# mk2 vr supercharged



## tjuvi1 (Apr 15, 2007)

I just finished puttin a v-9 supercharger and boost guage on the car. I see at idle vacuum is at -16 and the car only boost 2 pounds


----------



## slcturbo (Apr 19, 2010)

tjuvi1 said:


> I just finished puttin a v-9 supercharger and boost guage on the car. I see at idle vacuum is at -16 and the car only boost 2 pounds


At what rpm? What pulley is on the car?

Congrats. You are finding out the hard way why 99% of people go turbo. Centrifugal SC's don't make squat for boost in the low and mid range.


----------



## tjuvi1 (Apr 15, 2007)

Not looking for a high horsepower car just wanted alittle more power. Got the stage one set up. I thought the car was suppose to boost about 6 pounds with the supercharger


----------



## slcturbo (Apr 19, 2010)

tjuvi1 said:


> Not looking for a high horsepower car just wanted alittle more power. Got the stage one set up. I thought the car was suppose to boost about 6 pounds with the supercharger


Turbos aren't just for high HP applications. This is a horrible misconception.

You'll make 6psi at 7k rpm only. 

3k~1psi
4k~2psi
5k~3psi
6k~5psi
7k~6psi

Is that what you're seeing? If so it's normal. Turbo would have gone 6psi from 3-7k.

I've had both man. Just wish you would have asked me before you bought it. I could have saved you the frustration:beer: Sold mine and never looked back.


----------



## mk4vrjtta (Feb 3, 2007)

like slc said, at what rpm are you seeing 2psi?


----------



## Dave926 (Mar 30, 2005)

slcturbo said:


> At what rpm? What pulley is on the car?
> 
> Congrats. You are finding out the hard way why 99% of people go turbo. Centrifugal SC's don't make squat for boost in the low and mid range.


^^This


----------



## tjuvi1 (Apr 15, 2007)

I see, car is boosting 2 psi at 7k. I am thinking there is a vacuum leak somewhere, at idle guage reads 15-16 but my 1.8t at idle reads 20


----------



## slcturbo (Apr 19, 2010)

tjuvi1 said:


> I see, car is boosting 2 psi at 7k. I am thinking there is a vacuum leak somewhere, at idle guage reads 15-16 but my 1.8t at idle reads 20


Or belt slip.


----------



## mk4vrjtta (Feb 3, 2007)

most likly it is belt slip. also, make sure you dv isnt sticking open, its happened to me before :thumbup:


----------



## V-dubbulyuh (Nov 13, 2005)

slcturbo said:


> Turbos aren't just for high HP applications. This is a horrible misconception.
> 
> You'll make 6psi at 7k rpm only.



Why centrifugal S/C suck.


----------



## mk4vrjtta (Feb 3, 2007)

V-dubbulyuh said:


> Why centrifugal S/C suck.



just another opinion.


----------



## tjuvi1 (Apr 15, 2007)

mk4vrjtta said:


> most likly it is belt slip. also, make sure you dv isnt sticking open, its happened to me before :thumbup:


I think this is problem.


----------



## V-dubbulyuh (Nov 13, 2005)

mk4vrjtta said:


> just another opinion.


Oh buddy I got proof... You want to see some performance curves for centrifugal chargers vs turbos? I would not classify it as opinion... the efficiency of a rotary blower occurs at peak RPM. It's compression is proportional to your crank... you don't have a wastegate equivalent helping you to maintain a given boost.

I get the concept of not wanting a high hp output car. That however is independent of efficiency. My point is that there is more than one way to produce 7psi. You can achieve it at one RPM (SC) or you can have it across a wider RPM range (turbo).

My opinion.


----------



## slcturbo (Apr 19, 2010)

V-dubbulyuh said:


> Why centrifugal S/C suck.



For 4 and 6 cyl. absolutely. I had one and don't miss one thing about it. Some avoid turbo b/c it's for "high hp applications"-misconception. 

