320 (STandarD correction) has been my goal since I first got a S3. Really didn't think it was possible.


Mods/stock:
S300s v3.5 chipset + TQrings
PK crank breather system*
Two degrees cam retard*
intake gasket matching*
NGK BP8ES 1.0mm gap
PorKensioner/PKT
HeX-pipe
H-RMB*
'87 S4 FPR
stock air filter
stock injectors
airpump delete
airbox lid delete
belt driven fan delete
stock '86.5 mid exhaust

*changes since last dyno


SAE 313/308

 

there is something really strange going on under your hood

 

Very good Ken. I thunk you could get to 350 if you can run e85 and utilize the fuel's ability to take more advance and create more power from additional combustible mass in the chamber. 5% from the combustible mass increase and 5% from the advanced timing.

You may need to retune to 42lb injectors though.

 

Which radiator is that?

 

Very nice.... so what are the numbers with SAE correction (so others can aspire to them too)? ..

 

928 Motorsports rad, IIRC.

SAE 313 HP/308 TQ

SAE is a B. It was really tough to get over 300 at SAE air temps. STD air temp is a bit more realistic for the PacNW.

No knocks, BTW.

 

Ya know, it wouldn't kill a guy to put a little paint on that intake manifold.
Probably good for an extra 5hp too.

 

That is awesome! That is more than if I supercharged my OB! Awesome job and she has got to be a blast to drive!

 

Very nice!

Sorry if these are less than intelligent questions, but what is the 90 degree pipe in the front of the engine? And was the air box and plumbing hurting air flow? Just asking because I would have figured you'd have gotten colder air by leaving it on or going to a straight, larger diameter piping I've seen on some cars.

Just curious to better understand the logic behind the changes.

Thanks!

 

Nice work Ken!

 

At <3100 lbs with me and a half tank, it's a lot of fun.

Painfully loud with the RMB and cam retard, though. I'm going out now to put it's mod'ed pumpkin back on.


The 90° pipe is an oil/vapor separator/surge tank. Taking the airbox lid off will probably make less power on a street car, but I don't have a radiator or firewall seal so it stays cool.


Thx, Shane!


Notice how calm the red line is, even with very little smoothing. That's what the dyno runs sounded like. Couldn't really tell it was pulling the big #s. Do-dee-do-dee-do, just rolling along.


Except for noise, -2° timing doesn't seem to have any drawbacks. Same TQ as +2°, just a few hundred RPM higher. (Using a 32V'r, -2° is 'straight up', like a 16V cam would be set.)

 

Very nice work

 

Excellent work. Everyone with an S4 is waiting on you to buy one and start tinkering I bet!

 

Yes we are...

 

Ken,
As always a fascinating post. Although somewhat imprecise, it would be interesting to see your best estimate of the incremental difference each of these mods has made.

I have always believed the stock intake system upstream of the MAF to be restrictive so interesting that you have the filter intake cover removed. I modified a stock cover and cut apertures in the upper back to permit free flow of air. I also removed the firewall seal on the possibility that there is a pressure gradient at speed in front on the windscreen that might induce flow into the air box not to mention the lower induction pressure at the mouth of the box caused by engine vacuum. I felt it ran well but could not prove that. Unfortunately, in a house move, the modified cover got accidentally slung so no more progress on that one over the last two years. Hence my interest in what this mod may be worth on the dyno.

If I was to make an educated guess in round terms I would think the following might be somewhere close:
1. Chips 10 BHP
2. Exhaust 10 BHP
3. Air box 5 bhp
4. Cams 10 BHP
5. Rings [piston rings?] + optimal crankcase venting 10 BHP

This assumes good stock would around 275 rwhp- your thoughts in this regard appreciated

Regards

Fred R