Big Turbo Kits?

[wezlo]

Hey, Im planing to buy a BT kit real soon, I just dont know who to go with. Its alot of money to drop, and whos to say whos kit is better? What do you guy and girls think about this, awe, apr, VF, who else? Did anyone come out with a gt30 kit? Im having trouble desiding, i wanna buy it right after christmas. Its just so much money wise, Some company has to really win me over on it i guess.

Thanks ahead of time for your opinions


Matt

[Zebman]

If I had a job and wasn't in school i'd wait and buy the AutoSpeed kit, it uses a GT30.

[a4mafia(Red)]

talk to mike hood or issam.....

[Keith@APR]

Hey, Im planing to buy a BT kit real soon, I just dont know who to go with. Its alot of money to drop, and whos to say whos kit is better? What do you guy and girls think about this, awe, apr, VF, who else? Did anyone come out with a gt30 kit? Im having trouble desiding, i wanna buy it right after christmas. Its just so much money wise, Some company has to really win me over on it i guess.

Thanks ahead of time for your opinions


Matt

Matt,

Here is a link to our Stage 3 release thread on this forum. Didn't know if you had seen it yet or not.

http://www.audizine.com/forum/showthread.php?t=250803

Let me know if you have any questions. I will follow up with this thread periodically or you can send me a pm.

Keith

[wezlo]

apr seem a little to conservative for my taste, i dont daily drive my car really. i drive the volvo to work so, if im gonna spend the money id rather go big and get the full effect of the what the 2.0 block has to offer..... am i wrong?

[Wizard-of-OD]

We have GT3076R kits available.Send me a PM to discuss this further.

[Mike@APR]

apr seem a little to conservative for my taste, i dont daily drive my car really. i drive the volvo to work so, if im gonna spend the money id rather go big and get the full effect of the what the 2.0 block has to offer..... am i wrong?

Wezlo:

The B7 Stage 3 kit from APR is not conservative at all for pump gas (93 octane). You must remember, these cars have a 10.3:1 compression and are less tolerant to just turning the boost up and advancing the timing. If we ran any more boost or timing on the production Stage 3 with 93 octane, we would get dangerous levels of knock that would not be good for your pistons (think melted metal). Also, with the tall gearing in the 6-speed B7, a 2871R is plenty big. That is unless you want your car to spool long after 4000 RPM. With a 3800lb car and tall gearing, the car will be very laggy.

If you want to build a dyno queen or single purpose drag racer, then I have no argument for you. But if you want to enjoy the car, I would not suggest a 3076 on pump gas. No offense to anyone offering that kit but I drive on the 2871R all day and have experimented with a 3071R on the same car and when running 93 octane and staying within the factory map sensor limits, the 2871R is a great setup. We are also currently tuning for 100 octane fuel so if you want big numbers, they are coming shortly.


**Stands on Soap Box**
Also, sorry for saying this but I want to break the misconseptions about turbos. Some might say that having a 3076 instead of a 2871R will get you more air flow and therefore more power but this is not true and is not being explained correctly. So many assumptions are made in this statment and so many details left out. Neither of these turbos has any trouble fully supplying the 2.0T FSI at the limit of the factory MAP sensor (~22 PSI) out to 7500RPM. So air flow is not a problem for either of these two turbos on this engine. So let's fix boost at 22 PSI for this argument and consider that neither of these turbos has any trouble meeting the air flow demands of the 2.0T FSI. Now think of air trying to flow through a hole. If you have 22 PSI of air driven by a pump going through a 1-inch hole with Pump A and then you have 22 PSI of air going through a 1-inch hole with Pump B...YOU HAVE THE SAME AMOUNT OF AIR FLOW. The hole in this argument is the engine (head, cylinders, etc.)

The only difference there may be is that Pump B may be more efficient at this pressure level and flow rate. Since this is air we are talking about and it is compressible and has a variable density, some would argue that there will be more air molecules available because it's a denser/cooler charge. This is true. But both turbos are heating up the air greatly so it's not like you have some significantly cooler air that doesn't require an intercooler. We are talking about a few percentage points of efficiency, if that much. So, the argument for the 3076 is that it is more efficient at the top end and has a slightly greater amount of air molecules in the hot compressed air before the intercooler.

