Edelbrock vs. 450r Carb

[Gatekeeper]

Thinking of upgrading my carb.
I know the 450r is cheaper, so leave cost out and just compare the carbs +/-
With my stock bore, K&N, WB exhaust, cut airbox lid, which one will give better gains, reliability, easiest install, easiest adjustment (ive never jetted a carb!!)
Thanks

[2muchquad]

leaving cost out of the equation...go with a fcr:D

[Gatekeeper]

Thanks :rolleyes:

[GPracer2500]

I've never seen any comprehensive testing of an Edelbrock on a 400EX. I'll occasionally here anecdotes about seat of the pants feel. But I'm always wary of that.

I know first hand how deceiving non-quantitative testing can be. If you can't attach a number to it (could be mph, or seconds of time through a set course, or numbers on a dyno screen, or quad lengths over/under versus a second quad of previously established performance) it's very hard to put any stock in it. A friend and I once had two 400EX's at the dunes. One was mostly stock but with an FCR. The other had some mild engine work with a stock carb. We both felt like the FCR'd bike was faster. It just plain felt faster! You'd get off one and go straight to the other and form an opinion. Then we took them to the drag hill and actually raced them. The stock carb'd bike with a little motor work killed the FCR'd bike with no motor work. One was definitively making more power even though the other one felt faster. It's funny how differences in throttle response (for example) can really skew a seat of the pants impression of overall performance. [edit: Don't misinterpret that my description of that experience as a knock on the FCR, I'm not dogging the FCR one bit. The bike with the FCR would have been even slower without it, no doubt. It was the motor work on the stock carb'd bike that made it faster.]

So that's something to keep in mind as you look for advice. It's not my intent to discourage anyone from throwing in their $0.02. I'm just saying--things aren't always as they seem.



The only good testing I HAVE seen for the Edelbrock was on a DRZ400. It was done on a dyno by a very experienced tuner using an a/f meter. The tuner walked away with a poor impression of the Edelbrock. The issue is in the way it works. Edelbrocks don't separate the different fueling circuits like conventional carbs. That's what makes them "easy to tune" (an oxymoron in this case, IMO). There's a single adjustment point for changing rich vs. lean (not counting the AP adjustment). On the DRZ it was impossible to get the fueling correct at all throttle openings and all RPM ranges. When you adjusted the carb to clean up the jetting in one spot you screwed it up in another. Needles were changed, calls where made to Edelbrock--nothing worked.

Here's how it went.

--The light blue line is as delivered from Edelbrock.
--The red line is with the "stock" needle adjusted to try and fix the top end richness. Power improved drastically but the bottom went so lean it ran very poorly there.
--The green and dark blue lines are with the second needle (not included with the carb, btw). It was a little better but the original problem remained.

--The maroon line is an FCR (with minimal tuning), just for comparison.

http://img.photobucket.com/albums/v699/burned-drz/EdelTesthp.jpg

To get all-around performance that's even acceptable they had to give up a lot of potential power up top do to richness (basically, something very close to the blue line). The owner of the bike did report that even with it's significant shortfalls, he felt it was better than the stock CV carb that comes on the DRZ. The stocker was not dyno tested, however--so who knows how it would actually stack up.

Would the same thing happen on a 400EX? I don't know for sure but I have no reason to think it would be any different.

Meanwhile, there's the 04/05 TRX450R carb. I've seen some dyno testing for that setup too. A quick search turned up this test performed by Venom some years ago: stock carb vs. 04/05 450r carb. This 400EX had a 416 high comp piston, cam, and other mods.

http://www.trx450r.org/forum/uploads/post-327-1103578521.jpg

Pretty impressive difference. So impressive, in fact, that the absence of a/f data makes me wonder if some of that difference could have simply been one carb being jetted better than the other. Maybe, maybe not. I do think the tester had a clue about what he was doing so I bet most of that difference is just in the carbs, not the jetting. Whichever, the results make for a compelling case for the 450r carb, IMO.

If I still had a 400EX and wanted to upgrade the carb I'd probably get a 450r carb. I doubt they have the RIGHT NOW throttle response an FCR provides but 1) I bet peak power is pretty close to an FCR, 2) they can be tuned "properly" (unlike an Edelbrock) and 3) you can get a brand new one from Honda for about $160 plus shipping. As long as you can deal with the minor modding needed to make it fit, it's hard to see the downside.



$0.02

[2muchquad]

If one wanted to upgrade a 400ex carb then for the money a 450r carb is hard to beat.BUT imo its hard to beat a fcr,they dont come on the performance 4 strokes for nothing.Sometimes throttle response is more important than outright power imo.The fcr made a huge difference on my 385 ex,its hard to even fathom how much of a difference it was.Naturally theres always somebody that has had a bad experience with them.They are worth the time to set them up with.

[zrpilot]

Originally posted by Gatekeeper
Thinking of upgrading my carb.
I know the 450r is cheaper, so leave cost out and just compare the carbs +/-
With my stock bore, K&N, WB exhaust, cut airbox lid, which one will give better gains, reliability, easiest install, easiest adjustment (ive never jetted a carb!!)
Thanks

I've had both and agree with GPRacer2500s' comments. I believe the FCR will make slightly more HP then the 450R carb, I could not get my 400EX to run right on the FCR. It had a low RPM(2-3K) bog that I simply could not get rid of. When I switched to the 450R carb, it virtually eliminated this problem. Now when I ride it and I need to hammer the throttle, I'm not second guessing whether it will fall on its face!

[Gatekeeper]

GPracer2500 Wow great information. I have seen a few Edelbrocks go pretty cheap on eBay and thought maybe this would be the way to go. Looks like 450r is the way to go, short of spending +500 for a FCR.
Oh well guess I'll have to learn how to jet:p

I know its been covered elsewhere but I will need a 04-05 450r carb, throttle cable, the 06 and up wont work, right?
What jet kit will I need.
Any recomendations on jetting?
Need anything else?
Thanks for the help!

zrpilot- still got any of the adaptors?

[zrpilot]

Originally posted by Gatekeeper
GPracer2500 Wow great information. I have seen a few Edelbrocks go pretty cheap on eBay and thought maybe this would be the way to go. Looks like 450r is the way to go, short of spending +500 for a FCR.
Oh well guess I'll have to learn how to jet:p

I know its been covered elsewhere but I will need a 04-05 450r carb, throttle cable, the 06 and up wont work, right?
What jet kit will I need.
Any recomendations on jetting?
Need anything else?
Thanks for the help!

zrpilot- still got any of the adaptors?

Yep.. I DO have some left. PM me for details

You will need:
Carb
Cable
450R fuel line (much easier with this!)
Oh yeah, of course, a zrpilot adapter!!!!! LOL!!

For jetting:
Main: Start at a 175 (mains from the stock 400EX carb will work!)
Needle: Stock, middle notch
Pilot: Try the stock one at first, but buy a 50 just in case

[Gatekeeper]

Thanks for the advice!
PM sent