Serious: Why would someone build a 1.8t instead of a 2.7tt?

[Tumbler510]

I have been looking at amateur rallying, and thought a B5 S4 would make a good rally car. The more I looked into it, the more I saw preference for a 1.8t. And beyond that, I saw quite a lot of 1.8t parts to build blocks, and make big HP numbers (600+). As someone who was planning to STK a 6262 on my next B5 S4, and make 600-700 HP, this seems odd.

The only advantages I see in a B5 1.8t vs a B5 S4 are:

Initial Price
- The price is a B5 1.8t is lower than a B5 S4. Not by a ton, but they can be had for cheaper

Less parts/more empty engine bay
- 2 less cylinders means less forged pistons/rods/bearings/etc.
- Mounting the turbo on the top side makes it a hell of a lot easier to work on

So, I would like to get your feedback on this.

[ReggieNoble]

Bt 1.8t's are nice ( owned 3 of them ) but will never have the low end power of a 2.7t. In rally it's all about low end and maintaining speed. Also in my opinion a single turbo 2.7 would not be as near fun as having a solid k04 car.

Sent from my R1 HD using Audizine mobile app

[Audibot]

1.8t is also lighter than the 2.7t, so that's a factor as well. Lighter=faster, for a given power.

[chris86vw]

1.8t also simpler, even a STK on a 2.7t is a lot more complicated than the 1.8t. That makes it cheaper to run and there is less to go wrong.


Also check that engine build thread costs. For the costs of building just the engine some people are listing you can do the engine and the turbo setup on the 1.8t.

[tar]

Cheaper to build, easier to work on, lighter(very important), possibly more reliable but that's kinda iffy when talking both built motors big turbo

It really depends what kinda racing ur planning to do also and what ur budget is.

Starting cost for b5 a4 can be as low as 500 vs a few grand or more for a s4.

[Audibot]

less to go wrong

Sounds about right

[CELison]

There's also more of them out there.

[Ephry73]

Driving a stage 2 k04 1.8t B6 now and I can tell you the k03(stock turbos) with stage 2+ tune and open DP and custom exhaust just felt twice as powerful down low and the torque was constant on any gear. From being able to do 60mph in second without an issue to not having to down shift in sixth gear to pass anyone already going 80mph. Just no substitute for displacement and when the twin turbos are working and no leaks it’s a great thing. That said, I would love to see the vrT setup to compare.


Sent from my iPhone using Tapatalk

[ActiveMonkey]

I love the was a running 2.7T feels (i have 2) however there is damn near nothing i can't fix on the 1.8T over the course of a night. The repairs on the 1.8T are sooo much easier in every way. When i snapped my 1.8 taming best i threw a new head on it the next day and all was right as rain.

[chris86vw]

I love the was a running 2.7T feels (i have 2) however there is damn near nothing i can't fix on the 1.8T over the course of a night. The repairs on the 1.8T are sooo much easier in every way. When i snapped my 1.8 taming best i threw a new head on it the next day and all was right as rain.

HA I know exactly what you mean there. It was my 2.0T but 800 miles from home (luckily near my parents though) I cracked a spark plug on the dyno and destroyed my head. Grabbed a spare from a friend in the area and swapped it in my parents garage to head home the next day.

[MetalMan]

Simplicity, ease of maintenance, ease of performance upgrades, etc. as mentioned above.
I've had a 1.8T in 3 different A4s since 2010. My current B5 A4 has been pretty solid and quick: 277awhp + 309awtq on an older F21 + rods + E85, with all the other supporting mods. In my mind it's faster than a stage 1 B5 S4 on pump gas, possibly faster than a stage 2 S4 (but maybe not on E85). Also more nimble because of less weight.

Recently I picked up a B5 S4 Avant, and it's my first personal venture into the 2.7T. You still have access to stuff on the 2.7T, but have to allot way more time because of all the "layers" of parts to remove.

Also 2.7T has way more parts! Two banks means 2 of almost everything; that's double the VCGs to fail/leak, twice as many cams, substantially greater intake tract for leaks, etc. So higher cost and in some cases almost double the labor time when it comes to maintenance.

