# 8v vs. 16v?



## wheeltowheel (Jun 19, 2007)

How much extra performance does the 16v offer opposed to the 8v?
I am talking stock scirocco engines


_Modified by wheeltowheel at 9:30 PM 9-11-2007_


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## Syco Stang (Dec 7, 2002)

Oh man, try searching dude. You're going to get flamed for this post. All the info you want, can be found under search.
Here's a hint, try doing the same search twice... the second time under the "archived" selection and you will get lots of hits under 8v vs 16v.
SS


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## jxforxjeff (Jun 23, 2004)

*Re: 8v vs. 16v? (wheeltowheel)*

lock this thread. its going to get ugly...


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## Longitudinal (Nov 13, 2004)

*Re: 8v vs. 16v? (jxforxjeff)*


_Quote, originally posted by *jxforxjeff* »_lock this thread. its going to get ugly...









No it won't. 8V is a good forum with mature users. We love our enignes and can objectively evaluate the differences between 8V and 16V. Right, boys?


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## veedub1991 (Mar 16, 2006)

*Re: 8v vs. 16v? (Longitudinal)*

Check that out

http://forums.vwvortex.com/zerosearch


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## wheeltowheel (Jun 19, 2007)

ok, this is what I have found...8v's are more reliable, faster off the line, easier to work on, are lighter (better handling), and get better gas milage.
while...
16v's have a cool body kit (sciroccos), take over 8v's after around 3rd gear, and look better in the engine compartment.
Any objections?


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## wheeltowheel (Jun 19, 2007)

*Re: 8v vs. 16v? (wheeltowheel)*

testing picture...








_Modified by wheeltowheel at 4:08 PM 9-6-2007_

_Modified by wheeltowheel at 4:08 PM 9-6-2007_

_Modified by wheeltowheel at 4:09 PM 9-6-2007_

_Modified by wheeltowheel at 4:09 PM 9-6-2007_


_Modified by wheeltowheel at 4:10 PM 9-6-2007_


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## wheeltowheel (Jun 19, 2007)

*Re: 8v vs. 16v? (wheeltowheel)*

HA! IT WORKED!!!!!


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## 89wolfsburg (Mar 14, 2001)

*Re: 8v vs. 16v? (wheeltowheel)*

8V: 
good low end torque(although, there are race engines that rev to the moon)
Great street engine
Reliable as a stone
simple and fairly cheap to modify
16V:
All upper end power
not as good as an 8V for street driving(IMO)
expensive to modify
fragile(compared to an 8V)
Much easier to get big power
more advanced injection system
VW&P compared a stock 1.8 16V to a mild 2.0 8V engine in two identical 81 sciroccos, and they much preferred the 8V lump(it was faster too).
I am sure you will get the complete opposite from the 16V forum, so take anything said in either forum with a grain of salt.


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## mittimj (Dec 27, 2006)

I ran a mildly modded 1.8l 8v in my race car then a 1.8 16v with some of the same mods but mabie not as many.
Over all I prefered the 8v because it had more pull of the corners and was easier to work on. 
But I will say there was a 2.0 16v in another racers car, same mild mods. that thing goes like a raped ape compared to anything I have run. lol


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## MkIIRoc (Feb 20, 2005)

stock 16v's horsepower taper off not far from the stock 8v's. The 16v is not a screamer in stock form, and neither is the 8v.








16v peaks at about 5600 rpm
Granted, the 8v falls flat on it's face, while the 16v gradually tapers off.








8v peaks at about 5500
Look at eurotrashrabbit's setup. He drives his on the street and probably makes +/- the same power as my 8v race engine. 
Trash's








Mine


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## apavlov (Dec 4, 2005)

Notice that on the plots, the 16v still has more torque than the 8v almost throughout the entire range.
And then the 16v still has 100 Ft-lbs at 6500, whereas the 8v probably won't ever get there in a reasonable amount of time. I drive a counterflow 8v, so my torque tapers even worse than that.
People always say that the 8'v are a lot tourqier than the 16's down low, but I was curious if that was because of the impression of the 16v's top end that you thought it had little to offer down low, where in fact it has just as much, if not more.