At 7psi my turbo was 2x as fun as my 12psi SC kit ever was. For any street car it's about torque over a usable powerband. That's what makes a car fun. Centrif SC's fail at the torque part and the powerband part.


----------



## mk4vrjtta (Feb 3, 2007)

V-dubbulyuh said:


> Oh buddy I got proof... You want to see some performance curves for centrifugal chargers vs turbos? I would not classify it as opinion... the efficiency of a rotary blower occurs at peak RPM. It's compression is proportional to your crank... you don't have a wastegate equivalent helping you to maintain a given boost.
> 
> I get the concept of not wanting a high hp output car. That however is independent of efficiency. My point is that there is more than one way to produce 7psi. You can achieve it at one RPM (SC) or you can have it across a wider RPM range (turbo).
> 
> My opinion.


im not going to get in the supercharger/turbo debate, but how is a centrifugal supercharger inefficient? just because it doesnt make boost the way a turbo doesnt mean its inefficient. the v9 ruined the "cool" vr6 supercharged reputation. it's too small and just plan sucks for most people. a vr with a 1400cfm centrifugal blower at 15+psi would make almost anyone smile. in fwd cars centrifugal s/c are in MY OPINION the best FI (as long as the blower is of sufficeint size), because of their power delivery. traction is there along with the power. and yes ive ridden turbo, roots, and centrifugal FI cars. if its awd then yes a turbo is the way to go, but again, just my opinion :thumbup:


----------



## V-dubbulyuh (Nov 13, 2005)

mk4vrjtta said:


> im not going to get in the supercharger/turbo debate, but how is a centrifugal supercharger inefficient? just because it doesnt make boost the way a turbo doesnt mean its inefficient. the v9 ruined the "cool" vr6 supercharged reputation. it's too small and just plan sucks for most people. a vr with a 1400cfm centrifugal blower at 15+psi would make almost anyone smile. in fwd cars centrifugal s/c are in MY OPINION the best FI (as long as the blower is of sufficeint size), because of their power delivery. traction is there along with the power. and yes ive ridden turbo, roots, and centrifugal FI cars. if its awd then yes a turbo is the way to go, but again, just my opinion :thumbup:


I'm not going to belabor the point further after this post... stick to your supercharger. I have provided enough detail in the previous post to explain why it is inefficient. You like superchargers which is cool, that is a preference... basically an opinion. The characteristic that superchargers do NOT generate their max rated boost level until peak RPM is a *fact*. Point being that your earlier RPM band is essentially wasted trying to achieve the SC's max output. Do you or anyone else typically drive around at redline? I've had "low boost" cars and even at a mild 6 psi I rather have it available across a wider rpm band. This is my argument for efficiency. Whether the power is usable due to traction, broken trannys, etc is irrelevant, I am referring to the efficiency of the force induction system itself.


----------



## slcturbo (Apr 19, 2010)

V-dubbulyuh said:


> I'm not going to belabor the point further after this post... stick to your supercharger. I have provided enough detail in the previous post to explain why it is inefficient. You like superchargers which is cool, that is a preference... basically an opinion. The characteristic that superchargers do NOT generate their max rated boost level until peak RPM is a *fact*. Point being that your earlier RPM band is essentially wasted trying to achieve the SC's max output. Do you or anyone else typically drive around at redline? I've had "low boost" cars and even at a mild 6 psi I rather have it available across a wider rpm band. This is my argument for efficiency. Whether the power is usable due to traction, broken trannys, etc is irrelevant, I am referring to the efficiency of the force induction system itself.


This is the heart of it. The peak boost/peak power comparisons that are the norm are pretty much irrelevant for street cars. Like you said, who drives around at 6-7k on the street? Look at boost, powerband, over the entire rpm range and in particular in the mids ~3-5k which you're going to use alot more on the street than 6-7k.

The built in traction control and ease on drivetrain components is a good point, but you have more traction because you aren't making any power there. I mean NA gets better traction than SC so why even put a SC on the car. 

Honestly, and I say this to try and save people the headache. At least drive a mild ~6-9psi turbo kit on a VR before you buy a SC. Don't screw yourself to be different or because you didn't have all the information.