[aysix]

I enjoy building a 1.8T, and done a couple of them. It's so easy, less to go wrong, more room, etc. It's just fun, but not swap worthy into anything else IMO.

I love the was a running 2.7T feels (i have 2) however there is damn near nothing i can't fix on the 1.8T over the course of a night. The repairs on the 1.8T are sooo much easier in every way. When i snapped my 1.8 taming best i threw a new head on it the next day and all was right as rain.

Yep, same. I bought my current b6 with a bad head on craigslist for almost nothing and went to the junkyard and had it running the same day.

[Tumbler510]

So based on all of the people in here who have built a 1.8t to high power levels, would that be the way to go instead of a built 2.7tt B5 S4 with a STk+6262 turbo+E85?

Seems like you can make nearly the same power level on the 1.8t, and its a bit more unique IMO.

[chris86vw]

I enjoy building a 1.8T, and done a couple of them. It's so easy, less to go wrong, more room, etc. It's just fun, but not swap worthy into anything else IMO.

Sure it is, even a crusty high mileage bone stock 150hp version is worthy of a swap into say a rabbit or hell all the way up to a mk3 golf/jetta. Fined a tuned totaled parts can and you can double your power for under a grand in a weekend.. That is very worth it.

[aysix]

So based on all of the people in here who have built a 1.8t to high power levels, would that be the way to go instead of a built 2.7tt B5 S4 with a STk+6262 turbo+E85?

Seems like you can make nearly the same power level on the 1.8t, and its a bit more unique IMO.

Aint.

1.8t's will make the power, but the 2.7 will be spooled up and gone by then.

[ReggieNoble]

Aint.

1.8t's will make the power, but the 2.7 will be spooled up and gone by then.

Agreed...I guess non of these guys ever watched group B. The v6 turbos dominated. They were so fast and dangerous that they did away with all the v6 cars. Not saying there wasn't a few 4 and 5 cylinders in group B. Now all you can race in group A is up to a 1.6 with no more than 380bhp. It seems wrc is turning into formula 1. What a shame.

Sent from my R1 HD using Audizine mobile app

[S4James]

To answer the question posed by the original subject:

A: Because you are poor.

[aysix]

To answer the question posed by the original subject:

A: Because you are poor.

lmao

[Tumbler510]

Agreed...I guess non of these guys ever watched group B. The v6 turbos dominated. They were so fast and dangerous that they did away with all the v6 cars. Not saying there wasn't a few 4 and 5 cylinders in group B. Now all you can race in group A is up to a 1.6 with no more than 380bhp. It seems wrc is turning into formula 1. What a shame.

Sent from my R1 HD using Audizine mobile app

That's actually what started this entire thinking in my head. Rewatching more Group B documentarys and race footage.
Effing ridiculous even after all this time!

[Perth_RS4]

I think the 1.8t would handle better when modified to the max because of less weight in front of the front axel compared to the S4's heavy V6. In rally, turning is more important than out right power.

[ActiveMonkey]

1.8 Engine w/ turbos is ~350lbs
2.7 Engine w/ turbos is ~420lbs

Really not much weight savings if you ask me. Especially when you're going to have to throw one hell of a large turbo on the 1.8 to match a 2.7 with pjK04s. just my $00.02

[ReggieNoble]

I think the 1.8t would handle better when modified to the max because of less weight in front of the front axel compared to the S4's heavy V6. In rally, turning is more important than out right power.

You'd be surprised how much a lighter car will slide around, the weight in some cases will help. Especially how the grooves will form on the corners, from the other cars. At that point it becomes having the HP wins

Sent from my R1 HD using Audizine mobile app

[ReggieNoble]

That's actually what started this entire thinking in my head. Rewatching more Group B documentarys and race footage.
Effing ridiculous even after all this time!

Yeah the footage is amazing, and the drivers and co-drivers are even more amazing. Watching in-car video always blows my mind.

Sent from my R1 HD using Audizine mobile app

[ReggieNoble]

I think the biggest killer on the 2.7 would be the heatsoak.

