Engine/Transmission (1994 - 1998) Suggestions for "mild" power upgrade?

[abranz]

Hello, I've read literally hundreds of posts regarding engine power upgrades but I'm confused and hope I can get some suggestions.

My 98 stock 12v, nv4500 has difficulty accelerating between second-third and the third-fourth shifts when pulling my trailer. I try to increase the rpms between shifts but it defuels. I would like to improve this drivability issue but don't know which way to go. I'm not really looking for massive power upgrades and don't want to break the bank (have too many other projects). The truck runs fine, valves are adjusted, and there are no known problems. Any help would be appreciated.

Anthony

 

[ttbird]

BHAF

4" exhaust

3000 gov. springs

#5 or #10 fuel plate

That will get you started without breaking the bank. If you want more and you may not cause you'll be surprized at how much faster you go. But money is the only limit with 12 valves. Oh almost forgot gauges a must. :-laf

 

[Signal73]

The 3Kgsk will give you full fueling until 3K rpms, may be what your looking for instead of defueling @2500. They also have a 4K kit, which you need to install HD Valve springs for. The 3K is around $125.

 

[McLaughlin]

Hello, I've read literally hundreds of posts regarding engine power upgrades but I'm confused and hope I can get some suggestions.

My 98 stock 12v, nv4500 has difficulty accelerating between second-third and the third-fourth shifts when pulling my trailer. I try to increase the rpms between shifts but it defuels. I would like to improve this drivability issue but don't know which way to go. I'm not really looking for massive power upgrades and don't want to break the bank (have too many other projects). The truck runs fine, valves are adjusted, and there are no known problems. Any help would be appreciated.

Anthony

I can fully understand. I've done a sequence of mods to my 97. I started with an Air Cleaner. I'm not sure how much it helped the power but I could tell the turbo spooled up a lot faster(the turbo whine was a lot louder anyhow). Next I installed a new transmission, did the KDP, and 3K gov springs, 15 degree timing, and a 4in exhaust. Those four mods made a REALLY noticable improvement in performance. My transmission was really toasted so I'm not 100% sure if it was primarily a transmission problem or what but my impression was the 4in exhaust probably provided the least improvement as compared to the gov springs and timing. I then installed gauges (should have done it before the transmission replacement but didn't have the time) which didn't do anything for performance but helped my piece of mind. Next I installed stage II injectors and a #10 plate and again the performance increase was extremely noticeable. From what you mentioned, you may want to invest in at least a boost gauge and a EGT gauge. Stock, my boost ran about 25 psi after the #10 plate I can hit 34 psi. EGTs went from 1000 to 1300. I'd suggest the following sequence first: 3K gov springs, 15 degree timing, and slide the stock plate forward(supposed to help performance). Second (or first): gauges (won't help power but when starting to do the other upgrades it will help protect your truck. Third: #10 fuel plate or 215 injectors (or stage IIs) (you can go with a bigger injector (really need gauges if you start going to big injectors ) but from your description it sounds like you aren't really looking for lots of power just power in a different rpm range. Also, if you start going to more aggressive plates and big injectors you will reach a point where you will need a new air cleaner and exhaust/turbo). I didn't suggest an air filter upgrade or exhaust upgrade early because I'm still not sure how much improvement there is over the stock filter and exhaust.

 

[arthr31]

hi,

I recently had the fuel pump timing changed to 16*. Very noticeable in the driveability-- I'd do this in the near term, the 3k gsk is also probably good for you since it'll let you fuel beyond the 2200 rpm range. Good advice here from all.....

 

[abranz]

Many thanks to those who responded. I forgot to mention I have both boost and Egt gauges. I had it timed by a diesel mechanic but I have no idea to what number. Anyone know what the 3k gov. springs do? I mean what are they doing inside the p-pump to increase rpm before defueling. Probably dumb question but could the spring kit or fuel plate harm the pump? Thanks, Anthony

 

[arthr31]

I don't know about harm, but what the 3k spring kit will allow you to do is push the trucks RPM right up to 3000 without it defueling. So, with your current configuration, if you rev past 22 or 2500, the truck will rapidly loose power because of the existing governor springs. With the 3000 kit, you keep on fueling past those numbers. It's pretty radical, between the turbo kicking in, the noise, and quick speed, you need to mostly keep your eyes on the road as you approach 3000!!



you might want to call the mechanic to find out what degree the pump was tuned to. I think, if he/she did it by stock numbers, it'll be at 12. 5 or so... That's not what you want...

 

[bkroupa]

I have the 4k kit without the valve springs & it made a huge difference pulling a trailer with the 5 speed. It allows you to run it up to 3k or so with no defueling. The 3k kit is not much more than what the stock 98 has, go with the 4k kit & use your foot as the rev limiter. If you decide on a plate, I started with an 11 & wound up wih a 10.

4" exhaust is nice but not really needed if you replace the muffler with a free flowing one & loose the cat. A stock airbox minus the snorkel will flow plenty for what you outlined.

Best mods IMHO on mine, 16 deg timing (gained mpg & some power), 4k gsk for exteing the shift points, 10 plate for passing , The BHAF & the 4" exhaust are nice building blocks, but made no real noticable gains or EGT reduction.

 

[burnin oil]

I hope that I dont get in trouble for this but go over to diesel truck resource and do a search for "free GSK". They seem to have it working for under $5 I did the 4K in my 175 pump and it really makes the truck act like a car rather than a tractor. If you still need a little more get your timing set to approx 16 degrees and spend the money for a TST 10 plate and a boost and pyro gauge. You will think you are driving a muscle car instead of pulling your trailer. Good luck and happy bombing.