Author Topic: 1.5 diesel + supercharger = feasable? (Read 15447 times)

gldgti · « **on:** April 09, 2006, 04:55:43 am »

hi guys! its been a long time since i posted anything much on here, and a lot has hapenned with m golf (rabbit to you guys) since then. its lowered all round, has a fornt anti-roll bar, a new coat of blue paint and is looking quite tidy.

as you can imagine, a car that goes around corners fast is even better with power, which is something my 1.5 obviously lacks, and im not going to go through the old "how do i get more power?" routine... the engine mods already are:

1) timing advanced to optimal
2) 80mm intake pipe and modified airbox - cold ram air
3) 2" striaght back exhaust with dual downpipes
4) max fuel screw trick

to guess, i'd say ive gained 5-10 hp... well..., at speed, on a cool dry day it might be that anyway, the ram air helps a lot - but thats a truely arbitrary guess. anyway, thats about the limit to the modifications... this baby has done a lot of miles and is still reliable and economical (avg about 48mpg), though this is easy to wreck the economy with the fuel screw so far in.

the caar also runs on bio now and then... which seems to clean up the exhaust a LOT

anyway, apart from these modifications, i havnt dont a great deal to the engine... heres where my crazyness comes in...

i know that turbos and things seem to be too much fuss for a n/a engine, esp my 1.5... i hanve been thinking however about the feasibility of a supercharger...

my tentative plan is somehting like:

use petrol golf EFI manifold with long runners, and a toyota mr2 supercharger, belt driven with an electromanetic clutch, running low boost (in the range of 5-10psi).

any thoughts would be appreciated. i think this might be the kind of thing im looking for, something to give her some more power and torque right through the rev range, keep the exhaust free flowing and happy revving, and no pump mods since adjusting the fuel scre already gives me more than enough fuel all the time...

cheers guys,

aydan

Baxter · « **Reply #1 on:** April 09, 2006, 05:17:06 am »

Yeah, I have access to a reasonably priced G60 from a MKII Golf G60 and wondered about fitting that to a Diesel.

RabbitJockey · « **Reply #2 on:** April 09, 2006, 06:11:36 am »

i think that the power available from a torquey diesel+the instant boost of a supercharger would be pretty hard to beat. but a supercharger still does the same thing as a turbo charger, so like everything has said repeatedly, oil squirters will be very desirable, unless of course you plan on not pushing the motor too hard.

tylernt · « **Reply #3 on:** April 09, 2006, 07:43:24 am »

I asked the same question, and the answer I got was that the heroic cooling efforts are required on a turbo due to the increased exhaust backpressure. A supercharger will not have as much of a problem with heat so you could probably get away without the oil squirters, especially if you intercool without using an LDA (no LDA = less fuel = less heat).

Baxter · « **Reply #4 on:** April 09, 2006, 07:48:42 am »

I wonder if the G60 will bolt into place in a Diesel, wonder if there are any clearance issues with the pump?
Would be nice to use all VAG parts.

Baxter · « **Reply #5 on:** April 09, 2006, 03:47:39 pm »

S'pose you have the added benefit of being able to use a 4-2-1 exhaust system also. Cooler under bonnet temperatures, infact it sounds ideal, there must be a reason why no one else has done it?

RabbitJockey · « **Reply #6 on:** April 09, 2006, 03:55:09 pm »

i'd like to see any kind of a supercharged diesel, but a 1.5 seems even more neato to me.

kyledallas · « **Reply #7 on:** April 09, 2006, 04:50:53 pm »

I read a thread on another site today... a Mitsubishi site... it seems
that a very common mod in the Diamond Star world is to ELIMINATE the
factory oil squirters... it seems there are some main cap oiling issues at high rpm that are fixed by plugging the factory squirters....
Which are essentially methods of heat control for the pistons..
I have also found BRAND NEW intercoolers.... alluminum fins, ends, and
polished for $200 to $300 .... I found them at this price from 3 different
companies...decreasing your charge air temp.. whether super or turbo
puts you ahead in the game....
I am currently headed this direction myself.. on a na 1.6..
thermal coating on turbo piston tops, chamber, valves.... $200 NEW intercooler, Rebuilt turbo at factory or modestly improved boost....
I sure don't want to sound like the enemy of squirters... if a td block
was avail to me I'd be on it... with the squirters on line...
but if the piston temp is being controlled with charge air temp and
heat barrier on top... and you're not going "boost nuts"..aren't you in
the green zone???
If you want to supercharge... Go for it... I like to see the home-brewed
power..but find a way to attack the heat.. better pistons, squirters, intercooler, thermal barrier coating whatever... good luck whatever you choose.. K

kyledallas · « **Reply #8 on:** April 09, 2006, 04:57:01 pm »

Check out these cheap and nice intercoolers

www.alliancelink.com/users/joshdodge/ic1.html

www.spooledmotorsports.com

www.rabbidperformance.com/products.php?cat=29

If this isn't cheap enough for you.... print these prices and take'm to
the junkyard and have your used parts guy get you a Cooper S
intercooler for less...they are efficient and a nice small size.. would
also be easy to mount up front...