Great...right? Not when you consider that you lost over 1000 RPM of spool time and you have the increased inertia of spinning up this more massive turbo. Not when you consider that you are constantly downshifting to get any acceleration out of the car. Not when you consider that if you are using the factory map sensor on pump gas, you won't be making any more power (safely, that is). Now, if you are going way outside of the parameters I have mentioned (map sensor, pump gas, etc.), the 3076 will have its advantages at the top end but at the sacrifice of drivability in the low end.

Our 2871R kit hits full boost (~21 PSI) on pump gas at 3500RPM. I don't think this is conservative at all. I think this is driveable. Like I said, if you plan to do build a single purpose car or go above the factory map sensor limits, then a bigger turbo might be the answer. But if you are planning on running pump gas and keeping your factory map sensor intact, I think the 2871R is the perfect setup for the B7 and it's taller gearing.

Just my $0.02.

**Steps down from Soap Box**

[b00st]

hopefully this doesn't turn into company debate/war.

when i think massive turbo.......T78/T88s come to mind....not so much 2871 or 3076. but thats just me.

[eMacPaul]

I will readily admit to my ignorance regarding turbos, but aren't there folks with the stock turbo already hitting 21 PSI on their REVO tunes? What's the advantage of a BT at all if you're going to stay only at 21?

[Mike@APR]

hopefully this doesn't turn into company debate/war.

when i think massive turbo.......T78/T88s come to mind....not so much 2871 or 3076. but thats just me.

Not my intent at all. And when you think of big turbos, remember that it's relative to the engine parameters.

[Mike@APR]

I will readily admit to my ignorance regarding turbos, but aren't there folks with the stock turbo already hitting 21 PSI on their REVO tunes? What's the advantage of a BT at all if you're going to stay only at 21?

These ECU upgrades are hitting 21psi for a short spike. The APR Stage 3 is holding 21 psi from 3500 RPM to 7100 RPM. This is because the factory turbo is too small to keep this pressure level and flow rate throughout the entire RPM band. Not to mention all the other changes in a Stage 3. It's all about balance and properly sizing the turbo for the application. I'll explain more later when I dont't have to type this on my iPhone.

[wezlo]

hmmm you put up a good argument mike, I do like that I have a huge company behind the product. So if I bought the kit would I have to bring it to a Apr dealer to get it flashed ... It's a hour away how will I be able to drive there with a stage 2 flash not 3?

[ray-ray]

good explanation, and props to you if you did type this on your iPhone

Wezlo:

The B7 Stage 3 kit from APR is not conservative at all for pump gas (93 octane). You must remember, these cars have a 10.3:1 compression and are less tolerant to just turning the boost up and advancing the timing. If we ran any more boost or timing on the production Stage 3 with 93 octane, we would get dangerous levels of knock that would not be good for your pistons (think melted metal). Also, with the tall gearing in the 6-speed B7, a 2871R is plenty big. That is unless you want your car to spool long after 4000 RPM. With a 3800lb car and tall gearing, the car will be very laggy.

If you want to build a dyno queen or single purpose drag racer, then I have no argument for you. But if you want to enjoy the car, I would not suggest a 3076 on pump gas. No offense to anyone offering that kit but I drive on the 2871R all day and have experimented with a 3071R on the same car and when running 93 octane and staying within the factory map sensor limits, the 2871R is a great setup. We are also currently tuning for 100 octane fuel so if you want big numbers, they are coming shortly.


**Stands on Soap Box**
Also, sorry for saying this but I want to break the misconseptions about turbos. Some might say that having a 3076 instead of a 2871R will get you more air flow but this is not true. Neither of these turbos has any trouble fully supplying the 2.0T FSI at the limit of the factory MAP sensor (~22 PSI) out to 7500RPM. So let's fix boost at 22 PSI for this argument. Now think of air trying to flow through a hole. If you have 22 PSI of air driven by a pump going through a 1-inch hole with Pump A and then you have 22 PSI of water going through a 1-inch hole with Pump B...YOU HAVE THE SAME AMOUNT OF AIR FLOW. The hole in this argument is the engine (head, cylinders, etc.)

