Daily driver GT, would you rather stock bore and built heads or stock heads and 3.0l?

[jibberjive]

Just getting some opinions, if you were building a GT setup where you'd be daily driving so spool, reliability (oil consumption), and gas mileage were all concerns, assuming the same price, would you rather have a 3.0l bottom end and run stock big port heads about 7200-7300 RPMs max (though daily driving I'm sure I'd rarely break 6k), or keep the stock pistons and build the 2.8 heads with valvetrain that can rev up to 8k?

I'll do more research on 3.0l later, but what are my piston options? I know VAST has their setup, and weren't people going with some Diamond pistons too? Others off the top of your head?

From my perspective so far for pro's/cons of each:

3.0l/Stock heads:
Pros--
-Even faster spool for DD
-More power off spool
-Don't need to rev it out to get close to maxing turbo

Cons--
-Worse gas mileage
-Oil consumption/reliability concerns
-Can't rev it out if I want (which I probably wouldn't want to anyways)
-Stock head reliability?

Built 2.8 heads/Stock bore:
Pros--
-Stock-like reliability/oil consumption and better than stock gas mileage
-Can rev out if desired
-Head reliability not questioned

Cons--
-More lag around town and less power off boost


Opinions and logic?

[GURUMAN]

Copied from my post

Good shot because a lot of mistakes are being done in all the high HP wannabe builds.

Wanting to go all out is not always the right answer !

[jibberjive]

Copied from my post

Good shot because a lot of mistakes are being done in all the high HP wannabe builds.

Wanting to go all out is not always the right answer !

Yeah, like I said the idea popped into my head when a local dude about a week ago said he's got 3 3.0l cranks. With the added stroke, you don't really want to be wrapping the engine out too high anyways, so the built heads on the 3.0l build would just be done more for reliability (assuming they're done right, which they aren't always.) And of course the supertech valves will help flow a little better, but with a 3.0l and big port heads, I'm not too worried about that difference.

Any input from Ringlord about Jason's comments on the weaker seat pressure of the stock 2.8 valves? Just thinking about it logically, I don't think it'd be an issue, but I've been wrong before.

Are the 2.8 valvesprings/retainers the same as the 2.7?

[bigern45]

i think that is the biggest thing that i noted when i went from a chipped stage 2 car to stage 3 with the RS6 turbos hitting full boost right at 3900-4100... i initially missed that low end grunt, you know, the grunt where your exhaust isnt even making noise, yet you are pinned to your seat. and going 3.0 is tempting, but im not sure if the cost and end result would be worth it. ive driven a honda S2000 before, i had to install an engine on one. as much as i missed the low end grunt that DOESNT exist in that car, i loved revving it from 6000-9000. so i know if i ever did a build more than what i have, i wouldnt bore or stroke the car. maybe 2.8, but thats just playing with inside parts, not removing any of this beautiful iron that makes this engine so strong, which in turn, could do away with a lot of reliability issues. i dont have any technical data for you, im just giving my opinion on your build. id love to have my 2.7 built, and even though i run outta power by going to my 7300 limit, i do it everytime i can. id love to rev to 8200 in this car, and if i were to do a build, id go built 2.8 heads/cams, rods internally (only, i guess you have to do pistons to get that displacement) then id go RS4 intake mani, port and polish everything. then comes turbo choice. the 770's can be pushed quite a bit, and their spool is tempting compared to some gt setups. so.. idk.. thats just my opinion, mang..

and remember, ive only been around for 2-3 years, so me with tech data isnt happening, although i do post up drag vids and results whenever i can. .. hell mike, you're the one that got me into all of this shit in the first place. when you sold me your crap, i wish you woulda told me " it isnt going to end here".. lol.. at least i would be prepared..

[wdbdy2000s4]

Rev the piss out of a 2.7.

[NogaroAvant]

I am going 3.0L with built heads. I like the fact that the car will spool quickly, have more low end grunt and still have lots of volume and flow up top combined with the worked 2.8L heads. I was never one to rev out motors ( I come from a long line of all motor VR's and VR turbo's) but I decided to build the heads on my S4 build for flow (that is where the limiting factors are in these cars) and insurance that if I do rev it out for a few 1/4 mi runs, TX mi runs or races I'd feel more comfortable doing so. I went through the 3.0L build with my machine shop and discussed the components and specifications with them and they feel that oil consumption will not be an issue.

