30-04-2013, 04:07 PM
If you keep the revs up with a big ass hotside, but keeping the boost down - just keeping airflow high, you'll find that it'll probably put up with more than you'd normally expect - I'd expect to see 300hp, peaking at the redline with a big enough, efficient turbo, but you won't get the massive midrange shove of a heavilly boosted petrol, it's going to be like an NA screamer, just with a bit of extra wheeze at the top end.
I've seen J4s make 250hp with 0.5bar so that's what, around 7lbs of boost... They're rediculously capable engines, tbh, I rekon in reality they're a better tuning option than the XU10s... Nowhere near as fragile... The fragility of the higher performance XU10s is just rediculous, for a 1.6 to make 125hp and have not even half of the fragile valvetrain problems that the XU10s have, yet the XU10s only produce 167hp is mad! I've seen TU5J4s make 450hp on stock internals before now...
I've seen J4s make 250hp with 0.5bar so that's what, around 7lbs of boost... They're rediculously capable engines, tbh, I rekon in reality they're a better tuning option than the XU10s... Nowhere near as fragile... The fragility of the higher performance XU10s is just rediculous, for a 1.6 to make 125hp and have not even half of the fragile valvetrain problems that the XU10s have, yet the XU10s only produce 167hp is mad! I've seen TU5J4s make 450hp on stock internals before now...
