Choosing a turbo for a fast road car

[thexav]

When you are looking to upgrade a turbo on a car what are the best choices?

Large Turbo
Small hybrid turbo
Small custom turbo

What should you look out for in terms of spool up and power bands? I guess a hybrid just bolts on, but do these offer much more than the stock option?

Are all large turbos really laggy or is there a way to minimise this?

 

[old-git]

Geez, that is a very long piece of string. This would need a small book to answer with any degree of usefulness. Far too many variables to give any sort of general advice other than don't do too big. But then, what is too big?

 

[SLEEPER]

And it isnt just small . big or hybrid . You can have a bit bigger or smaller and it can be a hybrid or not

Even different make/models of the same size turbos will spool up differently . And just changing the housing or fitting a billett wheel are all ways to change the way the turbo performs.

And then there are twin schroll turbos...........................

If you really need to know the answer you need each turbos "compressor map" and then of course you need to be able to understand it and relate it to your engine.

And if you have to ask the question whats a compressor map understanding one is likely to be beyond you as they are for most people ,

Thats ok though because as long as you have a specific car with a spefic spec then look up what results others have got and change accordingly

 

[griffindai]

Personally I wouldn't go big again, not too big anyway

On the last car I upgraded from a maxed out Td04-15t to a Gt28rs with 064 a/r exhaust housing (there's also the 0.86 which is a tad more laggy but hits much harder and holds the power longer) this along with other mods (3" DP, bigger IC, faster cams etc & shorter ratio gearbox) made for a fast road car (Saab 9000 Aero with roughtly 350/360hp) but I managed to get a GT3076R 0.86a/r turbo for a good price and as its a straight swap I fitted this instead. Basically turned it into more of a 100+mph car, didn't really get going until 75 in third but then all hell broke loose and it was off like a rocket. Added a good 100-120hp (dyno'd 450 but probably closer to 470/480 when I scrapped it) but sub 80 wasn't really any quicker....definitely less fun and got caught off boost loads of times.

So in reality it made it a slower car for day to day driving. I'm trying to avoid going the same route on this one.

Depends what your after really, and what car/engine it is

Hybrid turbo's are usually a pretty good bet for a nice fast road car....plus it's bolt on so you could save a fortune in labour costs

 

[TCJBOLDIE]

The 3076 needs a 63 AR turbine housing.
Re caught off boost just change down a gear

 

[griffindai]

The 3076 needs a 63 AR turbine housing.
Re caught off boost just change down a gear

I bought a 0.64 3076r for my last 9-3 but decided to sell in the end, should really have kept it as I had it for peanuts anyway.

Only really fitted the 3076 as it was cheap and apart from modifying the oil return pipe & fitting a 4" > 3" reducer for the intake was a straight swap, plus with selling the gt28rs I ended up £100 in pocket

Cracking turbo though, 60-100 was mental with this fitted (3.9 secs!!) but you had to be in the sweet spot for any fun with other cars or you just get left behind waiting for it to spool up. Or just keep it screaming in 2nd at 60-65 quick change up then let rip

I'm trying to avoid it with this car, really tempting to just slap a big Holset on there as the internals are good for 550hp but worried about loosing all this nice low down torque, nice & responsive at the moment. I the biggest I'd go is a 20T upgrade. I'm looking into a nitrous set up now just to give a little extra sparkle above 4.5-5k where my power drops off. Still pulls nice but feels like it could do with a little nudge here

 

[jarrus]

the 9-3 v6 turbo used quite a small turbo if my memory serves me well?

 

[griffindai]

Pretty small, I think it's it's a twin scroll td04HL-15t. Spools up very early on the v6. Just looking into a 19t or 20T upgrade

 

[jarrus]

twin scroll you say? nice...
didn't think you could get a 20t in a td04 frame

 

[griffindai]

It needs to be machined mate, I can get a ready build 19t for around £650 plus post & tax or get mine machined and have the turbo rebuilt with a billet 20T slightly cheaper (not much though!)

There's a Vectra opc (VXR) running a 20T in Germany with the JZW tune

http://www.saabcentral.com/forums/showthread.php?t=329513

 

[jarrus]

so yours is the 2.8t not the 3.0t then?

 

[griffindai]

2.8 mate, it's the same engine/box as the Vectra VXR. Insignia VXR turbochargers also fit but theyre 18t (I think!) but may aswell go for the 19/20t for the extra few quid