Going 3.0L is definitely not a necessity. AMD and EPL have proved that with their numerous TiAL cars running in the 600whp range. Honestly they have proved that stock pistons and headbolts might be the way to go. On thing you do see them doing is 2.8L heads with ported bowls and supporting valvetrain upgrades...

If I were building a daily GT car, I would go with stock bore/stock pistons and build the 2.8L heads with gasket matched and ported bowls. Power is all in the heads and stroke. Since you won't be stroking the motor, the head work will be key!

[GURUMAN]

The most inportant par in all these aspects is the 1-2 shift

if you guys dont want to be humiliated by a stage 2 car, calculations are the key...

[sfored]

my turbos are larger than any GT Kit out there ... if you are racing ... 1-2 is NO issue if you are revving it high/hard.
IF it is a Daily Driver ... the above sentence is NOT a DD car...

[wdbdy2000s4]

The most inportant par in all these aspects is the 1-2 shift

if you guys dont want to be humiliated by a stage 2 car, calculations are the key...

I think the 2860s will be fine if he's revving to 8400. He shouldn't fall out of boost on the 1-2.

[Trigger Happy]

Question, and it may be an ignorant one, but can you just put a 3.0l crank in without changing the bore? That would put displacement at 2.9 if I'm correct.

IMHO your decision rests on how reliable a 3.0l is going to be for daily driving. I don't think the fuel mileage would differ that much from 2.7-3, and changing your driving style alittle should make up that difference. Plus if you ever wanted to go all out you could build the heads much easier than swapping the crank out to go 3.0l.

[GaroBlu]

my vote is also for built heads. If you are really concerned about gas mileage the 2.7 is the way to go. You will still have the power up top for when you want it. Besides, even with slower spool, you will be more than able to pass cars and get on the freeway quickly. I know having more power down low is good for a daily driver, but keeping stock displacement is the clear winner here.

[sfored]

It'd be interesting to hear from the GT guys who had the S4 as their daily drivers; don't get me wrong - once spooled ... it is a different experience but IMO not a "fun" daily driver

[TweetsS4Estate]

I still have yet to drive one lol takes forever to do it right sometimes! I'll tell you a 3.0L 2560 car would spool nice I've.

[imola]

I'd rather have the 3.0 bore than high revving only.. I'm a fan of low end grunt.. Personally, I went with 3.0 (bored) and built 2.8 heads w/770s.. But thats as much as I can say since I'm still waiting on dp's and have yet to drive the thing and post on how much fun it is/isnt.

[TweetsS4Estate]

The most inportant par in all these aspects is the 1-2 shift

if you guys dont want to be humiliated by a stage 2 car, calculations are the key...

Thats why I changed my 1st and 2nd gear ratio. lengthen the gear, create more load, have time to make power in that gear. With a stand a lone it is a new ball game though.

[blackbenzz]

The most inportant par in all these aspects is the 1-2 shift

if you guys dont want to be humiliated by a stage 2 car, calculations are the key...

Ding ding ding!!!

[GURUMAN]

Ding ding ding!!!

I did win 98 % of my street racing drag events races just by hitting second gear and remain in my boost and torque happy curve. (2% was from driver error missing the gear) LOL

Once it's dialed in, the rest is a pure raw horsepower game that become too costly for the majority...

I had the chance to enjoy both 2.8L on 28rs and 3.0L on 28 rs

Peak hosepower was 576 WHP compared to 649 WHP

Times were 11.49 @ 128MPH compared to 10.51 @ 140 MPH


The 3.0L was a lot more forgiving on the track because of lowend torque, and 95% of the time I was ok in second.

