What Mods Add A Lot Of Bottom End Torque....??

 

Not a lot of the normal mods available will help bottom end torque. Some will cost you torque, in favour of a boost higher up the rpm range.
The only way I know of to boost it at a lower range is to add forced induction.

 

Torque is a function of displacement and BMEP [primarilly compression ratio x VE].

4 valve per cylinder engines usually have inferior [to 2 valve] low under 2200 rpm torque [for equal displacement] because the air speed into cylinder is lower [more valve area slow the speed down].

Very light shot [25-30 HP] of Nitrous coming in early can add 50 lb/ft at 2000 rpm.

 

Q45tech,
I always thought nitrous was meant to be shot at high RPMs?? like from 4000k+?

 

Extra oxygen is extra oxygen.

Nitrous is a constant volume of flow per second yet an engine is variable consumption based on rpm.

A 100 HP shot [say at 6,000 rpm] 5252/6000=0.87 x 100 or 87 lb/ft.
At half the rpm the twice as much [per cylinder gulp----intake valve open time in milliseconds] nitrous gets in each cylinder so 87 x 2= 194 lb/ft ----at 1500 rpm twice again so 392 lb/ft.

Why you gotta be careful at low rpms. Use progressive systems to limit torque to what the rods/pistons can stand.............25 shot>50 shot >75 shot as rpms build to keep torque gain somewhat constant.........tricky to fuel correctly.......so little time in 1st and 2nd gears due to fast natural engine acceleration.

The other problem is time delay [in milliseconds] from nitrous nozzle to the cylinder.....fuel from injectors is closer time wise than nitrous so 2,3,4 revolutions of engine before the nitrous gets to cylinder.......super rich then ok and next jet [25>50]transistion the same problem over again.

Electonic progression systems: pulse the nitrous solenoid to try to deliver a progressive increase as rpms build........works somewhat but solenoid open/close delays need to be analysed carefully to build a reliable long lasting system.

A job for a real expert and losts and lots and lots of extremely careful fine tuning [days weeks months] lots of dyno/street time and lots of nitrous to get it right.

But you can use nitrous at launch in 1st gear------CAREFULLY.

Lots easier after 1st gear as the rpms are only 4000-6500 rpm in the other gears. The rpm range limits the torque gain RANGE to 60% variations or less.

Really need a piggy back add on computer to make the precise calculations for GEAR and rpm [plus nitrous pressure variations at nozzle==distance to tank] to control added nitrous and fuel [plus variable ignition advance reduction as % of nitrous changes] if perfection is desired.
What to do just before 1st to 2nd shift, during shift and how to bring back nitrous all in a second.......precise control.....not available of the shelf..........$3,000-$4,000 time and materials could do wonders with longevity.

Most take the easy way and positive displacement [EATON type] supercharge with intercooler to gain a measly 25% torque at ~~launch rpm.

 

Wow,that was hard to take in.
Anyways, 7lbs of boost with a Stillen SC & a 55 shot gives a good kick down low. I have a window switch that turns on at 3900 rpm, a WOT switch and a push button down by my foot to stay off the nitrous in 1st & 2nd gear.

 

So if I wanted to add like 20 ft lbs of torque to a 05 mt which has only 260 ft lbs I would have to get FI or Nitris? Does anyone have experience with the 260 engine?