The only difference there may be is that Pump B may be more efficient at this pressure level and flow rate. Since this is air we are talking about and it is compressible and has a variable density, some would argue that there will be more air molecules available because it's a denser/cooler charge. This is true. But both turbos are heating up the air greatly so it's not like you have some significantly cooler air that doesn't require an intercooler. We are talking about a few percentabe points of efficiency, if that much. So, the argument for the 3076 is that it is more efficient at the top end and has a slightly greater amount of air molecules in the hot compressed air before the intercooler.

Great...right? Not when you consider that you lost over 1000 RPM of spool time and you have the increased inertia of spinning up this more massive turbo. Not when you consider that you are constantly downshifting to get any acceleration out of the car. Not when you consider that if you are using the factory map sensor on pump gas, you won't be making any more power (safely, that is). Now, if you are going way outside of the parameters I have mentioned (map sensor, pump gas, etc.), the 3076 will have its advantages at the top end but at the sacrifice of drivability in the low end.

Our 2871R kit hits full boost (~21 PSI) on pump gas at 3500RPM. I don't think this is conservative at all. I think this is driveable. Like I said, if you plan to do build a single purpose car or go above the factory map sensor limits, then a bigger turbo might be the answer. But if you are planning on running pump gas and keeping your factory map sensor intact, I think the 2871R is the perfect setup for the B7 and it's taller gearing.

Just my $0.02.

**Steps down from Soap Box**

[wezlo]

another question if I went with fordged pistons and rods could I up the boost in any way?

[4RingRook]

I believe so, but now you're into the $10K range...

[wezlo]

I know I know I can dream can't I

[Mike@APR]

hmmm you put up a good argument mike, I do like that I have a huge company behind the product. So if I bought the kit would I have to bring it to a Apr dealer to get it flashed ... It's a hour away how will I be able to drive there with a stage 2 flash not 3?

No longer on the iPhone...

I have two possible suggestions:

1. Get the kit installed at an APR distributor in your area
2. If you can't go with option 1 or if you plan to do the install yourselft... on the FSI engines, the best way to do this is to unplug the connector from the MAF sensor and drive the car slowly to your APR distributor. Make sure to stay out of boost. We have already done this with a few customers who have the Transverse Stage 3 kit.

[FLAudiMotion]

Wezlo:

The B7 Stage 3 kit from APR is not conservative at all for pump gas (93 octane). You must remember, these cars have a 10.3:1 compression and are less tolerant to just turning the boost up and advancing the timing. If we ran any more boost or timing on the production Stage 3 with 93 octane, we would get dangerous levels of knock that would not be good for your pistons (think melted metal). Also, with the tall gearing in the 6-speed B7, a 2871R is plenty big. That is unless you want your car to spool long after 4000 RPM. With a 3800lb car and tall gearing, the car will be very laggy.

If you want to build a dyno queen or single purpose drag racer, then I have no argument for you. But if you want to enjoy the car, I would not suggest a 3076 on pump gas. No offense to anyone offering that kit but I drive on the 2871R all day and have experimented with a 3071R on the same car and when running 93 octane and staying within the factory map sensor limits, the 2871R is a great setup. We are also currently tuning for 100 octane fuel so if you want big numbers, they are coming shortly.


**Stands on Soap Box**
Also, sorry for saying this but I want to break the misconseptions about turbos. Some might say that having a 3076 instead of a 2871R will get you more air flow and therefore more power but this is not true and is not being explained correctly. So many assumptions are made in this statment and so many details left out. Neither of these turbos has any trouble fully supplying the 2.0T FSI at the limit of the factory MAP sensor (~22 PSI) out to 7500RPM. So air flow is not a problem for either of these two turbos on this engine. So let's fix boost at 22 PSI for this argument and consider that neither of these turbos has any trouble meeting the air flow demands of the 2.0T FSI. Now think of air trying to flow through a hole. If you have 22 PSI of air driven by a pump going through a 1-inch hole with Pump A and then you have 22 PSI of air going through a 1-inch hole with Pump B...YOU HAVE THE SAME AMOUNT OF AIR FLOW. The hole in this argument is the engine (head, cylinders, etc.)