On a stock 6 speed tranny with 225/45R17 tires if you revv to 7500 to redline, when you shift second, you will get down to 4050 rpm (look at your HP and torque curve here)

If you bump your revv limiter to 8000rpm, you will en up at 4320 RPM

At 8300, it lands you at 4482 rpm

And 8500 rev limiter will stuff you at 4590 RPM
ON MY POWER CURVE



SEE ON SHERIF'S can advance 3.0L with 28RS (look torque at 4000 rpm)

[sfored]

I think you are off on your calcs of where you will land between gears.

I did win 98 % of my street racing drag events races just by hitting second gear and remain in my boost and torque happy curve. (2% was from driver error missing the gear) LOL

Once it's dialed in, the rest is a pure raw horsepower game that become too costly for the majority...

I had the chance to enjoy both 2.8L on 28rs and 3.0L on 28 rs

Peak hosepower was 576 WHP compared to 649 WHP

Times were 11.49 @ 128MPH compared to 10.51 @ 140 MPH


The 3.0L was a lot more forgiving on the track because of lowend torque, and 95% of the time I was ok in second.

On a stock 6 speed tranny with 225/45R17 tires if you revv to 7500 to redline, when you shift second, you will get down to 4050 rpm (look at your HP and torque curve here)

If you bump your revv limiter to 8000rpm, you will en up at 4320 RPM

At 8300, it lands you at 4482 rpm

And 8500 rev limiter will stuff you at 4590 RPM

SEE ON SHERIF'S can advance 3.0L with 28RS (look torque at 4000 rpm)

[buddysnack]

What do 2.8 heads cost (if you are already going to be rebuilding your engine)?

[julex]

if you don't want to screw around with boring a block, there is always an option of 3.0L crank and 81mm pistons (stock bore) or 81.5 (will fit with slight honing) made for 3.0l crank stroke. This lands you with 2.9L displacement and factory strong head, none of that 5mm of meat left on 3.0L block.

But.... is around 1.2k extra worth 200cc of displacement? most likely seeing that people spend that much on crap yielding far less HPs/TQ.

[julex]

What do 2.8 heads cost (if you are already going to be rebuilding your engine)?

Anywhere from 150-400 depending if you're ok with bent valves/highh mileage and general condition of heads.

[TweetsS4Estate]

why don't you just change 1st, and 2nd gear and build the heads... lol

[TweetsS4Estate]

I have a set of 2.8 heads they just don't have 2.8 cams.

[sfored]

why don't you just change 1st, and 2nd gear and build the heads... lol

i have been preaching this for a long time (Esp to EvilEvo whom just spent some $$ on his tranny) but I don't think I heard any reasonable prices on this...
I think if we can get the end of 1st 45-50 and 2nd around 90ish mph ... BAM

can we get some info on yours or pm or ?

[TweetsS4Estate]

The trans goes together this week.. I'm waiting on a clutch but I can post a video of it revving out if you'd like to see it. I'd have to ask scott again what my ratios are.

[jibberjive]

Here goes a killer multi-quote

and going 3.0 is tempting, but im not sure if the cost and end result would be worth it.

The cost would be approx the same as building the heads. If I stay 2.7 I'm already paying for rings, crank bearings, cylinder hone, and balancing the rotating assembly anyways, so the only cost differential to go 3.0l is to find a 3.0l crank and buy pistons. So consider it about the same cost as building the heads in my case.

so i know if i ever did a build more than what i have, i wouldnt bore or stroke the car. maybe 2.8, but thats just playing with inside parts, not removing any of this beautiful iron that makes this engine so strong, which in turn, could do away with a lot of reliability issues.

I'm personally not worried about the strength of block from boring it out. Rather the reliability factor I'm worried about has to do with the 3.0l pistons and rings. I've heard of some motors that burn an appreciable amount of oil. I'd hate to burn oil, lose compression, or have to rebuild anytime in the near future. I'm building it so that it doesn't need another rebuild for 100k+ mi of daily driving, like the stock engine.

.. hell mike, you're the one that got me into all of this shit in the first place. when you sold me your crap, i wish you woulda told me " it isnt going to end here".. lol.. at least i would be prepared..

Well I did expect you to be satisfied running the RS6's for a little more than a year ha, but I think you got the better deal of that considering you've actually been driving your car for the past year and a half. I'm just hoping for myself that it does end here as far as B5 GT builds are concerned lol.

