turbo mounted in place of rear silencer!!

[stuartp]

some off you may know what im on about if you read ppc

but whats peps views on the method of mounting a turbo at the rear of a c20xe'd nova, in place of the rear silencer!! general thoughts fellas im not thinking of doing it or want boring sums and figures lol

cool idea yeah??
:thumb:

[ck]

seen it done on american cars lol, the main problem if i remember correctly what people had alot was the fact the turbo itself is lower than the sump so it cant physicaly drain its used/heated oil properly and hence used to kill turbos relativly quickly.

think they call it a remote turbo set up? i would assume the engine would lack response and be pretty lagy.

[CP]

Cool idea?
Maybe, maybe not depends how well its done IMO.

I can see some advantages and you ought to be able to get some reasonable gains plus you could feasibly use just about any turbo you came across making it perhaps easier for a DIY mod.

There are quite a few technical problems but not insurmountable. I think I would look to give it its own standalone oilsystem complete with cooler and pump so your engine is immune from oil issues

The soundtrack might be interesting with no silencer - could be consider cool by the yoof who like flamer kits

[Jack]

A turbo at the back of the car on the rear silencer? :wtf:

Thats going to have major lag issues surely. I've heard of people trying to make the turbo > inlet tract as short and as straight as possible, but putting it at the back of the car is going to give you at least a metre and a half of travel to the throttle body. Plus, won't the turbo run hotter? Seen as there's no direct air flow onto it as you get at the front of the engine bay, although I suppose you could rig up some form of underbody scoop to keep it cooler. Runs the risk of picking up FOD there though.

[Stuart]

its all about gas temperature/pressure causing the turbo to spin up....... therefore moving it about as far away from the engine as possible is a really inefficient way to do things... ie ****te

[craig green]

I thought it was one of them things people shove up the tailpipe like a whistle, to create a turbo sound....

[lj]

this was on a race car at goodwood festival of speed last year!

http://i13.photobucket.com/albums/a256/leezarins/leesloadedpics2438.jpg

[mikey14sr]

Yeah but due to packaging constraints that was pretty much the only place they could put them at the time without making the chassis wider or longer, and I suspect that it would have a dry sump system that would actually suck the oil back out of the turbos too.

[Adam]

By the time the exhaust gas has reached the rear silencer, they have cooled/stop expanding a lot compared to the manifold temps.

As said, a efficient turbo relies on gas expansion and heat(hence equal length runners/heat wrap on turbo manifolds), fitting the turbo 10foot away isn't going to work too well imo.

[Lee]

Yeah but due to packaging constraints that was pretty much the only place they could put them at the time without making the chassis wider or longer, and I suspect that it would have a dry sump system that would actually suck the oil back out of the turbos too.

Not to mention the engines in the back LMAO

I honestly cant see the point in a front engined car at all!!!!!

[Ash]

http://www.balancemotorsport.co.uk/products.asp?subcategory=Rear+Mount+Turbocharging&category=Turbocharging

;)

http://www.balancemotorsport.co.uk/main.asp?category=Project+Car


STAGE 5 - VERTPOWER REMOTE MOUNT COMPRESSOR
http://www.balancemotorsport.co.uk/images/205%20turbo%20stage%205.jpg
For this sprint we finally completed the remote mount turbo charger system. (http://www.limpetracingsystems.co.uk/video/205%20turbo%20lydden%20small.mpg) (right click and save as). Many strange looks from people which was to be expected i don't think anyone had ever seen a turbo hanging where the rear silencer used to be. In answer to your first thought - no there isn't any lag and it spools up quickly !
Why remote mount? Well the 205 1.9 engine wasn't designed for big boost and turbo heat it's open block design and exhaust valves see to that. Therefore we decided to look at remote mounting. Unfortunately the ideal place near the c of g longditudal location and below (i.e under the gearstick) offered no space. We decided to move the compressor further back. In the end the removal of the rear silencer saved some weight and meant the net weight gain of adding the turbo at the rear instead of in the front was less. Plenty of aircraft, bikes and cars dating back to the 80's have mounted turbochargers below the sump level which presents a challenge with scavenging the oil. Much like a dry sump relocates oil from the harsh environment of the engine, remote mounting a turbo protects the engine from it's huge heat soak and complicated plumbing with limited space.
Ultimately the best place for a turbo is often in the engine bay but remote mounting whether at the end of the downpipe, in place of the centre silencer or rear mount turbo in place of the rear silencer offers flexibility, lower cost and also benefits for racing with lower weight, lower c of g and cooler running.