The only difference there may be is that Pump B may be more efficient at this pressure level and flow rate. Since this is air we are talking about and it is compressible and has a variable density, some would argue that there will be more air molecules available because it's a denser/cooler charge. This is true. But both turbos are heating up the air greatly so it's not like you have some significantly cooler air that doesn't require an intercooler. We are talking about a few percentabe points of efficiency, if that much. So, the argument for the 3076 is that it is more efficient at the top end and has a slightly greater amount of air molecules in the hot compressed air before the intercooler.

Great...right? Not when you consider that you lost over 1000 RPM of spool time and you have the increased inertia of spinning up this more massive turbo. Not when you consider that you are constantly downshifting to get any acceleration out of the car. Not when you consider that if you are using the factory map sensor on pump gas, you won't be making any more power (safely, that is). Now, if you are going way outside of the parameters I have mentioned (map sensor, pump gas, etc.), the 3076 will have its advantages at the top end but at the sacrifice of drivability in the low end.

Our 2871R kit hits full boost (~21 PSI) on pump gas at 3500RPM. I don't think this is conservative at all. I think this is driveable. Like I said, if you plan to do build a single purpose car or go above the factory map sensor limits, then a bigger turbo might be the answer. But if you are planning on running pump gas and keeping your factory map sensor intact, I think the 2871R is the perfect setup for the B7 and it's taller gearing.

Just my $0.02.

**Steps down from Soap Box**

Being a fellow mechanical engineer I can vouch for everything this man just laid down. Sometimes I get the feeling that Audi owners talk about big turbos like Honda owners talk about large/loud exhaust pipes.

[Mike@APR]

another question if I went with fordged pistons and rods could I up the boost in any way?

On pump gas, there is no way to up the boost. As I stated earlier, more boost will make the car knock on pump gas. In addition, if you did add more boost on pump gas, the car would retard the timing by so much (trying to prevent knock) that your timing would be very low and your exhaust gas temperatures would rise to dangerous levels as a result.

On race fuel (100 octane) and at the factory map sensor limit, I have front-wheel drive GTI's running 11.9 @ 121 mph in the quarter-mile with this turbo. This setup put down about 430whp to the front-wheels. So I don't think horsepower is a problem. At these power levels, upgraded connecting rods are needed but you can keep your factory pistons and compression ratio.

Do you still think you need to exceed the factory map sensor limit? To answer your question, yes it can be done but I don't think it's necessary. You can make pretty big power at the limit of the sensor.

[wezlo]

Drive on the highway out of boost that's not possible... Ahhh I'd rather do the install, hmm now I have to find out the price of install

[Mike@APR]

Drive on the highway out of boost that's not possible... Ahhh I'd rather do the install, hmm now I have to find out the price of install

Yes, you can drive on the highway out of boost. I can drive my Stage 3 B7 all day with 5 psi or less and it's quite comfortable and responsive. This setup has very useable torque anywhere over 2000 RPM. Especially if you row through the gears correctly, you can pretty much keep the intake manifold at atmospheric pressure or less and have a very streetable car. My wife is pregnant so I drive her around in the B7 like this all the time. Whenever I hit boost she gets nauseous and I get in trouble.

[Geoffafa]

On pump gas, there is no way to up the boost. As I stated earlier, more boost will make the car knock on pump gas. In addition, if you did add more boost on pump gas, the car would retard the timing by so much (trying to prevent knock) that your timing would be very low and your exhaust gas temperatures would rise to dangerous levels as a result.

On race fuel (100 octane) and at the factory map sensor limit, I have front-wheel drive GTI's running 11.9 @ 121 mph in the quarter-mile with this turbo. This setup put down about 430whp to the front-wheels. So I don't think horsepower is a problem. At these power levels, upgraded connecting rods are needed but you can keep your factory pistons and compression ratio.

Do you still think you need to exceed the factory map sensor limit? To answer your question, yes it can be done but I don't think it's necessary. You can make pretty big power at the limit of the sensor.

if its the one im thinking about, wasnt it an 11.71? no wait didnt he break 10's?