----------



## vwmaniac16vr6 (Nov 17, 2004)

the v1 is the charger to have i loved mine, ran 13psi daily with no head spacer and i really liked the linear pull. the v9 is much more problematic and i agree it ruined the superchargers reputation sorry i dont have much imput for the op except check for rubber shaving and maintance history of the blower.


----------



## slcturbo (Apr 19, 2010)

vwmaniac16vr6 said:


> the v1 is the charger to have i loved mine, ran 13psi daily with no head spacer and i really liked the linear pull. the v9 is much more problematic and i agree it ruined the superchargers reputation sorry i dont have much imput for the op except check for rubber shaving and maintance history of the blower.


Yeah I mean I did enjoy mine (V9) ~12psi. If it weren't for the V9 blowing at 6kmiles I probably wouldn't have nearly as bad a taste in my mouth.

For me it was the annoyance of revving the car to 5-7k to have any real fun. Prime example. I'm on the highway cruising at ~2.5-3k. I punch it to pass etc. Immediately I see ~10psi rising to 15psi by 4k, car I was passing is 3 car lengths behind. That's all while staying in 5th gear. That same scenario in a SC car is MUCH different.


----------



## Love2Spool (Sep 10, 2010)

super chargers are for v8's...when they start putting v8's into jetta's and gti's then ill consider a supercharger


----------



## mk4vrjtta (Feb 3, 2007)

Love2Spool said:


> super chargers are for v8's...when they start putting v8's into jetta's and gti's then ill consider a supercharger


stupid comment :facepalm:


----------



## slcturbo (Apr 19, 2010)

mk4vrjtta said:


> stupid comment :facepalm:


Not really. I have to agree. I mean if somebody likes their SC on a 4 or 6cyl I'm not hating on them. Enjoy it. However as a general rule:

4 and 6cyl= Turbo
8Cyl= NA, SC, or Turbo

You just can't make any real usable torque on a small displacement motor without a turbo. To my knowledge anyway.


----------



## mk4vrjtta (Feb 3, 2007)

slcturbo said:


> Not really. I have to agree. I mean if somebody likes their SC on a 4 or 6cyl I'm not hating on them. Enjoy it. However as a general rule:
> 
> 4 and 6cyl= Turbo
> 8Cyl= NA, SC, or Turbo
> ...


i dont see how this is a "rule"  and if you want usable torque on the street a roots blower is the way to imo. the fun factor is def there . boost as soon as you want it and anywhere in the rpm's. also, eaton has some newer blowers that have the effiencieny close to that of a turbo.


----------



## slcturbo (Apr 19, 2010)

mk4vrjtta said:


> i dont see how this is a "rule"  and if you want usable torque on the street a roots blower is the way to imo. the fun factor is def there . boost as soon as you want it and anywhere in the rpm's. also, eaton has some newer blowers that have the effiencieny close to that of a turbo.


- Not a rule. My opinion based on the fact that a V8 already makes decent power/torque on it's own.

-Is there a roots kit for a 12V? My comments are related to centrifugal SC's bc that's what's made for 12V's.

I'll never put a SC on a 4cyl or 6cyl again. NA for simplicity or turbo for power.


----------



## KubotaPowered (Jan 27, 2005)

It is a fact, the SC has more of a "fuss factor" to it, but I when it comes down to usable power and something that's fun to drive, the 300hp SC VR gets my vote.


