We have been getting quite a few questions lately about the Edelbrock 4730 Camshafts on a naturally aspirated application. Yesterday day we decided to upgrade the springs, retainers and drop a set of the 4730 Cams into an in house project car. The Test Mule was an 88 CRX equipped with an internally stock B16A, ITR Intake Manifold, Omni Power 68mm Throttlebody, AEM Short Ram Intake, and Authentic Hytech Header.





With everything installed and ready to go it was time to hit the dyno for tuning on the S300.



The end result was pretty good overall, The 4730 Cams picked up power and torque just about everywhere and were able to carry it fairly high into the RPM range. The vtec crossover point also smoothed out considerably.

What we have learned so far with these camshafts is that they are working well in moderate compression naturally aspirated engines (up to say 11.5:1 compression). Anything over that compression in a naturally aspirated application these camshafts aren’t ideal for and there are better options.

In addition to the solid gains in the moderate compression naturally aspirated engines these are making great gains in the vast majority of turbocharged engines that they have been tested in.

 

Nice gains. How did U degree them? How much is V2V?

 

Just did these on my b18c1 with essential the same boltons.

 

Were dropped in and used with stock cam gears.

Very similar

 

I bought these from you guys, shouldve asked for a discount for a dyno of these, saved you the trouble :-p

 

nice to se someone test these with full results. you guys keep up the good work!!! btw nice tensioner!!!

 

Nice work guys!

Thanks for posting your results.

What changes in fueling and ignition timing did you notice during the initial pull?

I'm more so wondering what parts of the curve required more tuning

 

With a little play with the cam gears (while knowing V2V limit caused minimum separation) could result lot better results. Always well worth testing a few settings. Also, nice to see these are working 0/0, not like some big PR machine products.

 

Thanks! The tuning was pretty straight forward, The vtec engagement stayed the same and i ended up pulling out 1.5 degree of timing. For fuel it needed richened up as the cams leaned out the previous tune pretty significantly.

 

was the car previously dyno tuned on the gsr cams? or was this the first dyno tune it had?


Posted from Honda-tech.com App for Android

 

It was fully tuned on the previous setup.

 

You could add the tune to the S300 vault to give your customers a decent base tune.

 

Good idea..!

I think i still have that FTP site /login somewhere. I honestly need to upload a new updated folder as i've done a very good amount of tuning in the last 3 months.

 

 

I tried to update it recently and it was gone.

 

I'll see if my host can maybe do something on my website, so we can start that up again, i know that helped a few people.

 

sweet!!

 

What kind of vacuum have you seen at idle with these cams?

With my stock PR3 cams, I was having 17" or so of vacuum at idle, and with these Edelbrocks all timed up, I'm around 12".

Tested for vacuum leaks, set up stock idle controls, etc etc.

Edelbrock told me "I *think* that the non-vtec cam lobes are stock, but don't hold me to that"... something along those lines.

I've seen several dynos now (yours is an exception though) that show increased power BEFORE VTEC as well as after, a reported 'smoother VTEC crossover', and now my reduced vacuum at idle (12" instead of 17"+). All of these things seem to point to the primary lobes having slightly higher duration than stock (b16 or gsr) primary lobes.

Just curious if I have a more serious engine problem, or if these cams give others the same kind of vacuum at idle as myself.

 

FYI for anyone in Cali interested in these. They DO pass the smog sniffer! I just passed today in my 97 GSR. Ran stock head and valves with itr springs, AEM SRI (for smog), dc 4-2-1, stock gsr cat with 2.5" cat back, and ran my stock ecu for smog. And of course these cams.

 

For those that need installation help.

http://www.edelbrock.com/automotive_.../4000/4730.pdf

 

Mac have you tried these cams or know of others to have tested them in a B18c setup ?

 

For my own personal Hondas, no. But I have had a few use them for slightly higher NA setups, and one turbocharged car. Both were B18C1s. The turbocharged one was not much more impressive than a CTR camshaft, but the NA car did quite well at over 187whp, with about 6ft/lbs of torque more than an ITR. I think they'd do well for a person who had some CTRs and wanted a wee-bit more powerband and still be legal on the street. But I'd still get Toda Racing over these.

 

Ok thanks I have a set on there way for a B18c2 bottomend with ITR pistons and a complete ITR head,Rocket is sending over some valve springs for it and I have a PerformerX manifold to go on the build so I was just interested in how good they are.

 

LS/Vtec Turbo here with B18c1 head (low boost, 9psi)

These cams made a huge difference in mid-range (the low/secondary lobes seem to be way bigger), VTEC crossover (smoother), and in VTEC.

Had to back off some ignition timing in VTEC and move my ignition tables a little bit to the left (more retarded) due to the increase in flow that these valves offer from 2000-5000, in boost and in part throttle.

YMMV.

10/10 would get these cams again.

EDIT: Sorry, forgot to mention, in comparison to the stock GSR cams.

EDIT2: Also, my vacuum issue was because the car was not broken in yet (0 miles on it). Once a few hundred miles of break-in came into play, vacuum was much closer to normal (20-22" vacuum at idle), and the car idles exactly where I tell it to. Only slightly rougher than stock cams.