come on people post up your numbers with hks 280"s with bolts ons and stock tubro. So whats everything making?????

 

Bump I'm interested too. Anyone with an idle clip? Would be great.

 

ive seen them idle its really not as worse then 272"s

 

I made 356whp and 349ft/lbs at 21psi, 93 octane. My mods include 3" TB no cat, HKS RS intake, Fighters Garage LICP, Hyperflow FMIC and a Walbro 255 Lph fuel pump. Here is a link to my dyno sheet, https://www.evolutionm.net/forums/sh...d.php?t=143767

 

j/c if anyone here had the 272's and then switched them for the 280's? I would like to know their opinion.....cause I'm in the market for cams right now.....

 

I heard that if you want to run 280 then youll need a some sort of EMS....

 

don't 280's necessitate the changing of the valve springs and possably lifters?

 

Believe it or not they don't While 280s have higher lift, they retain the same duration as say 272s. If you plan on raising your redline to above 8K RPM, then a valvetrain upgrade becomes necessary.

 

I think it's a requirement if you want the FULL POTENTIAL of the cams....otherwise I'm pretty sure you can get away with the stock head...

 

388/408 on C-16... 357/345 on pump. all except for exhaust. Meth injection soon...

 

you dont "need" valvetrain or an ems, where do these rumors come from. People call me and say "I hear if you get 280's, you need a completely built motor with a gt42R or the cams wont even spin"

"i hear you need a 3.8 liter stroker with 280 cams or you lose power"

i dont where people get these stories from. those are a little exaggerating, but still. HKS 280'S WORKON STOCK VALVETRAIN, THEY WORK WITH A REFLASH, AND YOU DONT LOSE POWER LOWEND, ITS ALL LIES PEOPLE

 

NoLimit is correct. 280's work better when flash optimized to help with the idle, however upgraded valvetrain and EMS is not required. If idleing like stock is what you need, then EMS would be helpful, however. I went from 272/272 to 280/280. Idle was rough sometimes with a/c. An ignition system in good order and a BOV that does not leak is a must. GReddy w/single spring mod will not cut it on 280's as it leaks at idle and screws up the afr. I am currently VTA now with the 280's and idle is better than ever. When setting the idle, turn on lights, foglights and a/c to set idle screw. If you do not, when you need the headlight, a/c and your radiator fans turn on, you will have trouble idleing as the rpms will be too low. The downside of the 280's is that any cams increase the likelyhood of the P0300 random misfire code due to noise in the valvetrain. The other code which is common is P0507 idle rpm higher than expected. If you set the idle with 280's using my method, it will be at 750 with a/c, lights and radiator fan, however using none of those accessories the idle will exceed the threshold the ECU sees as "normal" and will trigger the code. I have installed many sets of 280's and most get the idle code due to how the idle has to be set.

As far as dyno numbers go, here is a dynosheet from a few months ago that does not represent the current state of tune. Keep in mind it was tuned for drag racing which rpms do not drop below 5000rpms. There was some knock on the lower end of the pull from 2000-5000rpms as the un-natural boost spike comes on. You would not experience this timing pull while on the dragstrip.

DYNOSHEET FOR HKS 280/280 COMBO

 

...Alert! Please do not expect to reproduce these hp/tq numbers on 280s and meth...

Some dynos have been known to READ HIGHER than others...I mean a LOT HIGHER...just fyi, kthxbye.

 

agreed, but you do lose lowend. That is a fact. Higher duration = less low rpm power.