Kyle

RabbitJockey · « **Reply #9 on:** April 09, 2006, 05:02:15 pm »

i agree, in alot of turbo diesel applications the oil squirters aren't needed, my dads friend has ran many many n/a engines with a turbo setup for years with out any problems. just i would that if you're going to be pushing the motor they'd be a good idea, turbo or supercharger, but it seems like that may be false with the info you 've shown here.

gldgti · « **Reply #10 on:** April 09, 2006, 11:09:58 pm »

thanks guys,

im glad to hear positive replies from all. it seemed to me that a supercharger would be the ideal solution with the 1.5, with it being a simpler engine, but happy to rev hard, and with no factory turbo bits available in australia.

i also liked the idea of having the good exhaust system like has been noted above, and hence keeping a "cool head" so to speak.

btw everyone, i've been reading with great interest about this bizzo of insulating precombustion chambers and, as an up and coming mehcanical engineer, and diesel enthusiast, i'm being sucked into a bit of an obsession i think. this may be my future.... so thanks guys.

aydan

jtanguay · « **Reply #11 on:** April 10, 2006, 05:07:19 am »

man that would be one powerful diesel. If you had the proper pulley you could probably get full boost at low rpm, making it a torque MONSTER. just lookout for bent rods if you go too low. A nice small one could give good results and maybe create a sleeper.

oil squirters for a supercharged engine? I'm pretty sure you don't need them for that. Main reason you need oil squirters is because the turbo will create back pressure and when the exhaust valve is open and the piston is pushing the exhaust gas out it will be working harder to do so, as well as soaking that heat right into the piston itself. You would need to be running some serious extra fuel to even need piston oil squirters without a turbo. Just get a free-flowing exhaust system and you're laughing. :lol:

I wonder how much a set-up like this would cost. I know you can get those pseudo turbochargers that basically have just the compressor side and a pulley connected to a high ratio gear mechanism. Would be do-able on a car without a/c for sure.

coating your pistons/valves etc wouldn't be necessary, but my guess is that it would help retain heat where it is needed most during cold starts. if you have the money great, if not... no big deal.

Good luck if you choose to undertake this project! And please post some pics of how it will look like

RabbitJockey · « **Reply #12 on:** April 10, 2006, 03:55:35 pm »

aussie vw guys, they're crazy, from what i've heard theres next to no parts available, they gotta rip apart Seats...

jtanguay · « **Reply #13 on:** April 10, 2006, 05:57:17 pm »

engines over there are fairly pricey too... since they last so long out in the warm climate.

gldgti · « **Reply #14 on:** April 11, 2006, 04:58:45 am »

i hadnt really considered the 'all VAG' parts option of using a g60 supercharger... can anyone give me any info on these? i guess the big thing would be the option to possibly "bolt on" the charger in a good spot, however i'm not afraid of doing some fabrication and design work, so really, any suitably sized compressor would be fine, providing i could make it fit somehow.

also, can you guys tell me what i would actually need to have in the setup?.... im not really familiar with forced induction so im not sure...

on the macro-scale, i was sort of thinking, have the charger set up on a (i hope im not grilled for this :? ) vee belt, between the IP and alternator. i've got clear air into the engine bay with my aluminium grille so a cone filter very close to the charger itself would be next to the radiator. then, probably use a (as looking into engine bay from front) right hand exit EFI manifold from petrol golf, to plumb an intercooler (maybe scavenged from a volvo or saab, theres a few of them over here) between the manifold and the charger.

what i need to know about is what kind of stuff does a supercharger need so i dont do something bad to my engine.... i appreciate its got to be very different from a petrol engine setup, but is it as simple as having the charger running all the time, and it just blows and blows no matter what... or do i need some kind of pressure relief for when i'm not on the throttle....

thanks guys

aydan

Author Topic: 1.5 diesel + supercharger = feasable? (Read 15447 times)

Baxter

Baxter

Baxter