inyerface

Hi all, this is my first post after a mate of mine told me about your site. I have a sierra 2L twin cam (not cosworth) which is about to have a complete engine refresh,as are the brakes and chassis is being seen to also. I am in a position to buy a supercharger at a good price and wondered if anyone could give me some advice as to what I need to do to the engine to prevent it from blowing up with a supercharger strapped to it!! All sensible comments will be listened to. Thanks, C.

Hectori

how much boost you will use?

inyerface

Hi Hectori, I believe that the boost level from a supercharger is set by the pully ratios used as opposed to a variable boost control on a turbo. I'm after information in the form of: Do I need to lower cylinder compression or increase the head bolt strength or can I just strap in on? It is an EATON supercharger which I think is a "constantly-engaged" unit and it has come off a Mini Cooper S. Cheers. C.

rallyslag

its an M45 supercharger your talking about
you will need to lower the compression ratio to around 8.4:1 if your going to run the standard pulley

you can either do this with low comp pistons or using a decompression plate

the cheapest method is the decomp plate you can get these from ferriday engineering (ferriday.co.uk)
also are you planning on using the bypass system that the mini uses? or just blank up the hole in the inlet of the supercharger?

rallyslag

Hectori

ah, you mean to you that type of compressor. im sorry, but my knowledge of them are quite little, so i cant help you. i thought you were to use exhaust gas type supercharger. sorry, my mistake.

inyerface

Looks like i have a lot of research to do!
I wasn't aware of a bypass but the whole point of my project is to try to get as much usable power and torque out of my twincam without blowing it up yet using the car on a daily basis. I'm going to experiment with redistributing the weight throughout the car as well to get it to handle better once the g-max lowering kit has gone on but another goal is to shut-up a certain cosworth saph owner who takes great delight in telling me that my T-C is s#*t compered to his "Cossy".
The reason for opting for the supercharger over a turbo is partly personal due to my name-sake (W.O. Bentley) using one to show the likes of Ferarri how it's done!!!!! but also I like the way the power is delivered . And besides, If I wanted a turbo Sierra then I could just buy one but as an engineer I prefere the challenge

møffe

again yhere are noboddy there can help with tuning the sierra DOHC engine.. dont worry, it have been done.expect arraund 170-200bhp. the cheapest way to doo it are. kompressor Intercooler, standart engine, with the new model headgasket.(you can go op till 0,4-0,5 bars on std engine) some pipe work and hoses, and bay a SMT6 piggybag or a more expensive ECU. you need 4 new injectores or 4 more. std injectores can max give 150bhp when its with boost.

http://www.vae.dk/index.php?id=230

there are some more small bits and pices, but here in DK you can build a engine like that for abaut 1-2000 punds depending on how mutch u want to doo abaut it.

the car on the pictures have a ROOTS SC16 toyota compressor, and they are giving 0,45bars on a dohc engine with std wheels. and it have a spicial feture, you can turn it off. it are having at kobling like a aircon. so you can turn it off. and its werry cheap. but the dohc are driving with a mapsensor. so you have to close the hose when there are boost on. but that is werry simple and cheap. on the brakes vaccum line there are a thing (i really dont know the name in english) but is making sure that air only are gowing one way . you need some of these(1-2). and putt them on the hose. there are proberly somthing i forgot. and somthing you dont understand(bad english, sorry) but the DOHC engine are good for tuning.

dojj

iTrader: (3)

one way valve

the only thing youhave to worry about is the fact these engines will blow head gaskets, and this is what you don't want to happen as if you don't catch it early enough, the head becaomes nothing more than scrap

møffe

hmmm. theay do have problems with the std headgasket that theay were fitted with when theay were new.but fit the new headgasket, that you buy from ford now and have been able too the last many years then no problems.

and you say that the head is crap... doo you have a DOHC sierra???

if not, then donŽt talk abaut it. its fine for tuning.. take a look at it. big valves and ind/ex channels.

