Hello again guys, thought id call back in..!!
Ok, I did a lot of development work to my truck when I had it and was maxxed out reliably at around 190hp & 360 ft lbs , and was at the limit of the stock internals really, since I had the HG go twice- the compression is too high for any more cylinder pressure. It made all the power between 1800 and 3800rpm as it just couldn't breath any higher. Clutches that wouldn't slip when it came on boost were abit of a problem which is why I eventurally went to the VGT turbo and ecu control. People said the gearboxes are weak but I never broke one. Desperately needed higher axle ratios as you were upto 4500rpm in 5th all the while!
Anyways I finished up with:
T28 then a GT2056 VGT turbo at 22psi.
2.5" exhaust with a custom elbow (factory one is the most limiting part)
Isuzu 3.1 nozzles.
Vp37 / 300TDI 10mm pump & head. A lot of work to this. £800!
Custom bar & plate top mount intercooler - wanted to keep the a.c !
Initially the standard 99 on ECU heavily remapped to suit the 10mm pump, then a bodylogic ecu for the VGT turbo.
HeavyDuty 3.0DI clutch and 6 puck plate, 2.7 flywheel machined to suit. D22 input shaft.
To be honest a decent remap, K&N filter and essentially a good exhaust with custom elbow and the T25 turbo doing 15psi will see 155bhp on a good engine is generally fast enough.
Tim..