[Mike@APR]

Being a fellow mechanical engineer I can vouch for everything this man just laid down. Sometimes I get the feeling that Audi owners talk about big turbos like Honda owners talk about large/loud exhaust pipes.

Thanks for getting my back on this one.

I think all the talk about big turbos is pretty normal. Everyone has heard of some guy or another who made "big power" or some crazy quarter mile time with this huge turbo. Before you know it, the story takes on a life of it's own and people want that turbo. That is until they drive the car. It's a simple as this...these are not race cars. The turbo needs to be properly sized to keep some street drivability. I mean honestly, if the biggest turbo was the answer to everything, why would we have chosen a 2871R to bring to market?

We have chosen this turbo because we are trying to make good power but also a stisfying driving experience whether on the road or on a road course. In addition, there is more than enough head room to please the drag racers.

Also, selling a turbo that is too big looks something like this....

- APR announces Big Turbo kit using Garrett "Too Big Turbo" on 2.0T FSI A4
- Customers flock to "Too Big Turbo" setup and praise APR for going "big"
- Customer daydreams about said "Too Big Turbo" everyday waiting for the package to arrive from APR
- Customer receives package and installs kit at breakneck speed
- Customer takes first drive in car and realizes that spool doesn't happen until very late in the RPM band. However, the punch at the end keeps his spirits up. Plus he doesn't want to admit that he got what he asked for and doesn't like it.
- Customer continues to drive car everyday and gets passed by lesser cars at every stop light while waiting for turbo to spool.
- Resentment grows and customer now blames APR for poorly tuning his "Too Big Turbo". APR explains that you "can't escape physics and that we gave you what you asked for."
- Both APR and customer have big regrets

[FLAudiMotion]

Haha!! People have to realize most of the fun of driving these cars is there low RPM around town acceleration. sure the highway is fun, but smokin a mustang stop light to stop light is a blast!

[Mike@APR]

if its the one im thinking about, wasnt it an 11.71? no wait didnt he break 10's?

That was a different car. The car you are thinking of went 11.01 @ 131mph but he has a single purpose car with a custom setup. The kit originally started out as a production Stage 3 but the customer went custom and we provided the tuning as he works for one of our best distributors. It was sort a "push the limits" project. This car is making 605whp but it takes a lot to support this much power with the stock 10.3:1 compression. This is no longer much of street car in my opinion. In addition, the power isn't anywhere near 605whp if he was using pump gas. Talk about melting a piston... So for pump gas, you would gain lag but not much else.

[Mike@APR]

Honestly guys...I hope that what I am saying is more informative than anything else. I know that I work for APR and I have an interest in selling our kit. However, as the owner of a B7 that I drive every day, I also can use my experiences as a driver of "big turbo" 2.0T FSI and as an engineer within APR to let you know about what these turbos are like on these cars since you can't always experience them first hand. I truly believe that the taller gearing and heavy weight of the B7 chassis (especially the quattro cars) deserves a properly sized turbo such that the car does not feel like a dog all day off the line. I have been driving my B7 in a few different iterations since June of 2008 and I have been driving and developing big turbo 2.0T FSI's in general since April of 2007 and that is where this information is coming from.

[wezlo]

You know you really pitch a good product here, Your a pretty good saleman too.

[B7 Projectile]

You know you really pitch a good product here, Your a pretty good saleman too.

X2

Great information!! This cleared up some things..

Btw, any guess on what we might be looking at with a race gas file?

[rnp614]

Honestly guys...I hope that what I am saying is more informative than anything else. I know that I work for APR and I have an interest in selling our kit. However, as the owner of a B7 that I drive every day, I also can use my experiences as a driver of "big turbo" 2.0T FSI and as an engineer within APR to let you know about what these turbos are like on these cars since you can't always experience them first hand. I truly believe that the taller gearing and heavy weight of the B7 chassis (especially the quattro cars) deserves a properly sized turbo such that the car does not feel like a dog all day off the line. I have been driving my B7 in a few different iterations since June of 2008 and I have been driving and developing big turbo 2.0T FSI's in general since April of 2007 and that is where this information is coming from.

