Turbo Size Help
Discussion
Hi, Looking for some help I need to buy a new turbo for my TVR Chimaera.
Im doing a 4.6 Top hat Single turbo conversion. I bought a Turbo but I cant even get it down the front of the chassis its too big. Its a schwitzer and I believe its got a 1.40 exhaust housing, this is way too big for where I want to place it. Which is in a modified Y piece.
So I know there are some clever bods on here that may be able to offer some advice on turbo choice if I can pick your brains.
Its completely rebuilt top hat, cross bolted, 4.6 all arp. Its on the standard Pistons but I have ferriday decompression plates in there taking compression to 8.1 (I believe figures are up stairs)
I have megasquirt 1 Extra to do the fuel and ignition.
Its will also be intercooled.
Any idea of a suitable single turbo hopefully from a UK company so I can pick it up.
No idea of boost yet but I want it to be suitable sized for around 500bhp as I see these supercharged chims making incredibly good power at relatively low psi on standard compression. And if funds allow I would like to eventually fit forged pistons/rods so dont want to be buying another turbo.
Many Thanks
Neal
Im doing a 4.6 Top hat Single turbo conversion. I bought a Turbo but I cant even get it down the front of the chassis its too big. Its a schwitzer and I believe its got a 1.40 exhaust housing, this is way too big for where I want to place it. Which is in a modified Y piece.
So I know there are some clever bods on here that may be able to offer some advice on turbo choice if I can pick your brains.
Its completely rebuilt top hat, cross bolted, 4.6 all arp. Its on the standard Pistons but I have ferriday decompression plates in there taking compression to 8.1 (I believe figures are up stairs)
I have megasquirt 1 Extra to do the fuel and ignition.
Its will also be intercooled.
Any idea of a suitable single turbo hopefully from a UK company so I can pick it up.
No idea of boost yet but I want it to be suitable sized for around 500bhp as I see these supercharged chims making incredibly good power at relatively low psi on standard compression. And if funds allow I would like to eventually fit forged pistons/rods so dont want to be buying another turbo.
Many Thanks
Neal
speak to Owen Developments www.owendevelopments.co.uk
there technical bods are second to none and will help you out.
there technical bods are second to none and will help you out.
There is a Griffith about with a Courtney twin turbo set-up I believe .. seen it race a few times at Brighton Speed trials but I think it's had 2 owners since then and one of them has spent a lot trying to make it move driveable. It was pretty crazy at an Austec open day on the rolling road.
There is no reason why a single turbo wont work.
But again, there are cheap options, and expensive.
What sort of budget have you ?
Ive a couple of Turbonetics GTK-550's that I wont be using. One is likely for sale.
Bought a year or two ago and never used. So Brand new.
http://www.phantasmusa.com/turboneticsgtk.htm
It would meet your goals.
Holset, Borg Warner or other brands would likely be cheaper though for a biggish single.
But again, there are cheap options, and expensive.
What sort of budget have you ?
Ive a couple of Turbonetics GTK-550's that I wont be using. One is likely for sale.
Bought a year or two ago and never used. So Brand new.
http://www.phantasmusa.com/turboneticsgtk.htm
It would meet your goals.
Holset, Borg Warner or other brands would likely be cheaper though for a biggish single.
This one area where size is important and biggest isn't always best with small engines. As Boosted LS1 says, check flow charts and gather as much advice as poss from turbo specialists who understand head flow, A/R ratios etc. Too big and you'll never turn it, so lag will be a problem. Too small and tight and you'll throw it out of the exhaust pipe in pieces as a result of over-speeding. I agree that two small ones makes good sense (but not sequentially - use one turbo for half the cyls, and the second for the remainder) and this should help with packaging requirements and then you'll need an efficient wastegate for proper boost regulation, which can be part of the chargers or an additional device fitted into your pipework.
We deliberately have massive lag with our pulling tractors, but flow is essential from our very large, triple, sequential turbo set-up to burn high volumes of methanol with a rather extreme 90psi boost.... It does give us 3500hp from a straight six 10-litre tractor engine. Packaging isn't a problem and low-speed driveability is irrelevant when all we want is max power for 10-12 second bursts
We deliberately have massive lag with our pulling tractors, but flow is essential from our very large, triple, sequential turbo set-up to burn high volumes of methanol with a rather extreme 90psi boost.... It does give us 3500hp from a straight six 10-litre tractor engine. Packaging isn't a problem and low-speed driveability is irrelevant when all we want is max power for 10-12 second bursts
This is the turbo I wanted to use. It a Schwitzer from a truck I believe its brand new. But I just was not sure about that 1.40 exhaust housing. Well assuming 140 inside it actually means that?? Cat is for reference to how big this is. I reckon this will be sucking in anyone on the side of the road if they get to close 
Edited by neal1980 on Friday 19th March 10:37
Geoff Ashcroft said:
This one area where size is important and biggest isn't always best with small engines. As Boosted LS1 says, check flow charts and gather as much advice as poss from turbo specialists who understand head flow, A/R ratios etc. Too big and you'll never turn it, so lag will be a problem. Too small and tight and you'll throw it out of the exhaust pipe in pieces as a result of over-speeding. I agree that two small ones makes good sense (but not sequentially - use one turbo for half the cyls, and the second for the remainder) and this should help with packaging requirements and then you'll need an efficient wastegate for proper boost regulation, which can be part of the chargers or an additional device fitted into your pipework.
We deliberately have massive lag with our pulling tractors, but flow is essential from our very large, triple, sequential turbo set-up to burn high volumes of methanol with a rather extreme 90psi boost.... It does give us 3500hp from a straight six 10-litre tractor engine. Packaging isn't a problem and low-speed driveability is irrelevant when all we want is max power for 10-12 second bursts
No idea who you are....but WE NEED MORE INFO/PICS !!!!We deliberately have massive lag with our pulling tractors, but flow is essential from our very large, triple, sequential turbo set-up to burn high volumes of methanol with a rather extreme 90psi boost.... It does give us 3500hp from a straight six 10-litre tractor engine. Packaging isn't a problem and low-speed driveability is irrelevant when all we want is max power for 10-12 second bursts
neal1980 said:
This is the turbo I wanted to use. It a Schwitzer from a truck I believe its brand new. But I just was not sure about that 1.40 exhaust housing. Well assuming 140 inside it actually means that?? Cat is for reference to how big this is. I reckon this will be sucking in anyone on the side of the road if they get to close
It does look a bit big for a 4.6L engine. Being a truck turbo means it was diesel, varios debates whether diesel turbos can be run with petrol - many people do run them and dont have a problem. The diesel turbos I looked at tended to have inbalanced compressors and turbines (small turbine, large compressor - or was it the other way round?)Edited by neal1980 on Friday 19th March 10:37
It will work to an extent - but be prepared to change it if it doesn't spool.
Use Eric's turbo calculator to figure out the data. I've plugged in a 4.6 rover at 1 bar(14.7 psi) of boost and other conservative values:
http://www.not2fast.com/turbo/glossary/turbo_calc....
Edited by eliot on Saturday 20th March 19:30
Edited by eliot on Saturday 20th March 19:31
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