[John DiMartino]

I agree with everything Chris said in his above post. On a 24V,you do not need a free flowing air cleaner,and exhaust right away.You can add more power with just a minor fueling box.The air cleaner,exhaust does help,but it isnt necessay until about 325hp.The auto trans is a sore spot on these trucks.It needs to be addressed with some trucks as soon as you add more than 50hp,others will hold 75hp or so extra.
IMO for most people who arent happy with just a small box,they will need to do some trans work.Sometimes just a shft kit will hold things together for a while.To be honest though I recommend upgrading the entire trans at this time.If your going to pull the trans out,and go into it you might as well go thru the whole thing. Once the trannys done(this is by far the single biggest expense),you can add more power.I recommend diesel dynamics stage 2 injectors for 90% of the 24V trucks. This combined with a minor fueling box will deliver more power than you could ever need,and the torque will be unbeleivable.the truck wil be around 310-320RWHP at this point with about 700-750 ft lbs at the rear wheels,from 1500RPM on up..Driveablity will be excellent,very smooth and powerful.If you need more.get a major fueling box,and do some fuel system work (address the weak lift pump),then add a larger turbo and 400-450hp RWHP is about where you'll be,with about 850 ft lbs at the wheels.AT this point if your still not happy there are step 4 injectors and EDM injectors that will get you to about 500hp with a single turbo.If you want more than 500HP you need to go twin turbos or use Nitrous. Building these trucks is very fun,and satisfying,but it isnt cheap. i think reliability is great to about 475hp.At this point the boost you make starts to get to the point where you may blow the head gasket,also the EGTSs get high with a single turbo.The transfer case,rear ends,and axles have all been very reliable from my experience.
On the 12v trucks,simply putting in a torque plate,and governor spring kit will take the truck to the point of needing tranny work.If more is wanted turbo changes,and injector changes will be needed.
Anyone needing more info feel free to Pm me,I have made some mistakes building mine,and if i coud do it over id save a lot of time,and money.

 

[John DiMartino]

Cold blue.Ive had a lot of different exhaust systems on my truck.I can tell you that a 4"system is more than adequete.And it is much easier to route over the axle,and by the spare tire. The 4" system does not impose a restriction until the 570HP mark. At that point a 5" system would be of benefit.Until then i preffer a 4" system. I had both on my truck,and at 490 RWHP,I swear the 4" system has better spool up and response as well as better power,IMO. I have nothing other than my seat of pants to back this up but others on the tdr have felt the same thing too.I have considered necking down my 5" to 4 and dynoing to see if i gain / or lose power. I would buy a stainless system if you have the $$ it isnt much more money.Also get the resonator if you dont like a drone in the cab,this is very important if you have 4.10 gears OR a 5speed with 3.54 or 4.10 gears,and cruise at 70+ mph regularly. Also when i ran a 12.26 at 109.25 i did it with a 4" exhaust system,the truck dynoed at 646RWHP with the single turbo,and doing the math of 7100lbs and the 12.26 it requires about 800hp to do get the truck to the end of the 1/4 mi that quick. So dont think a 4" system is nt enough.

 

[John DiMartino]

cold blue , I highly recommend diesel dynamics injectors,they have an excellent balance of smoke/power.As for fueling boxes,when you go to the major fueling boxes that tap the pump wire,then you need to monitor fuel pressure,full time,IMO. At that time you need to have a pyrometer also,and trans work in most cases.Most trucks need just a few banjo bolts drilled or replaced,and a strong factory lift pump,and they are OK.A lot of the trucks have weak lift pumps and this is detriemental to power,and injector pump life.I recommend every 24V owner get the fuel pressure checked on there trucks with a temporary guage at least every 15000 miles if they dont have a guage.