Sent from my R1 HD using Audizine mobile app

[ReggieNoble]

Plus I noticed the 2.7 is way more consistent day to day then my 1.8t's where. I swear one day my 1.8 would feel like 500hp then the next day it would feel like 50hp. It all depended on how it felt that day lol

Sent from my R1 HD using Audizine mobile app

[Ephry73]

On a side note, today it has been icy in NY and I missed the weight of the motor in the B6. If you want competitive driving then torque is where it’s at. Hands down. Torque = acceleration.


Sent from my iPhone using Tapatalk

[james 408]

lighter & cheaper as stated. I would consider power targets and turbo lag. Even if you can get the 1.8 as high HP it's just not going to be as fast due to lag (absent anti-lag); but the weight will offset that depending on the track. For a rally car, absent a bunch of high-speed courses, I wouldn't really be focused on peak power so much, so if you're looking to make 300 horse, the 1.8 might be a better choice when you piece in all the different factors.

I'd also consider things like differentials, starting weight, etc. Like most of what you're paying for in the audi are going to be stripped out anyway, and replacement costs are generally higher. Buying a piece of crap subaru might be a cheaper route if you wanna stick in 4wd classes (granted I'm not the biggest suby fan cause I've had/seen reliability issues). Similar thoughts:
talon/eclipse
evo/galant
E30 IX

[S4James]

every 1.8t contender in my town has gone down to my lightly modded 2.7T :)

[redline380]

If you want competitive driving then torque is where it’s at. Hands down. Torque = acceleration.

Lots of good answers here, this is the best.

I have both in my garage, a BT 1.8t B5 and a 2.7tt. The 1.8 is a ton of fun, it pulls great once spooled, and makes all the sweet riceboi noises. But then I jump in the 2.7, keep it in 3rd around a tight corner, and I can hardly tell it should be in second. Passing on the highway does not require downshifts. In my 1.8t, I'm constantly searching for gears to find the right rev range to make power.

They are just two different cars. Why can't we have both?

[Tumbler510]

They are just two different cars. Why can't we have both?

A: Because you are poor.

:)

[LJS]

............. If you want competitive driving then torque is where it’s at. Hands down. Torque = acceleration.

OK- Will a Cummings Diesel slip into a B5 without to much trouble....
Only kidding!

[chris86vw]

OK- Will a Cummings Diesel slip into a B5 without to much trouble....
Only kidding!

Ha was going to say I once drove a cummins equipped 3500 over 200 miles without shifting out of 6th gear, as slow as about 35 and as fast as about 80.

4bt might fit lenghtwise, I can measure tomorrow..

But they are a little tall :)

[Ephry73]

OK- Will a Cummings Diesel slip into a B5 without to much trouble....
Only kidding!

Well another option is a diesel TDI motor. I had a golf Tdi MKIV stage 2 and that thing was a beast!! Bobs of torque from 1,800 rpm all the way to 4,000+. Never had it dyno’ed but definitely had to be in the 240ft/lb+ range. That was a mild tune and open down pipe to magnaflow straight through muffler with stock turbo and nozzles. There’s good tunes and hardware out there to put you in the torque range you need and higher horsepower albeit in a small diesel. But you will need to change your fueling etc. just a thought. A nice diesel Tdi Quattro A4 with a good tune would be a beast.

E


Sent from my iPhone using Tapatalk

[VR6Bomber]

I know that this has been touched on already;

You've seen teams pulling EJ's out of subaru's in between stages, that's not going to happen with a 2.7t without significant resources.
Rally racing a b5s4 would be a very expensive proposition.

I would vote 1.8T for any competition motorsport. easy to come by, easier to fix, cheaper all around etc


Honestly, if this is your first try at rally, you should probably build your skills with a N/A 2wd vehicle waaay waay waay before jumping into turbo awd. Turbo awd will put you against veteran teams and factory backed team cars only put out about 300-400 hp, these guys are pros.

Mk2 Golf is the 'go to' beginner rally car, Neons and regular ford focus too
2.5 impreza if you want to jump right into the awd class

GL