Going 3.0L is definitely not a necessity. AMD and EPL have proved that with their numerous TiAL cars running in the 600whp range. Honestly they have proved that stock pistons and headbolts might be the way to go. On thing you do see them doing is 2.8L heads with ported bowls and supporting valvetrain upgrades...

True. WMS' red car was a 2.8l w/ worked heads too. Def something to think about.

If I were building a daily GT car, I would go with stock bore/stock pistons and build the 2.8L heads with gasket matched and ported bowls. Power is all in the heads and stroke. Since you won't be stroking the motor, the head work will be key!

I won't be porting the heads much, rather just a simple cleanup, valvejob, install of all of the new hardware, but they will be 2.8l heads no matter what.

The most inportant par in all these aspects is the 1-2 shift

if you guys dont want to be humiliated by a stage 2 car, calculations are the key...

I honestly don't care if other cars beat me. I'm not necessarily building this car around racing. I chose the hardware based on daily driving and road course racing aspects. I'm hoping, of course, that along with that it'll beat lesser cars, dyno decent and do a decent 1/4mi (and I'll film them, win or lose, good/bad), but those aren't driving priorities of the build like the others are.

Or if you're just talking about racing techniques and not hardware selection, then I agree, calculation and execution is the key. That's what separates from Evilempire and Marc from most of the other KO4 cars for example; they know what they're doing, can drive well (shift fast, incredible reaction time on the roll or launch), and know how to stack up the advantages that they can control on their side (tweak, race gas, drive alone, weight reduction (in Marc's case), no exhaust (again in Marc's case), etc.) So much is in execution, and it can make equal cars appear drastically different. That's definitely a big part of what made Evilempire and Marc S4 superstars.

I think the 2860s will be fine if he's revving to 8400. He shouldn't fall out of boost on the 1-2.

Yeah, I prob should've put that in my first post. I'm running 2860's with smaller housings. I choose these turbos so that they would spool decent on the 2.7. These should spool between 2554's and 2560's as is on the 2.7l. On a 3.0l, these will literally spool like KO4's.

Question, and it may be an ignorant one, but can you just put a 3.0l crank in without changing the bore? That would put displacement at 2.9 if I'm correct.

I've always heard that you can't because of the angle the new crank puts the rods in relation to the piston. They hit the skirts or something, and that's why the 3.0l specific pistons have shorter skirts. Someone correct me if I'm wrong.

IMHO your decision rests on how reliable a 3.0l is going to be for daily driving. I don't think the fuel mileage would differ that much from 2.7-3, and changing your driving style alittle should make up that difference.

To be honest, fuel consumption is quite a ways back in priority compared to reliability and daily drivability. It is still a factor (above, for example, peak horsepower), but not near as important as reliability. Though I bet the mpg difference could possibly be kinda drastic, cause I've heard of laggy big turbo S4's getting like 24 mpg, and I bet a 3.0 will never get above 20 combined no matter how I drive it.

Plus if you ever wanted to go all out you could build the heads much easier than swapping the crank out to go 3.0l.

Very true, and actually something I was definitely thinking about. Say I go 3.0l with the stock heads for a while and later I decide I really would rather be able to rev a little higher. I can pull the heads (maybe even without pulling the motor if I want to get crazy), and the only one-time hardware I'd really have to replace are $70 worth of headgaskets and the intake/exhaust mani gaskets. Though, on the flip-side, if I went 2.7 and built the heads, I don't think I'd ever have the inkling to go back and make it 3.0, so that part's not really a factor.

my vote is also for built heads. If you are really concerned about gas mileage the 2.7 is the way to go. You will still have the power up top for when you want it. Besides, even with slower spool, you will be more than able to pass cars and get on the freeway quickly. I know having more power down low is good for a daily driver, but keeping stock displacement is the clear winner here.

As I said above, gas mileage is important, but not so important And it doesn't make more power down in the lower range because it is more powerful when it's off boost, but it adds even more power down low because it'll shift my powerband to the left 400 RPM's (or whatever), so these turbos literally will spool like KO4's. Decisions decisions, it's a tough call!