----------



## Love2Spool (Sep 10, 2010)

mk4vrjtta said:


> stupid comment :facepalm:


stupid comment? find me any ANY supercharged 4 or 6 cylinder making some serious power. now find me a supercharged v8 that ISNT making serious power lol. superchargers are for v8s man.



mk4vrjtta said:


> i dont see how this is a "rule"  and if you want usable torque on the street a roots blower is the way to imo. the fun factor is def there . boost as soon as you want it and anywhere in the rpm's. also, eaton has some newer blowers that have the effiencieny close to that of a turbo.


 please find me a roots kit ofr a vr..or an aba, or a 16v...or a honda, or something that isnt a FKN V8!... your fighting a losing battl;e...you hadd forced induction to make power...anyone who tells me otherwise is retarded..and turbo's are just better at making power on smaller applications....and bigger aplications for that matter...lets not talk about the turbo's ability to make full boost early in the power band and also the ability to turn the boost down or up without doing anything but twisting a knob. dude superchargers BLOW..period..for efficiency, for reliablility, for fun, for making powe...turbo's are BETTER..its not an opinion, nor a rule, nor a suggestion...its a FACT. bro if you wanna supercharge your lawn mower i wouldnt care its up to you, but im still gunna say a turbo would have been a better option for your john deere:thumbup:


----------



## Love2Spool (Sep 10, 2010)

listen to waht you just typed "efficiency close to that of a turbo" lol your saying a turbo is better and you dont even know it


----------



## slcturbo (Apr 19, 2010)

KubotaPowered said:


> It is a fact, the SC has more of a "fuss factor" to it, but I when it comes down to usable power and something that's fun to drive, the 300hp SC VR gets my vote.


Really? Not arguing by any means:beer:

I had a ~280whp SC kit (12psi) and my VRT was making 319whp at 12psi intercooled.

Comparing those two setups I have to say there was no comparison fun wise on the street. Peak torque was ~320 for the turbo and 236 for the SC, but the real story was the power band. I have both dynos somewhere but not overlaid unfortunately. At 3 and 4k the turbo was making so much more hp and tq than the SC. 

1/4 mile times for anyone interested. Same track, roughly same weight car, same 30# inj., same C2 30# chip, same fuel, both kits at 12psi. Turbo was intercooled. SC was not.

[email protected]

[email protected]

The turbo was just so much faster at the same boost, had almost 100ft-lbs more torque, and made more hp and torque over a much broader rpm range. The 1/4 comparison is actually much closer than the street comparison because in the 1/4 I'm mainly in the 5-7k range so the SC has a prayer. Do some 3-5k highway pulls and it's night and day.

Again just my #'s, opinions on both setups. Not trying to argue with you:heart:


----------



## Love2Spool (Sep 10, 2010)

ill take the turbo thank you very much


----------



## KubotaPowered (Jan 27, 2005)

slcturbo said:


> Really? Not arguing by any means:beer:
> 
> I had a ~280whp SC kit (12psi) and my VRT was making 319whp at 12psi intercooled.
> 
> ...


I'll agree the turbo makes more power, 99.9% of the time it will. However, a 350whp VRT has no traction in 2nd and most of 3rd gear. With the blower, the power builds linear to engine speed, every time, cutting the loss of traction significantly. The VRT Jetta has dropped compression, a humongous 1.06 hotside and is a dog out of boost. The SC Jetta on the otherhand has 9.5:1 compression, V1 and 2.87in pulley. Just personal preference given the two vehicles.


----------



## slcturbo (Apr 19, 2010)

KubotaPowered said:


> I'll agree the turbo makes more power, 99.9% of the time it will. However, a 350whp VRT has no traction in 2nd and most of 3rd gear. With the blower, the power builds linear to engine speed, every time, cutting the loss of traction significantly. The VRT Jetta has dropped compression, a humongous 1.06 hotside and is a dog out of boost. The SC Jetta on the otherhand has 9.5:1 compression, V1 and 2.87in pulley. Just personal preference given the two vehicles.


I used to make the same argument, but you lose traction because you make more power/torque so it's like you are losing on traction with the turbo due to power you aren't able to make with the SC. I mean I had traction in first NA, but spun up top with the SC. That's what happens when you make more power which is why you went FI to begin with. Turn down the boost and enjoy the broad powerband.

Similar to saying I don't want that million dollar lottery payout b/c I have to pay taxes on it. 

Also compare similar setups. Turbo doesn't need a huge hotside or lowered compression to make ~300-320whp which is as much if not more than any V9 has made. I had no traction in first but had full traction in 2nd at ~10-11psi with a 3.65 final.


