I recently finished 'all the bolt ons' in an attempt to create more power out of my factory 4.0, and although I feel I did generate a very noticeable amount of power, this post is backing what some of you already know. Disclamer; this has most likely been covered multiple times before but every thread I read seemed to be arguing about it. Also, I did not dyno before, during, or after, so all my findings are seat of the pants... not too many dynos in small town Missouri.
Here we go!
I don't think I missed anything, started with MSD stock replacement ignition which helped, only because my dist. cap was so bad I'm surprised it ran. moved on to 703 injectors, ran a lo smoother after that. Added the 62mm throttle body and could tell the biggest difference so far, but still hit a wall. Did the 99+ intake swap and an AFE CAI as well as wrapped the aftermarket header the PO had put on... a little diff, still hit the wall. Finally did the exhaust, 2.5" all the way back, high flow flowmaster cat, 50 series flow muffler..... I feel it completed the mix, but still not what you'd expect.
Anyone who has said it on this forum, I completely understand and believe you, bolt ons are great but you are only going to get as much power as your engine is set up to provide.
I may be pulling an additional 15-20 hp, but I'd like to think all my efforts were to set up the perfect situation for a cam or a cam and a stroker, but without that, bolt-ons won't get you very far.

 

ye 15-20 BHP, maybe 5-10 to the wheels. Gotta go stroker or turbo/sc to get power.

 

lol at least the 50 series sounds great! I think a cam kit would be enough to really bring all my mods to life

 

Tune it now!

 

lol tell me more!


I don't know what else to do besides 'flashing it'

 

Cool post. Thanks for the feedback

 

Being its a odb1 you have to take the chip out of the ecu and have a company flash it,If any still do that kinda thing.

 

I'm fairly certain I recall seeing dyno proof that the bolt ons yield around 25 whp. seems fair given the ingredients.

 

I'll take 25! Thanks for the info!

 

Thanks for this! It's always great to hear real world feedback. You think you could get a video? I would love to hear how that sounds. I also want to do a 50 series on mine. With the intake, headers and full exhaust I can imagine it's probably the best sound you could get out of a 4.0.

 

Thanks and sure thing, I will try to get a video uploaded today. Hopefully my phone will do it justice.

 

they never do, but it will give us a little taste. Do you know what kind of headers are on there?

 

Comp cams has a 252h cam that works with stock valve springs and produces great torque. I'm running it in my 4.5L stroker

 

I'm still struggling to get the vid uploaded, error message says files to big, any suggestions? lol I'm still new at this stuff.

 

not sure if you're on the app or a computer but my phone never uploads videos. I put them on YouTube then imbed them to my post here. Or just post the link.