It'd be interesting to hear from the GT guys who had the S4 as their daily drivers; don't get me wrong - once spooled ... it is a different experience but IMO not a "fun" daily driver

Like I said elsewhere, I can't think of one person (except for maybe Dom, who only cared about the drag strip) who went GT28rs or bigger who hasn't said that having them spool a little sooner would be nice. My turbos are nowhere near the size of Adam's (Evilevo) 2871's though.

I'd rather have the 3.0 bore than high revving only.. I'm a fan of low end grunt.. Personally, I went with 3.0 (bored) and built 2.8 heads w/770s.. But thats as much as I can say since I'm still waiting on dp's and have yet to drive the thing and post on how much fun it is/isnt.

I still have yet to drive one lol takes forever to do it right sometimes! I'll tell you a 3.0L 2560 car would spool nice I've.

Both of you, keep us updated on it! Does it burn oil, how much increased low end, etc, and, as gay as it sounds, gas mileage lol.

I had the chance to enjoy both 2.8L on 28rs and 3.0L on 28 rs

Peak hosepower was 576 WHP compared to 649 WHP

Was this on the same dyno, same exact hardware (other than the 3.0l stuff), and same amount of fine tuning on standalone? I don't remember.

On a stock 6 speed tranny with 225/45R17 tires if you revv to 7500 to redline, when you shift second, you will get down to 4050 rpm

I didn't double check your math, but if that's true, I'm fine with that. With a 3.0l my turbos should already see some boost by 4000 RPM, if not very shortly thereafter. And that's just first to second, right? Like I said, I don't care as much about the dragstrip and racing from a dig, but care more about where I'll be driving 90% of the time (which isn't wrapping it out to 7500 from a stop through 1st and 2nd gear.)

What do 2.8 heads cost (if you are already going to be rebuilding your engine)?

Going from nothing to strapping built 2.8 heads on your car, around $3k if you're paying retail.
-$350-650 for the stock heads (not including shipping, they're 100lbs)
~$600 for standard valve job from a quality place
~$852 for valves
~$745 for ti springs/retainers

= ~$2550-2850 before shipping or tax

if you don't want to screw around with boring a block, there is always an option of 3.0L crank and 81mm pistons (stock bore) or 81.5 (will fit with slight honing) made for 3.0l crank stroke. This lands you with 2.9L displacement and factory strong head, none of that 5mm of meat left on 3.0L block.

But.... is around 1.2k extra worth 200cc of displacement? most likely seeing that people spend that much on crap yielding far less HPs/TQ.

I don't mind boring the block, and I'll have to hone either way. So you're saying stock-bore aftermarket pistons, not using the actual stock pistons, right? And I cringe at thinking of spending $1200 for 6 pistons, so if that's what it's really going to cost me in the end for just the pistons, I probably won't do it. However, if I do buy new pistons, then I'll be saving $250 in rings that I'd be buying for the stock pistons, plus prob $60 of cleaning for the stock pistons, and I'd already be doing the $250 balance and $200 of other hone/machine work anyways, so it could make sense to go 3.0l over stock if I get convinced that they're reliable enough and if I can find them cheap enough.

So I know there were a few people on the forums (here and QW) that run, or had, a 3.0l. Guru, NogaroAvant is going to, Tweets4?, bryzf1 is in his Allroad, Imola will soon...but I know there's more. Can anyone remember off the top of their head?

[bryzf1]

Oh man it's like the good 'ol days again w/ your monster posts! lol

The reason that I decided to go 3.0L was for the simple fact of having more power when out of boost for a nice daily driver and I have no desire to rev the piss out of it, and gas mileage for me wasn't an issue. I decided to also do built 2.8 heads w/ 2.8 cams as well as pistons b/c I got a good deal from Reid/Tweets on a set. My car has been in the shop for nearly a year b/c of delays w/ the machine shop and other misc BS, but i'll be sure to update when i'm up and running which should be very soon.

