i'd like to pick up another 10-20hp with my daily driver, but im not looking to rip apart the block. one option i came up with is to add some crower 403 cams and an aftermarket header to my ls engine. the motor currently has intake and exhaust for mods. again, not looking for crazy power, just a little more pep to help out in merging traffic and such.

what kind of basic setups are you guys running out there with the crower 403's?

 

ive heard great things about them personally.... i put those cams in a turbo LS motor and it was able to make power upwards of 8800rpm!!! Ill prolly end up buyin them myself next spring

 

definitely need more compression for those cams.

 

So what about 402's. Any gains with them?

 

Also I have an extra neptune rtp I can use and throw some extra timing at to help out the 9.2:1 compression

 

I'm interested as well. I just picked up a set of 403's a week ago. Definitely would like to know the in's and out's before installing these. Like what will I need to if I have to make adjustments to the idle or what have you?

 

alright peeps, back in the same boat with a b20 this time. for those that use the 403s, whats your valvespring situation. there is no reason to run anything but oem retainers they are good for 1000 more rpm than the rodbolts are, so a single valvespring looks like the best bet. i think supertech makes a set but i cant seem to find places that stock it

 

It seems like most people use Crower springs but I guess those require different retainers. Supertech seems to have a weird distrubition, since their only NA authorized dealer is a wholesaler. I assume you've tried THMotorsports and KingMotorsports and the like.

 

ive bought many parts from thmotorsports over the years. im going to wait until i get the cams to buy the springs, all of which will be going down over the next month or 2 so i can install the parts and get a solid tune on it when im off of work for easter/spring break. i do drive this car 20,000-25,000 miles a year and dont want any potential wear issues with ti retainers

i run the 85lb dual supertech springs in my turbo car and they are fantastic. 9200 rpm on the datalog at the track with 0 issues

 

It's too bad VTEC springs won't work -- you really wouldn't need much spring on 403s.

 

lol your tellin the guy who has an extra set of oem itr valvesprings. ive heard many people run the 403s on stock springs with stock rev limit. while i will set my limiter at probably 7200(maybe see that a few times a month) on my stock bottom end, i still dont think its worth the risk for 150 dollar springs and an afternoon worth of work

 

get the springs. Use stock retainers. I had a cammed LS. Crower 403's. Good street cam. Don't expect crazy power but expect more useable power. Get a GSR transmission. It will be fun. check my profile for power figures and my small build. kudos, and good luck.

 

good to hear. i dont want crazy power but would be very pleased with between 10 and 15 whp from 5000 or so rpm up to 7000ish. just trying to have some fun merging into traffic and passing slower traffic.

i already have a gsr trans with ls 5th in the car now. supporting mods will be edelbrock 4-2-1 header, 2.25" exhaust including magnaflow cat and straight through muffler and ill probably weld up a cold air out of my short ram. i remember reading a while ago on the forums on jeff evans website (rip forums) that a length between 30 and 36" showed best gains on all motor setups. i also have an extra neptune ill tune it with

 

I bet you'll get some pretty nice gains. Be sure to post your dyno results when you get her tuned.

 

ahh your gonna hate me but i probably wont be dyno tuning this car. ill drive around with the laptop for a week or so and get a good street tune on it, then maybe over the summer put it on the rollers for a pull or 2 out of curiosity at a local dyno day. i have another car that has priority over this one when it comes to dyno time as it really cant be tuned safely on the street.


research has told me that the 403s perform a little worse than oem ls cams up till 4000 or 5000 rpm. gotta figure out how bad it is. a few hp and tq here and there i can probably compensate for with a few more degrees timing i just dont want to loose like 10+ ftlbs. wait and see i guess. thanks for the help and replies in this thread guys

 

Nothing wrong with street tuning, as long as you don't convince yourself that you've gotten all you can out of the engine. I street-tuned my GS-R after I put in cams because I didn't want to pay for a real tune until my build was finished.

 

do you have the cams in yet?