the problem are that noboddy have been tuning the dohc engine in UK, but that dont mean that it cant bee done. and the gay diddent ask abaut what cant be done. but talked abaut what can be done.

dojj

iTrader: (3)

been doing dohc gaskets since, ooooh, around 92/93 so yes, i think i do know what i'm talking about
not that i'm saying the engines are crap or nothing, but if you snap the chains you take out no1 main bearing cap (been there, done that)
if you let the head gasket go then the head normally warps to the extent that you can't salvage them (been there, done that)
cams don't normally go, but tappets can be past it at 80k (been there, done that)
inlet manifold gaskets are another problem that needs solving (and you need new seals around the injectors because you can't get the buggers out and in without some difficulty (been there, done that)
the crank case breather that goes round the back of the head tends to corrode and give you no end of woes trying to figure it out (been there, done that)
and the never ending saga of weeping rocker cover and front cover and bottom cover gaskets is another problem that takes money rather than anything else to sort out (been there, done that, seen the film and even bought the T-Shirt)
not to mention the pourous rocker covers which crust up at any random age in their lives (working on an alloy one at the mo)

so yes, i think i know just a little bit about them

it's also cheaper to change an engine than it is to source a new head

møffe

theay doo have a tendense to crak between the valves on cylinder 2 and 3.. but if you think abaut it.. all the abowe things you talk abaut. i dont know a engine there dont have the same problem. zetec, pinto, cosworth. IŽve only know that tuners have forgotten this engine when theay were beassy with the cosworth engine and pinto..

i have been driving with my car (sierra GT) for the last 6 years. 4 of them tuned, and i havent been saved.. iŽve been taking 3 diffs. and been driving 104k KM with it tuned and 154k km. when i bought it in 99 i changed teh head gasket. and its been driving since. it was tuned when it had been driving 170k km. and i only changed the camfollowers. it was tuned with. piper cams bd285 janspeed manifold simons 2,5" eksost and a 57I kit. then it was chipped.. 140bhp and 183NM its max are 7000rpm. and you change the gears at 1Gear 7000. 2. gear 6500 3-4.gear 6000rpm. then i put on dyno last year. then it was 135bhp. thas was after 250k KM. ive lost 5bhp.. and last year i made a 16:85 quartermile.. bad engiene?? not if you ask me. its more like a engine the tunere forgot. just becourse there were a lot of cheaf pinto engiens laying arround.. but that don mean it cant take it.. it mean that noboddy have done it.. we have a good known (in dk) tuner. he build a couple af NA dohc sierras when it was new. with 300G cams weeber karbs manifold. and mecanikle cam followers a full ballance of the crank. and then on std pistons he got 200bhp on a NA sierra dohc engiene with full relailibillity.. belive it or not. but now im gowing for 160bhp in my sierra. just with a full rebuild and a new plenium (my design) if its works its good, if not. then i have a sierra 4x4 cosworth in my garage waiting for my GT to be put on pension..and waith for trottlebodys

but sorry its not abaut NA tuning now. we have a lot of sierra DOHC with turbo or kompressor here in dk. and with a good ECU you can make 200-250 bhp in them. and i know a cople of friends with them. and theay doo okay. but build them right. 200 bhp are max on std pistons and compression.

dojj

iTrader: (3)

i think you hit the nail on the head there, the dohc was the engine that no one bothered to tune, and so, there is a lack of tuning stuff available for it off the shelf

i think the best step forward would be to get the 2.3 bottom end and bolt it up
or do the whole 2.3 16V conversion, but then you need to worry about management and stuff like that

møffe

just becourse there arn no stuff (as you say) on the shelf, dont mean it cant be done.. but here in DK there are no problems with getting stuff for it.

but when ewery time somboddy are saing that it cant bee done, then i will do it. thats way its more fun to tune my GT than my cosworth.