[jibberjive]

Oh man it's like the good 'ol days again w/ your monster posts! lol

The reason that I decided to go 3.0L was for the simple fact of having more power when out of boost for a nice daily driver and I have no desire to rev the piss out of it, and gas mileage for me wasn't an issue. I decided to also do built 2.8 heads w/ 2.8 cams as well as pistons b/c I got a good deal from Reid/Tweets on a set. My car has been in the shop for nearly a year b/c of delays w/ the machine shop and other misc BS, but i'll be sure to update when i'm up and running which should be very soon.

Lol Yeah, I tend to get a little crazy when I actually care about replying ha.

Did your car run previously with the 3.0, or has it been down a year for that?

[jibberjive]

Oh yeah, and spoolingGT is running 3.0l on his RS6's, right? I don't know if I'd trust what he has to say about them anyways though. Hey Adam, why don't you make another name and post your experience in here real quick before you get banned again.

[bryzf1]

Lol Yeah, I tend to get a little crazy when I actually care about replying ha.

Did your car run previously with the 3.0, or has it been down a year for that?

It's been down a year for that unfortunately. The machine shop sat on the motor for over 5 mos before they actually touched it. Although I did finally get a chance to crank it up a few weeks ago.

[bigern45]

dom does have some good reasoning. 1 second in the quarter improvement is no joke. but is that what you are looking for?? mike?? theoretically, if i get my clutch in and do the strip with my stock block RS6's.. then i could run 11.7... remember, i ran 11.9 with a slipping pp/clutch setup. if dom ran 11.5 on his stock block with rods (2.7), and i can run close. .. . with a new clutch? then who wins??? on the open street to 150, he would eat me alive, with the 2.7 gt setup he ran.. my point was period, id love to have a dd that would lag a slight bit, but then have a pull from 4500-8000 that would be insane.. i dont know if i could justify the work involved with going 3.0 , and then how often youd have to wonder if stuff is breaking ?? oil leaking?? and if you build the heads from a 2.8?? and no issues?? i mean there are some that have failed im sure.. , but i havent heard about them with this head/block setup, but i have heard about many 3.0's leaking oil, not lasting.. .. hrm. i mean, we are talking about the B5 S4..
by all means, if you can get someone to build the 3.0 for you, would be nice, but at that point, you are kinda tinkering with whether or not to go VR6 build.. thats just me..

[TweetsS4Estate]

Oh yeah, and spoolingGT is running 3.0l on his RS6's, right? I don't know if I'd trust what he has to say about them anyways though. Hey Adam, why don't you make another name and post your experience in here real quick before you get banned again.

I have logged and driven adams car. It never ran right though. I think it was a head problem and it is being worked on. That car burns no oil though. my 3.0L build, my first one did burn a little bit of oil, yet had no skirt wear which suggests that it is not a rod/stroke ratio problem but a machinist problem as well as having the right piston for the 3.0L setup. I think that the piston design has come a long ways since my build though. The biggest problem IMO was that there was not enough material between the top of the piston and the first compression ring, I have new pistons now from diamond and they look gorgeous. But as Guru found you can build a 3.0L right with out it burning anything but delicious fuel. Adams car boosts really fast with the 3.0L and RS6 hybrids, it comes in just as soon or sooner as my K04 car does.. with it running like shit I think I saw 3.1s out of the car on 20psi, I think it has low 2's written all over it when we can get a solid tune in it with it running well. I think I have some logs of it here with an MBC. I'll ask adam if he is cool with me posting it. BTW my car got 28mpg from grand rapids to minneapolis with a 3.0L 2.8 cams build 2.7 heads and rs6 hybrids. True story I have reciepts lol.

[megafreakindeth]

toyota did studies on stroke vs bore to obtain displacement and they found that undersquare(larger stroke than bore) produces more mpg. This can be verified in the field because square or oversquare motors tend to produce less epa mileage stats. Just food for thought though.

