how much hp do you think you could get on the 2.8 engine w/o a supercharger just keeping it straight n/a.

like new injecters, cams, ecu, everything except boaring.

and how much usually is port and polishing?

the thing is ive become kinda bored latly and i want to start a project to see how much hp i can make my car w/o forced induction.

 

with everything including new pistons/valves and p&p stuff some blueprinting. i would think may be in the low to mid 300hp range.<----this is all just a guess. there is a person on the 12v forum on aw that is doing this to his audi 90 12v and after exceeding $50,000 on parts he is looking to be pusshing around 330 hp n/a.

dont be discouraged by this. he wants to be the fastest 12v around. mabe you could be the fastest n/a 30v around.

p&p can be very expensive. it is not realy hard just time consuming. people have dome p&p work on my IM is seems to be about 40 hours to do and the heads are only a few hours a piece. if you dont want to do them yourself call around to machine shops and get quotes. some might want to see the parts before they give you a final quote. you should also look around for a spare engine to do this on wile you still drive yours. doing a lot of work like this will prob take some time to do

 

PnP is probably around 3-400. It's very time consuming and I wouldn't suggest doing it yourself. I've PnP'd a few DOHC 4 Cyl heads and it was at least 10 hours worth of work. It did make a noticable difference though.

As for injectors, you don't need them until you start to run lean, buying them for no reason would be a complete waste. Maybe after PnP'ing the IM and heads you might need a slight increase in fuel.

I'd say your first mods should be the top end.

PnP
Complete Valvetrain
Cams
Chip/Tune
TB upgrade


That should be about at least 25+ hp and an increased redline.

Then I would move on to the bottom end

Even though you said you didn't want to, you should have it bored to AT LEAST 3L. I would go with high compression pistons, like 11.5:1, I think it was after about 12.5:1 where 91 octane just isn't sufficient enough.


The 2.8 12V or 30V just isn't a powerhouse and isn't the easiest thing to make powerful. Remember the saying "N/A, the expensive way to go slow". If I had a 30V, I would just go with an SC.

 

Don't forget about the MAF!

Anyways, I wouldn't bore the engine to a bloody 3.0L... there is a reason the S4 has a 2.7L... they decreased displacement to increase strength -- audi engineers thought it was a good idea, and the S4 is only 250 hp. So boring to a 3.0L, and making MORE hp than an S4 -- not wise, IMO.

 

yes forgot about the MAF.

As for boring.

There is no reason not to. This is not going to be a boosted motor. NA still endures a **** load of stress but not as much as a boosted motor. I personally think it would be fine at 3L. I haven't pulled the heads off my 2.8 yet, so I'm not exactly sure how the sleeves look. If there is a bunch of meat on them, I would go ahead and bore it.

 

Yeah but you'll still probably have fairly high compression at 300 hp... am I wrong?

 

If he has 11.5:1 CR pistons, then even with 2000 hp, it's still 11.5:1.

On a boosted motor it's possible to overboost and that will raise compression.

 

just to let you in on a little secret. the objective of BOOSTING is to increase the amount of air and fuel, not the cr. the cr has to match the fuel type used, nothing else.

 

PnP
Complete Valvetrain
Cams
Chip/Tune
TB upgrade




Those mods are over 25hp, Ive have p&p stuff on my car, it makes a noticeable difference. Tap has a sick 30v chip that is a 18hp gain.Agressive cams are good for 12hp, all the P&P is good for about 10 to 15hp,dont forget about intake, theres 8hp for cheap price.

 

yeah, I don't remember where I saw it but one guy took pics of his intake and injector ports and they leave a lot to be desired. kinda remind me of my oldsmobile in the fact that they through it together, it ran, and they sent it out the door, with so much that could have been done to it.