Date: Sat, 26 Dec 2009 05:11:00 -0500
Reply-To: Greg Potts <greg@POTTSFAMILY.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Greg Potts <greg@POTTSFAMILY.CA>
Subject: Re: some observations on the power of an inline VW 1.8 liter
(Rabbit, Golf, Jetta) gas..
In-Reply-To: <6bc66ccf0912252237k1ac55e7cuab24120d3a505196@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Hi Don,
We had a 1985 Cabriolet from Jan 07 to August 09, with a 90HP CIS-FI
inline engine. Ours was a 3 speed auto, so the engine's powerband
remained largely hidden until you got up to about 70 MPH, unless you
manually shifted the transmission from 1-2-D to keep the revs up. With
the transmission in D it would usually shift at 3K so the perky motor
went mostly unnoticed until you got to passing speed and it woke up. In
my research I learned that the Cabriolet got the same engine as the GTI
model with the only difference being the GTI had a freer flowing exhaust
to gain another 7 HP.
The replacement for the Rabbit was a 1990 4-door Golf with a digifant
1.8L engine and another auto transmission, it doesn't have near the pep
that the Cabrio engine had, even if you do shift for yourself. But I'd
still put this engine in my vanagon in a heartbeat if I could find the
parts cheap
I'd be interested in hearing Doug Alcock's take on this, since he now
has an inline-4 CIS engine and an Auto transmission in his 84 westy.
Happy Trails,
Greg Potts
Toronto, Ontario Canada
1973/74/79 Westfakia "Bob the Tomato"
1987 Wolfsburg Weekender Hardtop
www.busesofthecorn.com
www.pottsfamily.ca
Don Hanson wrote:
> I finally put a tach into my 5sp inline 1.8l Gas VW (92 cabriolet) 84 low
> top faux Westie. Went for a drive this afternoon and watched the needle...
>
> At 55 I am turning about 3100..60 about 3400 in 5th gear. 70=36-3700rpm...
> That seems to be right near the bottom of the power band of this motor, with
> it's mild aftermarket cam and free-flowing exhaust. If I shift back to 4th
> it takes my revs right into the "meat" of the power..about 3700 at
> 55mph..The motor seems to pull strongly till 5500 rpms then tapers off a
> bit. It will happily pull full throttle off idle....but I cringe, treating
> a small motor/large load like that...I didn't have a choice in my old air
> cooled 36hp splitty bus, but with the 5sp...I try to not lug the inline 8
> valve 1.8 liter. I'm guessing I should limit my rpms to about 6500
> max...maybe about 6000 except in rare cases...
>
> So, when I was driving 'by ear'...I was usually shifting back (5th<4th) at
> the start of big steep climbs when I got below about 60...probably putting
> my rpms at about 4200, just into the higher half of the power...From that
> speed and rpm range I can usually accelerate up to 75 but I find it 'better'
> to just hold 65mph in 4th gear during long grades, to save wear on
> everything....No real advantage in winding out the little 'mouse
> motor' because if I shift up to 5th again at 75mph (~5000+rpms in my 4th
> gear)...my speed will slowly fall back until I decide to shift down as I get
> near 3000rpms or so...The motor feels unhappy...no, more like unproductive
> at anything below around 3000...Though it's fine to run along on the flats
> or in the city at 2000...I feel like I'm being needlessly hard on it if I
> have to accelerate unless I shift back and raise the rpms..My 5th is more of
> a cruising gear...not much acceleration or climbing in 5th..but a quick
> 'snick' back to 4th puts the engine in it's "happy spot" for power...
>
> Right around 3500 there is a 'semi-loud' band...where the harmonics seem
> to be a little "off"..not noticeable at 60+mph with the wind noise, etc..
> but in the lower gears climbing steep hills, there is that one
> narrow irritating rpm range. Probably the "Buzzy" stuff that everyone talks
> about with the Tiico engines...Doesn't bother me much as it only occurs on
> full throttle load and I don't do so much of that..
>
> These numbers...not exact. I was driving as I tried to track the tach,
> not running on a dyno.
>
> So for those who're curious about alternative engines in a vanagon...there
> is a little observed info about one of the (arguably) 'original' alternative
> engines found in vanagons...I'm happy with mine as my daily driver/work
> van/travel and camping van..
> Don Hanson
>
--
|