As for going to 3.0 it will necessitate more headflow. the 2.7 heads are already at a minimum size to enhance throttle response. Upping the displacement on stock heads will shift the powerband down and up the torque. This isnt a problem with big turbos(a more likely cause for the lower mpg of 3.0 cars) since their power comes up top. The recent tuning developments seem to be fine without upping the displacement. While it wont be best for getting that huge hp number to brag about, you may be best off using a 3.0 bottom end, ported 2.7 heads, and 2.8 cams. The smaller 2.7 port size will make it more diveable as a dd by enhancing low end throttle response at the sacrifice of some top end power numbers. On the 2.7 cranks side, a smaller stroke is more stable at higher rpms. Eg. less bearing strain, crank strain. This is moot if the crank is forged but i dont know if they are or not.

as for revving to 8k, hydraulic lifters float at 7200 about so anything above that can cause damage or strain at the wrong time. Again this isnt an issue for huge dyno numbers as much as it is for a motor youd want 150,000 miles out of. If you want DD reliability id rely more on the turbos for power than the engine. in my book timing and compression(static) are far more wear inducing than boost assuming you have adequate intercooling and tuning. GT turbos with just the con rods upgraded should be sufficient to make a good long term reliable car as well as just about guarantee youre faster than everyone else on the road.

[jibberjive]

It's been down a year for that unfortunately. The machine shop sat on the motor for over 5 mos before they actually touched it. Although I did finally get a chance to crank it up a few weeks ago.

Nice buddy! I bet you're jonesing to get that thing going. You're paying someone to do the work and it's still taking that long, I'd not be the most happy. I've got no one but myself to blame since about last Oct.

if dom ran 11.5 on his stock block with rods (2.7), and i can run close. .. . with a new clutch? then who wins??? on the open street to 150, he would eat me alive, with the 2.7 gt setup he ran.. my point was period, id love to have a dd that would lag a slight bit, but then have a pull from 4500-8000 that would be insane.. i dont know if i could justify the work involved with going 3.0 , and then how often youd have to wonder if stuff is breaking ?? oil leaking?? and if you build the heads from a 2.8?? and no issues?? i mean there are some that have failed im sure.. , but i havent heard about them with this head/block setup, but i have heard about many 3.0's leaking oil, not lasting.. .. hrm. i mean, we are talking about the B5 S4..
by all means, if you can get someone to build the 3.0 for you, would be nice, but at that point, you are kinda tinkering with whether or not to go VR6 build.. thats just me..

Wow, a couple of tangents going on there Well, Dom hasn't replied yet about if the exact hardware/level of tuning was done to both setups. IIRC, he was on ME7 with his 2.8 setup and went standalone with his 3.0l build and had plenty of time to tweak the car and improve his skills at the track with all of the runs he did with his 3.0l. So I'm not sure if you can say he went from 2.8 to 3.0 and bam, 1 sec faster in the quarter. And as far as power figures, were both of his dyno runs on the same dyno? I just don't remember.

As far as justifying work to go 3.0l, it'd actually be less work for me to go 3.0 and leave the heads stock than it would be to build the 2.8 heads. I've already got the engine completely disassembled and will be balancing the rotating assembly and honing the cylinders either way. All I'd have to do to go 3.0l instead is to plop the 3.0l crank in there instead and have them bore it rather than just hone. In order to build the heads I have to get all of the head hardware again and pay $600 for a valvejob. Either way, I've already got the hardware for a GT and absolutely zero desire to do a VR6 swap even if I didn't, so that a complete non-factor ha. If I want a VR6 I'll either go buy a VW or swap it into a car that is more straight forward.

I have logged and driven adams car. It never ran right though. I think it was a head problem and it is being worked on. That car burns no oil though. my 3.0L build, my first one did burn a little bit of oil, yet had no skirt wear which suggests that it is not a rod/stroke ratio problem but a machinist problem as well as having the right piston for the 3.0L setup. I think that the piston design has come a long ways since my build though. The biggest problem IMO was that there was not enough material between the top of the piston and the first compression ring, I have new pistons now from diamond and they look gorgeous. But as Guru found you can build a 3.0L right with out it burning anything but delicious fuel. Adams car boosts really fast with the 3.0L and RS6 hybrids, it comes in just as soon or sooner as my K04 car does.. with it running like shit I think I saw 3.1s out of the car on 20psi, I think it has low 2's written all over it when we can get a solid tune in it with it running well. I think I have some logs of it here with an MBC. I'll ask adam if he is cool with me posting it. BTW my car got 28mpg from grand rapids to minneapolis with a 3.0L 2.8 cams build 2.7 heads and rs6 hybrids. True story I have reciepts lol.