How do you feel about the K04 kit APR is about to put out? I'm sure you've got some time behind the wheel of one of those as well. Now I'm curious to hear your input.

[swoardrider]

How do you feel about the K04 kit APR is about to put out? I'm sure you've got some time behind the wheel of one of those as well. Now I'm curious to hear your input.

Me too. I'd like to hear your opinion between the 2 turbos. I desperately need to upgrade to more power for the road race track. I'm stuck behind higher horsepower cars that hold me up all day long in the turns because I don't have the power to pass them on straights unless they point-by and lift like crazy. Its pretty embarrassing when you can't even pass a spec Miata!

I'm torn between the k04 and 2871. I definitely want more across the entire rpm range, as this car could really use it. Will the 2871 make more or less power than the stock k03 say from 2000-3500 rpms?

[rnp614]

I bet it'd be about the same either way.

[Jim@STaSIS]

STaSIS MTF 2.0T Turbo Upgrade:
http://www.stasisengineering.com/turbo.php

The only offering on the market [that i know of] with a an ARB exemption order # [yes, that means CA smog legal] as well as a 1 year/15k mile warranty. If bought + installed at a STaSIS Signature Series Audi Dealership your factory 4 year / 50k mile warranty will be INTACT.

A review from the last track day our B7 did [which is the owner's daily] from that other audi forum: http://forums.audiworld.com/a4b7/msgs/110497.phtml

[Jim@STaSIS]

Forgot to mention our MTF Turbo kit is on sale through December. Free install if you're local or free exhaust if you're not:

http://www.stasisengineering.com/hol...olidaysale.htm

[wezlo]

So Still no one with a new kit out yet? whats going on? i need a BT kit something with more power then apr!

[JRMSLINEA4]

Honestly guys...I hope that what I am saying is more informative than anything else. I know that I work for APR and I have an interest in selling our kit. However, as the owner of a B7 that I drive every day, I also can use my experiences as a driver of "big turbo" 2.0T FSI and as an engineer within APR to let you know about what these turbos are like on these cars since you can't always experience them first hand. I truly believe that the taller gearing and heavy weight of the B7 chassis (especially the quattro cars) deserves a properly sized turbo such that the car does not feel like a dog all day off the line. I have been driving my B7 in a few different iterations since June of 2008 and I have been driving and developing big turbo 2.0T FSI's in general since April of 2007 and that is where this information is coming from.

Good point, people don't always think about how the cars weight playes into account.

[Zebman]

Good point, people don't always think about how the cars weight playes into account.

Which is why i'm working to make it lighter first.

[D.C. Designs]

^ details on what you dicthing sir :0)

[dougyfresh]

Good point, people don't always think about how the cars weight playes into account.

Which is why my car has the turbo that it does. Torque comes on strong and early and HP peaks shortly thereafter and holds out to redline. Its a hoot to drive on the street and just goes.

[Zebman]

^ details on what you dicthing sir :0)

Seats for starters. There's quite a few motors in them, and the necessary padding and shit for heating. Not to mention they are huge, and i'm not a very wide guy, average at best. So i'm ditching them for some Status seats, assuming they will ever get back to me about fitment. I'm predicting to drop ~100 or 150 optimistically.

I've already ditched the spare (HEAVY, like 65lbs. The stock split 5s are startling to pick up), and got a 11lb.battery vs. the ~40-50 stocker. I was thinking about a Lexan windshield, but i've heard more than enough horror stories of rear views falling off/not sticking to make me second guess that.
I'm hoping to have a CF hood down the line, colormatched. ~15 vs. 40 or so stock.

Also been thinking about taking the stock sub out.

I don't want a fast car in a line, it's not a good platform for that, but it IS a good platform for handling with some tweaks. I want to do all I can within reason to lighten it, get the STaSIS 40/60 differential, then have it corner balanced and have the damping turned up to be more aggressive.

EDIT: Oh yeah, can't forget my OZs. 16.7lbs each vs. what feels like 25-30 for each Split 5. And it's all reduced rotational mass too, woot!

[D.C. Designs]

wow sounds like a great plan