have 30000m/sec2 acceleration piston velocity and piston position from TDC 50000m/sec2 acceleration. When this prices reduces the best lenght to stroke ratio we have. My engine now have 2.105 length to stroke ratio and gives me the benefit to rev it until 12700rpm with no problem. For example a cosworth engine that have 90,8mm piston 76mm stroke and 130mm rod its better engine from stock 2ltr vw because have at 10000rpm 25m/sec 1,710stroke ratio. But thats only the design of the engine. Design of the engine cant give us power but can alow us to rev the engine higher. Cylinder head makes the power. Some theories tells that an cylinder head with bigger valves is better. Thats almost inacurate.
Typical its true but in real fact is mistake.Lets see the theory.
Vw 1.8ltr kr head have 117cfm inlet and 91,2cfm exsaust.
Cosworth have 122cfm inlet and 95,9cfm axsaust.
Theory tell us:
CFM x No. of Cylinders x 0.43 = BHP
Vw 117cfm x 4 x 0.43 = 201.24 bhp.
Cosworth 122cfm x 4 x 0.43 = 209.84 bhp.
Cosworth intake valve is 35mm and vw 32mm.
Typicaly the cosworth head its better BUT lets see it in action:
All the matter of power is how much mixture can pass at the same period of time.
Lets compare the 2 engines with same parts exaclty:
Vw 32mm intake valve 8000rpm limit and 10mm valve lift.
Cosworth 35mm intake valve 8000rpm limit and 10mm valve lift.
Cosworth 131,14 m/s flow mixture.
Vw 140.86 m/s flow mixture.
Thats the real benefit of the vw engine that noone knows.
The cosworth have 1005.16 mm3 valve open, vw have 942.33 mm3 but thats nothing to do with power / flow mixture per sec.
These years i am searching all the kind of engines i ve spent many many hours compare eatch other. Cosworth, Opel Vauxhall XE 16v, 3Sgte st205, Mitsubishi evo. Cosworth is the best of all the above and its more easy to tune.A good engine is more cheap to make it better but a normal engine is most expensive and dificult to make it better.I ve spent thousants of $ and private time to compare all the engines and to make the normal vw engine propably the best of all. I can write for hours but i have limited time.



Spyros