Sweet, awesome info. So what pistons did you originally have in your first one and what iterations have the pistons gone through to get where they are? What pistons does Adam have (I'm guessing the Diamonds that he was trying to sell for a while)? Where did you guys get them? Are the VAST custom pistons that I heard about a while ago the Diamonds? What compression ration do you have on your current setup, old setup, and Adam's setup? What other options are on the market? Love the gas mileage btw ha

toyota did studies on stroke vs bore to obtain displacement and they found that undersquare(larger stroke than bore) produces more mpg. This can be verified in the field because square or oversquare motors tend to produce less epa mileage stats. Just food for thought though.

As for going to 3.0 it will necessitate more headflow. the 2.7 heads are already at a minimum size to enhance throttle response. Upping the displacement on stock heads will shift the powerband down and up the torque. This isnt a problem with big turbos(a more likely cause for the lower mpg of 3.0 cars) since their power comes up top. The recent tuning developments seem to be fine without upping the displacement. While it wont be best for getting that huge hp number to brag about, you may be best off using a 3.0 bottom end, ported 2.7 heads, and 2.8 cams. The smaller 2.7 port size will make it more diveable as a dd by enhancing low end throttle response at the sacrifice of some top end power numbers. On the 2.7 cranks side, a smaller stroke is more stable at higher rpms. Eg. less bearing strain, crank strain. This is moot if the crank is forged but i dont know if they are or not.

as for revving to 8k, hydraulic lifters float at 7200 about so anything above that can cause damage or strain at the wrong time. Again this isnt an issue for huge dyno numbers as much as it is for a motor youd want 150,000 miles out of. If you want DD reliability id rely more on the turbos for power than the engine. in my book timing and compression(static) are far more wear inducing than boost assuming you have adequate intercooling and tuning. GT turbos with just the con rods upgraded should be sufficient to make a good long term reliable car as well as just about guarantee youre faster than everyone else on the road.

Well worded response. Either way I go, built or not, big port 2.8 heads with 2.8 cams are going in (I've got a good set of 2.8 heads and a bad set of 2.7 heads). And if I go 3.0l with my slightly smaller GT's, I'm wouldn't be worried enough about low end at that point to want to go small port just for the low end gains anyways (with that setup I'll have PLENTY of low end). Good explanation of the physics, however. When you talk about "upping the displacement on the heads," you're talking about intake port size, right?

Stock cranks are forged BTW. Interesting thought about the 3.0l MPG too.

[Europowerhaus]

or 81.5 (will fit with slight honing) made for 3.0l crank stroke.

Nah man, honing that amount of material would take FOREVER, Ive honed 3 of these blocks, that is not an option, plus everyone should remember that you need a torque plate for proper honing, I say 3 liter stock heads for around town, Im building my motor (dedicated track car) to have a 81.5mm bore with the 3.0 crank.

[wdbdy2000s4]

A motor with proper machining will not burn oil. There's plenty of VW/audi guys running aftermarket pistons/rings with over 30PSI of boost and no issues.

[julex]

The proper machining part is where it usually goes wrong. Even the smallest imperfection will result in uneven bore. I am myself leaning towards 3.0l crank but due to reliability issues people have with 83mm(+) bore, I am sticking with 81mm factory bore. All I need is 3.0l crank and 81mm piston designed for longer stroke, which can be obtained or made to order.

[NogaroAvant]

you can always run a custom 82.5mm piston with a 3L crank. No need to go 83mm...

[TweetsS4Estate]

I went 83.5 on the new build I believe. I figured it was fine with a girdle and I would rather get a perfect bore. Anyways my new pistons are still stock comp jibber.

[jibberjive]

Well, I'm leaning towards stock bore/pistons for reliability. I just don't have enough confidence in the 3.0l pistons that I've seen as options (though I haven't dug deep to see all of my options.)