foreigneRS

management is no longer a problem on any engine these days, the megasquirt system is well proven and very cheap for diy builders. will be using that when i eventually get round to turbo charging my 2.9 v6.

miltski

way to go dojj

dojj

iTrader: (3)

intresting debate, over here where everyone and their granny can sort a cossie, the dohc has flopped as an aftermarket engine swap because no one wants to tdo anything to it

but over on the continent (possibly because the laws on tuning are vastly different) it seems to have taken off

once i've got my 2.3 i'll be possibly heading towards some foriegn places to look at superchargers

møffe

its probertly right that its the laws there are the reson to that wee tune ower DOHC sierras, but just becourse that peoble in UK dont do it, that dont mean that it cant be done. if you try just a little bit to look inside the engiene. its having big(and i mean BIG) valves and other good stuff. and a std comp on 10,4:1 and i can doo manny 1000 of kilometers with that. but put a 4branch manifold and a chip and you hit 140bhp easy. and thats what i mean is big tuning potensial.. so what doo wee need more. vild cams and trottlebodys and a fullprogrameble ECU. try to put it together, i dont know your prises but try to call arrund

megasquirt + the wiring and sensors
trottlebodys
cams
4branch manifold.

and then see what you get. ofcourse the 2,3 scorpio/galaxy are better but its impossible to finde ower here. and its norman illigal to change the std top and blok. not to forget that the cosworth are a expensive car to have.

soo thats way i write what i doo, i mean that there are more in the dohc engine than you think in the UK. a lot more in fact.

miltski

all i want is a manifold to house a turbo! do you know where i can get one from møffe?

dojj

iTrader: (3)

the only limits to what you can modify over here is the cost of insurance (assuming you can get covered in the first place)

my insurance has come down by £100 but it's only me to drive now and no one else
before i had any driver over 25 and my wife covered but now the company have said "too many mods" and refused
i can see it getting to the point where i won't be able to afford to run a modified car, but until that day, i'll keep modding

møffe

dont turbo tecniks make one.. but you can make one your self. http://www.realpower.dk/

i know that the link are in danish. but i eksplanis perfect how to build a manifold your self. on the page theay build it for a toyota cupe. but the princips are the same. and in the examble there are stuff fore abaut 50 pounds. so if you cant weald and cut stuff your self tehn there problery peable arround you there can help you. the pipes and bending theay youse we call steam pipes. dont know what you call them but theay are with a thick wall.

the cheapest way to build one are to youse the std one on the dohc
engine and put some things on so the turbo fits.

but when we talk turbo/kompressor on a dohc engine then dont go ower 200bhp or 0,7 bar on a std engine. and get a good ECU. something like a megasquirt or better. depending on how deep your pockets are.

miltski

got a manifold now but engine management looks real expensive, yeah sure the megasquirt is cheap, but unless I can get a base map to get the engine running It'l be a nightmare surely?

I'd rather go with soemthing piggyback at least then i can use the normal ECU to get the engine running, then use the piggyback to put fuel in when on boost and retard the ignition,

I've been looking at smt6 (perfect power) to go onto fiesta rsturbo management, but is there anything else out there?

møffe

the SMT6 piggybag are a fine chip. but the standart injektores can give max 170bhp. you coud boy a cossi ECU and wiering, and put it on your sierra.

miltski

would that work though, as the twin cam is only 8v, and the turbo will be a t25 not t3, and will i need a cossie inlet manifold?

i hadn't thought of this as an option before as i thought the cossie lump was totally different in every way to the 2.0 twinky

møffe

too be honest. i dont know if the cosworth ecu and wireing will fit. but when you see the cosworth(bosch) injectores next to the std dohc then it looks like theay will fit down in the holes in the dohc top. but you need a new fuel line over the injektores. and then a new crank sensor. but if you boy a ecu from a 2WD, then it dont have eany knock sensores. and that woud be easyer to fit. but i relly dont know eany thing else. but it must be possible. you can fit it on at RST with KE-tronik standart. i cant se way not