20VT Turbo Choices

Hi All,

For a reliable 300-320bhp on a none forged engine, then what are the current turbos of choice please?

With turbo technology moving on is there an off the shelf modern equivalent to the older GT28r, GT28RS/R, Superspool and stage 2&3 hybrids? Or are these still the best option?

Cheers
Jules

I guess it’s still all the old turbos then as possible options. If anyone has fitted a more recent generation turbo, or something different to the ones I’ve mentioned, then feel free to post.

Cheers Jules

There are plenty of new turbos available for the 20VT, not just the old RSR's but modern units with billet wheels etc, the best person to discuss this with would be Flea as he offers a good range of hybrid options.

I had my standard turbo shell refurbed with a new style billet wheel by a place in Southampton. Didn't have the exhaust side rebored or anything like that, made 290bhp with supporting mods.

Flea called it a stage 0.5 rather than a stage 1 when he live mapped it, so the new options definitely work

290bhp is way more then a stage 0.5, but if he said it was that stage I hope you were billed accordingly

sadly I was billed as a stage 1. I guess the other mods pushed it over a standard remap on a standard turbo. I did have to spend a long time walking up and down the small high street while I waited.

Hi Both, thanks for taking time reply. Good to know there are some more recent turbos out there to be fitted.

Hi Jules

You might find it's better to run a turbo capable of more power, but then run it well within its capabilities.

For example, a GT28R or RS will give 300bhp , but the turbo will be working hard - something around 1.2 - 1.4 bar, which generates lots of heat

By comparison, something like a GT2871R will generate the same airflow (and thus the same power) at a lower boost level - eg 1.0 - 1.2 bar. Bearing in mond the turbo will run at 1.5 bar or more, then you'll end up with a setup running well within its limits, rather than at the limit.

Just make sure you specify a smaller exhaust turbine housing to keep the lag to a minimum.

Running a bigger turbo is also better for when you inevitably get bored of 300bhp and decide that 400 would be more entertaining....

I'd be looking at new technology now. How about a G25-550? Chap who runs a YouTube channel called TeamPrawnRacing has one on a 1.8 Audi A3 race car. It made somewhere in the region of 450bhp at high boost but he has it detuned to 360bhp (IIRC) for a race series.

Thanks Nigel and appreciate your response. The larger turbo makes sense based on reducing heat and a smaller exhaust turbine / housing to reduce lag. The car won’t be used much as want to keep it long term, so I’m not too fussed on going down the forged engine / big turbo route.

Thanks for that I’ll check it out

Yup - that's what I thought too, and look where I ended up...

Haha! Absolutely, both your Sprint Blue and Moon Grey Coupes were / are amazing. It’ll be a test of self control that’s for sure as my last 5 cars have a total of 3100bhp.

I want to keep this Coupe in top condition and the miles down. Hopefully I’ll resist temptation but think 300bhp+ will be fine........

Hi Cyclone
I have a complete set up gt2871r 63 440cc injectors down pipe front mount uprated fuel pump etc and mapped by flea to 1.3 bar But I run this at 1.5 bar due to the extra add fuel when it was mapped , if you are interested pm me

this is what I'm running with lots of other mods.....running 1.4 and approx 400bhp ........yes I have to agree with Nigel its very entertaining