300hp 4JB1, and the quest for more power!

[paulthepilot5]

Gday all
Finally got around to putting the latest setup on the dyno. Just about reached the limit of the current pump, but have plenty of headway with the turbocharger, will be building a p7100 pump in the new year to take things further.
Specs:
301 HP / 636 Nm at the wheels
2.8 4JB1T
Inline A-pump, full fueling to 5000rpm
+50 4JB1 injectors
Borg Warner S200
Front Mount Air to Air cooler
Water/meth injection.
4JH1 head (for slightly larger intake valves)
ARP head studs
Upgraded valve springs and pushrods.

BD81BA48-253A-4630-B108-05F54A26F507.jpeg

Dyno Run:

https://youtu.be/ue8NWpsLJ5Q

9EA2676E-DB54-4A53-A8D8-B4470D797DF8.jpeg

[geeves]

looks impressive but how does it drive on the road?

[paulthepilot5]

looks impressive but how does it drive on the road?

Pretty good to be honest, i drive it everyday. It’s still making more torque off boost than peak torque on a stock JB1.

[paulthepilot5]

A video over the last 5years drag racing progression

[youtube] https://youtu.be/vRWD5n-lrr0?si=-aiPtS0VidZkF5XB[/youtube]

[Roadrunner]

I like the black paint, it must be a buzz to drive it, I'd probably drive it everyday too!
So what do you have planned for the next mod?

[paulthepilot5]

I like the black paint, it must be a buzz to drive it, I'd probably drive it everyday too!
So what do you have planned for the next mod?

When I’m not working on it I basically do daily it.
Reached the limit of the current pump, it was only ever built for around 250ish hp. Building a hotted up P7100 pump for it. It will be capable of more fuelling than the engine will be able to take. I guess the new goal with that is 400-500hp

[geeves]

At what point do cranks clutches and gearboxes explode?

[paulthepilot5]

At what point do cranks clutches and gearboxes explode?

Haven’t really found the limit yet, will be either crank or rods.
Clutch is always a problem on these with high torque. Went through a few types, a cushioned ceramic, double diaphragm clutch has been ok so far, but now at its limits. I now run a larger clutch, billet flywheel kit from NPC clutches that I organised with them, it should be fine at least till 850nm. The MUA5 is definitely a weak point (with high torque), I’ve killed a couple with lesser setup. The current setup is holding so far, having a focus more on higher rpm power than low end torque and also being a very light vehicle now helps. There are petrol guys running 600/700hp through them albeit lower peak torque. I have the stronger MUX5 gearbox (from the 4JJ1 rodeos) to go in if when when it fails. I also have a B&J planetary 5speed drag box I’ll go to when I get a bit closer to the pointy end.