Date: Sun, 30 Aug 1998 11:52:50 +0100 (WET DST)
From: Imper
Subject: Turbo- not that simple!
Anybody care to talk about their turbo imps?
Date: Tue, 1 Sep 1998 18:02:03 +0100 (WET DST)
From: frank hoeffner
Subject: Re: Turbo- not that simple!
I'd like to take a shot at it. Mind you , I'm not a professional mechanic (Only shade tree) and mine was an experience with an Opel GT. 7 to 1 compression. Ideal For a turbo. You have to lower the compression on the Imp. $$$$$.
No.1
(You 've heard of turbo lag. You'll get that)
No.2 You have to build an exhaust manifold. No such thing on the market. You have to build it from scratch.
By the time you're done, you will be a fair welder. I guarantee it.
No.3 Now you bolt the turbo onto it and connect it to the silencer. Not so easy. Things that come to mind like space, heat etc.,you get the picture. Once done, you also connect it to your water system and oil system. Enter the turbo with pressure, exit without. You'll need to drill your engine and oil pan.
OK, you're half done.
No.4 Fuel system . I don't know much about fuel injection so I stayed with the carb. Webber. With the carb you can either blow through the turbo or suck. Problems with both ways.
When blowing through, you need to enclose the carb in a box to seal it. What to do with the throtle? Tricky business.
Sucking through, fuel shortens turbo life.
NICK, how am I doing so far? Jump in any time.
This is where I went wrong. In order to get more fuel on demand from turbo you need an electric fuel pump.
Don't forget to put a bypass for fuel. Mine exploded on first test drive.
Lucky. No fire. I gave up.
Or you can install a 930cc Japanese factory turbo charged engine, like one of the Imp owners on the list from Malaysia did. He likes it........A lot.........Frank
thread branched. See: Alternative engines
Date: Tue, 1 Sep 1998 23:55:44 +0100 (WET DST)
From: Nickcleak@aol.com
Subject: Re: Turbo- not that simple!
I tried both ways :
sucked through a stromberg CD 150 , that went too well , it was my first effort in 1982 with a big turbo , it must have been putting out about 160 bhp, i had a R 17 !
fuel consumption was 25 mpg , it was all wrong ,, but worked.....
later blowed through a single webber 38DCOE , that worked a lot better as far as drivability and fuel consumption goes ...
you only need to seal the air inlet face on the webber , my brass floats sank a few times due to the coninual pressure rise and fall causing the brass to fatigue .. they do plastic floats now ....
nick ..
Date: Wed, 2 Sep 1998 12:19:54 +0100 (WET DST)
From: Carsten
Subject: Re: Turbo- not that simple!
About the turbo discussion : WHAT MODEL WAS USED ? FROM WHICH CAR ?
and, wouldn't it stress the engine too much ? the crankshaft bearings will get worn out soon, won't they ?
Carsten
Date: Wed, 2 Sep 1998 23:01:23 +0100 (WET DST)
From: frank hoeffner
Subject: Re: Turbo- not that simple!
Turbo unit came out of a Mitsubishi1600cc Mirage.......
You get more HP, you get more stress, you get shorter engine life. But its all relative. As Nick put it: Watch that lead foot and you'll be alright......Frank
Date: Wed, 2 Sep 1998 23:52:54 +0100 (WET DST)
From: Nickcleak@aol.com
Subject: Re: Turbo- not that simple!
well i used a Japanese IHI RHB51 which was the smallest i could get in 1984 , it's not water cooled i am sure more suitable ones are available now ...water cooled would be an advantage ...
No , the imp engine is very tolerant of high power out put .. and despite popular opinion the peak forces are not a lot greater , the power stroke is a similar force but lasts for longer ..
My Tuftrided crank which i bought in 1974 did 100,000 miles before , AND 100,000 miles after the turbo conversion ..
nick .....
Date: Thu, 3 Sep 1998 02:06:49 +0100 (WET DST)
From: Gary Henderson
Subject: Re: Turbo- not that simple!
If the same car goes at mostly the same speeds, (often governed by traffic anyway!) then the forces & stresses are unchanged.
If one was to 'use' the extra power output by fitting such a boosted engine into a larger, heavier vehicle, then its life would be greatly shortened.
Cheers
GaryH
Date: Thu, 3 Sep 1998 16:59:30 +0100 (WET DST)
From: Adrian Saville
Subject: Re: Turbo- not that simple!
It isn't - that simple.......
A point I would like to add to Frank Hoeffners letter - look at a commercial design of about the same engine capacity and power of the unit you are trying to acheive
A few come to mind but the Lancia Y10 Turbo seems the most relevant 1000 cc Y10 Fire engine - there must be something in a scrappers - try find-a-part in the UK
I would imagine that the turbo is tuned about spot-on for imp
Another point is to provide a wastegate or at least a blow off to reduce inlet manifold pressure (especially on the overrun) (BANG!)
Regards
Adrian
Date: Fri, 4 Sep 1998 01:03:57 +0100 (WET DST)
From: frank hoeffner
Subject: Re: Turbo- not that simple!
>Another point is to provide a wastegate or at least a blow off to
>reduce inlet manifold pressure
Most do have waste gates built in [my Mitsubishi Starion whistles, needs new spring], oil & water cooling.
Also important, intercooler.The air is much denser with it, therefore more of it goes to the engine and I think it reduces pinging.......
Nick, can you tell us more about the head you use on your Turbo Imp?
How did you work the injectors on your fuel injection? Did you have to drill holes for them?
Frank
Date: Fri, 4 Sep 1998 19:54:21 +0100 (WET DST)
From: Nickcleak@aol.com
Subject: Re: Turbo- not that simple!
My first head :
a full race big valve head with combustion chambers enlarged to give a compression ratio of 8:1
My late head:
i have just got a brand new L4 head modified with large valves and ports , it is a very nice thick casting and should give excellent mid range torque . the Compression ratio is 9.25:1 , a little higher this time as i have programmable fuel and Ignition control .
Injectors are fitted into a webber 28/36 type inlet manifold near the cylinder head .
The ideal place to fit the injectors on a high rpm motor is some distance from the valve , but maybe another time !
nick ...
Date: Fri, 4 Sep 1998 19:46:09 +0100 (WET DST)
From: Nickcleak@aol.com
Subject: Re: Turbo- not that simple!
if mine shows very little wear after well over 100000 miles what life does that give a standard imp engine ! I do have a tuftrided crank i suppose ... but i did drive very hard on many occasions ! traffic the last few years has reduced the chance for this , hence i am using a new head shortly , designed for low to mid range torque ...
i maintain that it doesn't increase wear to any noticable degree .... on other engines as well as imps , if the installation is well thought out ..
Nick ....