http://www.balancemotorsport.co.uk/images/VERTPOWER%20TURBO%20205.jpg
For the initial sprint the car was not rolling roaded - it was operated with no dump valve, no intercooler and no bleed valve. At just 0.38 bar it should be achieving around 170hp and 170lb torque. The performance figures so far (drag strip will confirm in future) are 0-60 sub 6 and 30-70 around 4.5 seconds. The car is very quick and by keeping standard compression there is no lag with quick spool from 1500rpm.
These Vertpower conversions aim to offer a blend of performance with environmental conscience as the intention will be widespead installs to take advantage of bioethanol on smaller engined cars. Preferably older cars as they already exist therefore the biggest chunk of CO2 is eliminated. The 205 has actually improved light throttle economy with the compressor making up for the otto cycle engines inherent deficiency of operation below full throttle. Don't get me wrong though. I'm not about to suggest diesels are better....

OBJECTIVEASSESS THE IMPACT TO LAPTIME OF NEARLY 40% MORE POWER AND TORQUESPRINT TIME 1.75 LAPS 90.75 seconds ( -2.13 sec)
SUSPENSION
GAZ COMPETITION COILOVER KIT (http://www.balancemotorsport.co.uk/products.asp?recnumber=55452)
23MM REAR ANTI-ROLL BAR (http://www.balancemotorsport.co.uk/products.asp?subcategory=Anti%2DRoll+Bars&category=Suspension)
(http://www.balancemotorsport.co.uk/products.asp?subcategory=Anti%2DRoll+Bars&category=Suspension)POWERFLEX BUSH KIT (http://www.balancemotorsport.co.uk/products.asp?subcategory=Powerflex+Bushes&category=Suspension)
ECCENTRIC TOP MOUNTS (http://www.balancemotorsport.co.uk/products.asp?subcategory=Top+Mounts+and+Alignment&category=Suspension)
309 FRONT WISHBONES
GROUP A REAR BEAM MOUNT KIT
CORNER WEIGHTED TO 50% CROSS WEIGHT

ENGINE & GEARBOX
STANDARD 1.9 GTI with VERTPOWER (http://www.balancemotorsport.co.uk/products.asp?category=VertPower) REMOTE MOUNT COMPRESSOR INSTALLATION (now intercooled using a scrap 320D intercooler, intake temps 10deg above atmospheric at up to 0.5 bar constant)

BODYSHELL
STRIPPED OF ALL INTERIOR TRIM,
OMP CAGE FITTED,
FRONT AND REAR STRUT BRACES

TYRES
GOODYEAR EAGLE GSD3 195/50/15WHEELSSTANDARD 6JX15

BRAKES
STANDARD 205 GTI WEIGHT WITHOUT DRIVER
815KGHORSEPOWERESTIMATE 170hp @ 0.4 BAR (estimate 180HP @0.5 BAR)POWER TO WEIGHT RATIO 209 HP PER TON 0-60under 6 seconds (0-70 7.8 with 0.5 BAR)1/4 Mile TBA
VIDEOS OF THE 205 TURBO LYDDEN HILL SPRINT ARE AVAILABLE HERE (http://www.limpetracingsystems.co.uk/)
http://www.balancemotorsport.co.uk/images/VERTPOWER%20120PIX.jpg COMPONENTS AVAILABLE HERE (http://www.balancemotorsport.co.uk/products.asp?category=VertPower)




In summary

The extra horsepower has made the biggest difference in time reduction so far. However before you say you want more power if you look at the reduction for both lightening and suspension and cage compared to power that still brought a bigger gain.
On it's own power is nothing - it's how the car lays it down. With 0.38 bar of boost (now tested up to 0.5 bar with intercooler) the car handles it well. The performance is better than expected for 170hp due to the rise in torque which makes more of an impact to acceleration than mere hp.
So the verdict echoes the company ethos - do things in stages, make sure you have a stable platform before adding power and when you want to add more power look for more grip. In short keep things balanced..
thanks to all our customers for keeping the faith when we had no time to develop this car due to successful web and mail order sales. We look forward to a more active 2008 season with more modifications and more results.

[Lee]

Well you can't argue with that :)

[stuartp]

and thats the exact car i read about... very cool. keep the comments coming lads....

[ck]

imagine that same 205, they done it the old school/proper way, turbo mounted right next to the engine, with an intercooler, pretty sure it would drasticaly change the way it drives. it would allow them to run a larger turbo to help with top end power.

on a budget it woudl be a laugh lol and certainly diffarent, but the oil side of things is what will take a bit of thinking.
the turbo having its own oil suply might not be too good, it would take ages for the oil to get up to operating temps as oposed to it using the engine suply. maybe a preheater.

just hassle in my opinion, which will see much better gains if mounted in the conventional manner