----------



## Love2Spool (Sep 10, 2010)

KubotaPowered said:


> ... However, a 350whp VRT has no traction in 2nd and most of 3rd gear. ....


please tell me what VRT you kno with 350whp that has no traction for most of 3rd?:screwy: please im begging you cuz that makes no sense. vr6's are torque motors but now your talkin crazy. my co-workers built ws6 has almost 400 to the wheel and way over 400 torque and he has zeroc traction 1st and 2nd but chirps 3rd then grabs. and his car is a 6 speed. ive been in a 6spd vrt with more tha 350whp, open diff, and regular ass street tires so it spun like a bitch but not in 3rd. i call BS


----------



## slcturbo (Apr 19, 2010)

Love2Spool said:


> please tell me what VRT you kno with 350whp that has no traction for most of 3rd?:screwy: please im begging you cuz that makes no sense. vr6's are torque motors but now your talkin crazy. my co-workers built ws6 has almost 400 to the wheel and way over 400 torque and he has zeroc traction 1st and 2nd but chirps 3rd then grabs. and his car is a 6 speed. ive been in a 6spd vrt with more tha 350whp, open diff, and regular ass street tires so it spun like a bitch but not in 3rd. i call BS


Agreed. I mean barring 30-40 degree temps when summer tires get hard and you have major traction issues.

No lie. 15-16psi this year ~350whp at the beach this summer and only slightly chirped them in 2nd with two people in the car. Full traction in 3rd. I never spin or chirp 3rd at all at 15psi ~350whp unless it's near or below freezing out.


----------



## Love2Spool (Sep 10, 2010)

yea man it just doesnt add up...i hate when ppl talk about stuff they dont know....


----------



## KubotaPowered (Jan 27, 2005)

Love2Spool said:


> please tell me what VRT you kno with 350whp that has no traction for most of 3rd?:screwy: please im begging you cuz that makes no sense. vr6's are torque motors but now your talkin crazy. my co-workers built ws6 has almost 400 to the wheel and way over 400 torque and he has zeroc traction 1st and 2nd but chirps 3rd then grabs. and his car is a 6 speed. ive been in a 6spd vrt with more tha 350whp, open diff, and regular ass street tires so it spun like a bitch but not in 3rd. i call BS


Why are you comparing a FWD to a RWD? Stop there. If you want to see what in talking about, come down to Tucson and I'll show you. Ill turn the boost down and take you for a spin and show you traction problems.


----------



## Love2Spool (Sep 10, 2010)

plese post vids of dyno and then a run in car..i wanna see a 350whp vr spinning thru 3rd...


----------



## Love2Spool (Sep 10, 2010)

ive been in a couple vrts man and they werent doing what your saying..hows that, FWD to FWD..SAME FKN ENGINE...bro you dont make sense


----------



## Love2Spool (Sep 10, 2010)

bro your statement was that a 350whp vr spins almost all of 3rd..i wanna see that not your dyno numbers. i dont care about your dyno numbers. and i said it 2 times already..forget the ws6, ive been in vrs with more than 350whp and they didnt have traction issue's in 3rd. so please move on to the real point that your suppose to be proving and stop talking about my comparison


----------



## KubotaPowered (Jan 27, 2005)

If you want a back to back dyno run then run on the street I don't have it and I won't go out and make the pulls to make some guy on the internet happy. Like I said, if you want to come take a ride, come on down, I'll give you directions, until then continue trolling the forums


----------



## Love2Spool (Sep 10, 2010)

"continue trolling the forums"(in my biggest flaming ***** voice)lol..bro your wrong..period. until you prove otherwise go drive your VR into a wall.lol


----------



## slcturbo (Apr 19, 2010)

Doesn't really matter what spins what where. 

You like centrifugal SC's then run one. However there is no comparison between the 2. 

Quickest SC VR ever was ~11.65 on standalone. I almost got there on a simple 30# chip, stock motor, stock MAF setup and was actually faster. Think I trapped 119mph. That says alot.


----------