_Modified by apavlov at 12:54 PM 9-7-2007_


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## 89wolfsburg (Mar 14, 2001)

*Re: (apavlov)*

I can only talk about the one 16V I drove, and the comments from the editors of VW&P.
I drove an 87 Scirocco 16V(123HP), and it was weak in the low end, and the power did not seem to come on until almost 4000rpm.
The editors said in two identical cars other than the motor, the 2.0 8V was faster than the 1.8 16V.
As for those graphs, I don't think that 16V is stock. They are comparing stock manifolds to a header, and to make it look better, I would bet they tuned that motor to get a good result.(they don't even mention the engine size)


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## Peter Tong (Jun 17, 1999)

*Re: (89wolfsburg)*

Here's some data:


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## Longitudinal (Nov 13, 2004)

*Re: (Peter Tong)*

Peter's dyno graph shows what I have heard for years--that the 16V really isn't as dead at lower RPM as people think it is. It's an excellent engine, but so is the 8V. If you're looking for the most NA horsepower possible, then you want 16V. But up to 120-130 HP or so, an 8V is cheaper if you already have an 8V. Beyond that point, you'd be looking at investing money in better valves and a port job, and that gets expensive fast. Of course, when you get to that point on a 16V it gets even more expensive even faster.


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## Peter Tong (Jun 17, 1999)

*Re: (Longitudinal)*

Hi Jonathan,
That is actually Techtonics graph (gotta give it where its due







). I think its kind of deceptive in one way though, and that is at part throttle the 8v will be making a higher percentage of its max torque down low vs the 16v due to the higher port velocity...
The problem is no one seems to dyno at 1/2 throttle, 3/4 throttle etc... its always at full throttle (understandably though). Doing it the multiple throttle way would give a much better idea of how the car would actually perform on the road. I wouldn't doubt if the 8v is making 20% more torque vs the 16v at 3/4 throttle in the 2000-3000 range... 
Just my two cents worth...
Peter T.


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## 8valvinsleeper (Jul 13, 2007)

*Re: 8v vs. 16v? (wheeltowheel)*

i think that one factor that really changes up the powerband of the 16v is the plenum. The fact that they have longer intake runners gives for great high end power but they have less torque down low and their throttle response isnt as snappy as an 8v (IMO). When i first got my 1.8 8v (RV), it had a really balanced powerband and had no real spikes or unbelievable changes of the powerband. I upgraded the intake, cam, porting, exhaust well just about the entire cylinder head and everything directly connected to it (minus the block). The powerband began to change. Right now, it needs some sort of forced induction. The intake vacuum is actually too low and the air doesnt have enough velocity coming into the combustion chamber. It has a pretty smooth powerband up to 3800 rpm. For example, in a particular gear, it could take 3 seconds to go from 1000rpm to 4000 rpm. But then it only takes 1 second to go from 4000 rpm to 6000. And it is true that you can get more power at lower rpm by going 3/4 throttle as opposed to 100%. The air in the intake manifold needs to have the right balance between pressure and velocity to get the best torque/hp readings.


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## wheeltowheel (Jun 19, 2007)

*Re: 8v vs. 16v? (8valvinsleeper)*

that's very interesting


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## Jettaboy1884 (Jan 20, 2004)

*Re: (Peter Tong)*


_Quote, originally posted by *Peter Tong* »_
The problem is no one seems to dyno at 1/2 throttle, 3/4 throttle etc... its always at full throttle (understandably though). Doing it the multiple throttle way would give a much better idea of how the car would actually perform on the road. I wouldn't doubt if the 8v is making 20% more torque vs the 16v at 3/4 throttle in the 2000-3000 range... 
Just my two cents worth...
Peter T.

Peter, could you please elaborate on your above statement?
The reason I ask is because I have always wondered if the engine is making peak power thru the rev range at wide-open-throttle, or if the engine would make more power by opening the throttle progressively, as the RPM's climb.
For example: If you floor the pedal at low RPM's, it almost seems that the engine is getting too much air, and doesn't pull very hard until the RPM's climb up to the point where the engine actually _needs_ that much airflow...
I've driven a 1.8L 16v and a 1.8L 8v back to back, and even though the graphs say the 16v has a similar torque curve, I could swear the 8v just feels more torquey. (and the 16v feels gutless at low RPM's)

What are your thoughts?


