Dyno results: 2.6 liter short block

[JShadzi at aol.com]

Remember, tourque is in the bottom end, HP is in the head.  HP is a function of toruqe and engine speed, the higher your peak TQ happens in the RPM range, the higher your HP #.  By simply more aggressively camming this motor or retarding cam timing to shift the TQ cure up, you'd easily make bigger HP #'s.

>From what I know, Chris's head was mildly ported, nothing crazy, and the 272 cam isn't terribly aggressive either, like I said, from an engine with the stroke, known head flow, cam tuning, etc, these results are quite acceptable.  Sacrifice a bunch of that TQ down low and shift it up 2krpm and you'd easily start seeing much bigger HP #'s.  With the right head I bet you could dyno that motor close to 200whp, but that would be a very high revving, heavily flowed and cammed motor, and would have cost A LOT more money to build.  For what Chris put into his 2.6, he spent a marginal amount more than he would have putting in a new 2.3, i'd bet it would have been a few hundred $$ less.

So, if you do want a motor with bigger HP #'s, and you want to make HP with that kind of displacement, you'll be addressing the head, not the bottom end, you could easily make 114hp with a 1.8 8v motor with basically some porting and a cam, but you'd never have the TQ of this motor.

Javad

>the 28% figure comes from
>http://www.engineersedge.com/calculators/horsepower_automotive.htm
>I'm not sure what formula they use to get that, something ratio between
>1/4mile and weight.
>
>as for what's expected etc... I'm really curious what the limiting factor is
>on the N/A 5cyl motors. check out http://www.tsr-performance.com/ the claim
>170bhp from a 10v 2.3 and 185 from a 2.6 with the same head. Maybe these
>aren't really streetable motors, but quite frankly for the price, I'd be
>dissapointed if i didn't see something close to that with all the attitude
>of a full race car. If the 40 year old carburated 1.8l 4 cyl pushrod motor
>in a Turner MK IV can make 120hp at the fly wheel, why can't a much newer
>much bigger fuel injected motor achieve similar or better efficiency? For
>all that work your talking about a 10-15hp gain over stock. the way the
>powerband works is neat sure, but 10 bloody horsepower?! I would love to see
>what's going on in the head/intake. it seems like a good port/polish would
>really make a difference. Then again maybe the I5 just isn't capable w/o
>forced induction. Personally, I think it is, but I'm no Engineer(yet).
>
>my .02.
>
>regards
>Brendan
>
>"If God had intended us to walk he wouldn't have invented roller skates."
>Gene Wilder, Willy Wonka and The Chocolate Factory.
>----- Original Message -----
>From: <JShadzi at aol.com>
>To: ""Brady Moffatt"" <bradym at sympatico.ca>; ""Brendan K. Walsh""
><bkwalsh4201 at hotmail.com>; ""Chris Darringer"" <cdarring at pacbell.net>;
><quattro at audifans.com>
>Sent: Friday, January 30, 2004 1:55 PM
>Subject: RE: Dyno results: 2.6 liter short block
>
>
>> Its all pretty hard to say, especially considering different dynos and
>their respective correction figures.
>>
>> The value of dynoing a car is in just that, having some sort of
>quantifiable figure to use _relatively_ against future runs, on the _same_
>dyno.  Trying to accurately extrapolate crank HP is very difficut and
>typically not very valuable.  IME, a Dynojet dyno will pull about 20-25% out
>of the driveline, a dynodynamics dyno will need a higher correction figure,
>dynapack less, etc, etc.
>>
>> FWIW, Chris really needs to take a bone stock NG back to that dyno to have
>a good reference to where he's really at.  On that same dyno I've made over
>290hp at the wheels, and seem many cars with over 400 at the wheels (an A4
>1.8t with 410whp to be exact), so when I see Chris's 114, and maybe some
>optimization would get it to 117hp, its kind of pointless.
>>
>> Needless to say, I think Chris's results are what I'd expect and
>definitely within' the range of what it should be.
>>
>> Javad
>>
>> >I thought 25% (3/4HP left at wheels) driveline losses were commonly
>assumed
>> >for RWD applications. That would mean a 33% (4/3) multiplier to get back
>to
>> >crank numbers. It might be even higher on quattros. No BTDTs, though...
>> >
>> >Cheers,
>> >Brady
>> >Urq, 4kq, Z
>> >
>> >-----Original Message-----
>> >From: quattro-bounces at audifans.com
>[mailto:quattro-bounces at audifans.com]On
>> >Behalf Of Brendan K. Walsh
>> >
>> >> (1) Max power at the wheels is 114.2 hp and max torque is 122.4. If you
>> >> make the (overly-simplified) assumption that hp and torque are 25%
>> >> higher at the crank, then we are looking at around 143 hp and 153 lbs
>of
>> >> torque.
>> >
>> >I thought it was more like 28%?
>> >
>> >
>> >_______________________________________________
>> >quattro mailing list
>> >quattro at audifans.com
>> >http://www.audifans.com/mailman/listinfo/quattro
>> >
>>
>