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## secondgen (Jan 9, 2004)

*Re: (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_The reason I ask is because I have always wondered if the engine is making peak power thru the rev range at wide-open-throttle, or if the engine would make more power by opening the throttle progressively, as the RPM's climb.
For example: If you floor the pedal at low RPM's, it almost seems that the engine is getting too much air, and doesn't pull very hard until the RPM's climb up to the point where the engine actually _needs_ that much airflow...

I agree with this as well.
I've run faster times at the drag strip when progressively opening the throttle and not just snapping to WOT on every shift. That makes me think that if i were to throw it back on a dyno, and run a progressive, half throttle and WOT runs, i'd almost put money on the progressive one turning out better.
I've thought about this for some time now, and am just waiting on getting the rig back on a dyno to make some solid conclusions.


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## Peter Tong (Jun 17, 1999)

*Re: (Jettaboy1884)*

Naturally aspirated, I can't see the motor ever getting enough...until its flow limit its a ravenous creature








If your engine management is up to snuff, then the motor is going to make as much as possible with what air your throttle will let it have. So opening your throttle progressively would actually not be best for torque over that rpm range prior to opening it fully. For best power you want the manifold pressure to be as close to atmospheric as possible.
The 8v ports have alot less volume, the depression from the cylinders is the same as the 16v but the ports come up to their max potential flow earlier than the 16v port... so the velocity will be higher at a lower rpm = better cylinder filling = better torque at that lower rpm. At part throttle flow low rpm, will still be proportionately faster than the 16v head as well...
I drive 95% part throttle anyways on the street, so I like a motor that "feels good" in the low to mid range at part throttle.
All the above is probably why I like twin screw superchargers... instantaneous cylinder filling at any rpm (and esp low rpm)... driveability is nuts, and you don't have a jekyll and hyde motor having to wait for boost (or hoping you are in the right gear when you feel like being flung back)...
Hope that helps a little..
Peter T.


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## The_Hamster (Jul 31, 2000)

*Re: (Peter Tong)*

16v is slightly less reliable from the engine itself standpoint in my experience. But that's a slight for sure. More lifters to clack, dizzy o-ring leaks, etc. But nothing big at all. 
The 16v is far more fun to drive around however IMO in stock form. Having driven the same car with an 8v swapped out for a 16v I can say the 9A 16v was far more entertaining.
I'm also not a big fan of the CIS-Motronic that came with the 9A engines.


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## veedub1991 (Mar 16, 2006)

*Re: 8v vs. 16v? (8valvinsleeper)*


_Quote, originally posted by *8valvinsleeper* »_*i think that one factor that really changes up the powerband of the 16v is the plenum. The fact that they have longer intake runners gives for great high end power but they have less torque down low and their throttle response isnt as snappy as an 8v (IMO).* When i first got my 1.8 8v (RV), it had a really balanced powerband and had no real spikes or unbelievable changes of the powerband. I upgraded the intake, cam, porting, exhaust well just about the entire cylinder head and everything directly connected to it (minus the block). The powerband began to change. Right now, it needs some sort of forced induction. The intake vacuum is actually too low and the air doesnt have enough velocity coming into the combustion chamber. It has a pretty smooth powerband up to 3800 rpm. For example, in a particular gear, it could take 3 seconds to go from 1000rpm to 4000 rpm. But then it only takes 1 second to go from 4000 rpm to 6000. And it is true that you can get more power at lower rpm by going 3/4 throttle as opposed to 100%. The air in the intake manifold needs to have the right balance between pressure and velocity to get the best torque/hp readings. 
 
I think you have that backwards. Longer intake runners give better low end tq. While shorter/straighter intake runners are for high RPM power. This is why they make ITB's and short runner intake manifolds. They allow more air to flow through due to the air having to travel less distance.


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## secondgen (Jan 9, 2004)

*Re: 8v vs. 16v? (veedub1991)*


_Quote, originally posted by *veedub1991* »_ 
I think you have that backwards. Longer intake runners give better low end tq. While shorter/straighter intake runners are for high RPM power. This is why they make ITB's and short runner intake manifolds. They allow more air to flow through due to the air having to travel less distance. 

Beat me to it. http://****************.com/smile/emthup.gif


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