04 Phenom CE

G

greenmeansgo

Member
Long time Bob's user, but I got out of karting before the crash. Just now opening the can of worms again.
I have an 04 Phenom, in excellent condition, that I had a good bit of success at smaller tracks. Will now be running a track just shy of 1/4 mile, medium bite Florida clay, and decent banking. Will be running adult akra clone. Track seems to like pinks and blues in the 50ish range.

I have old notes for a few different ways I ran the kart, but I think I lost any indication of what worked best.
For the most part, I have slight variations of:
55.2ish left
46ish nose
60ish cross
1 1/2" Front stagger
1" Rear
+0.75 LF
-2.75 RF
8 & 12 Caster
39 1/4 Rear track

Got a new motor and put weight in the normal spots to make minimum weight and ran it for the first time in 8 years last weekend just to shake everything down. It ran surprisingly well considering.

Just looking for good starting numbers for the 1/4 mile application before I hit some scales and start fine tuning. Thanks in advance for any input. Joe
 
You should be able to run little more left closer 57 %, Less LF pos camber .25, less rear stagger 3/4", NO toe out run it straight up.
Clone motor ? what weight ?
 
Flattop- New tires also. Needless to say, I dove back in headfirst. Only thing not new is the kart. But, the phenom is a mean chassis. Was really good to me back then. And you would really be surprised at how nice it still looks after 15 years.

Racing promoter- Will be running 325 and 350 class. Will keep weight at 350 though. All the other numbers look satisfactory? Other than the left, LF camber, stagger and toe. Thanks again. Joe
 
greenmeansgo said:
Flattop- New tires also. Needless to say, I dove back in headfirst. Only thing not new is the kart. But, the phenom is a mean chassis. Was really good to me back then. And you would really be surprised at how nice it still looks after 15 years.

Racing promoter- Will be running 325 and 350 class. Will keep weight at 350 though. All the other numbers look satisfactory? Other than the left, LF camber, stagger and toe. Thanks again. Joe
Click to expand...

As flattop points out usually tick more nose however on such a big track it should be fine, the other changes will help roll speed and it still should handle good.
Gearing is very important on a big track like that ( I point this out because back when you were running most everyone were running smaller front drivers was Norm compared to now ), is it a Clone Motor and what gearing combo are you on ?
 
RP- Yes, akra adult clone. Tried a 16 front from guesstimating old habits, ended up having to drop to a 61 rear by feature. Still ended up just above where i wanted to be. Did not have a 17 front in my box. Got one ordered, and will probably be going 17-64/65 next time. Maybe even an 18 if things line up. Track has potential to be flatfoot, but a little dust on entry just about mandates a burp in throttle to set the front.
 
I think you'll find once you got everything all tweaked out and your Maximizing Momentum you'll be ordering a 18 driver, we use 17 & 18 drivers here on a 1/5th mile track BUT it grips up real well.

Good Luck !!
 
Alright, so I did some more tuning. New setup is:
56.2% Left
46.5% Nose
60.8% Cross
-2.75 RF
+0.50 LF
1 1/2" Front stagger
Still at 1" rear stagger
39.25 Rear track
Seat is at 10"

Ran really well Saturday. Really good center off. Just couldn't enter the corner as hard as some, or the rear would try step out. I think my tires are still a tick on the too hard side, but they were much closer than the first outing. Trying not to over soften and shred them.

So, aside from tires, should I pull a little weight off the nose? Little less LF camber maybe? More bite in the RR? It is only a minor problem. Just looking for the best fix. Thanks guys.
 
Flattop- Thanks for the advice. The left % was the biggest change from the previous setup and I feel it helped tremendously. On the original 55.2%, the kart was loose in, then tight/binding in the center to exit. Overheating also. With the 56.2% left, still a tad loose in, but rolling the center/exit very well. Temps stayed good this time too.

RP- 5 LS, 6RS
I can see how lowering the seat a touch may help also. Looking at pictures now, I can see i am sitting up a little bit higher than most on the track. Seat was setup before for 1/8 mile wet to tacky tracks. Good catch. Will lowering the seat have any negative consequences from center off. It will just reduce a little transfer correct?
 
greenmeansgo said:
Flattop- Thanks for the advice. The left % was the biggest change from the previous setup and I feel it helped tremendously. On the original 55.2%, the kart was loose in, then tight/binding in the center to exit. Overheating also. With the 56.2% left, still a tad loose in, but rolling the center/exit very well. Temps stayed good this time too.

RP- 5 LS, 6RS
I can see how lowering the seat a touch may help also. Looking at pictures now, I can see i am sitting up a little bit higher than most on the track. Seat was setup before for 1/8 mile wet to tacky tracks. Good catch. Will lowering the seat have any negative consequences from center off. It will just reduce a little transfer correct?
Click to expand...

No lowering the seat should not hurt center off in fact if it settles the tick loose in it will HELP it off, Since you feel your tires are little hard yet might want to test using only 1/2 lb air split instead of a full lb.

Good Luck !!
 
Thank y'all. I will make some slight tweaks and let y'all know how she does in two weeks. Tires should be a little better again this time also.
 
Alright. Update time. So this past race they did the track up real well. Mandatory roll in, little bit of calcium, and moved the groove up in the straight to use a little more of the track and make the corner transitions a much better arc. Very big and wide track. I believe the top 2 or 3 were flat footing now. Lap times dropped about 1.25 seconds from previous races, and I ended up about 0.20 to 0.30 off of some fast guys.

On the first two previous races, I was battling loose in, but great center off. Was just as fast as everyone, just a tick loose in. Also was till figuring tires out. As RP suggested, my seat was a little high, so I dropped it to 9.25 and rescaled. Here are the new numbers:

Front-46.6%
Left-56.6%
Cross-60.4%
-2.75 RF
0.50 LF (bubble fell out of my camber gauge and broke, so cant change that till I get a new one)
1 1/2" front stagger
1" rear stagger
39.25 rear track
9.25" seat back

So, with the track being as good as it was, my loose in was gone( Either from the changes, or the fact there wasnt much dust this time). Kart was good in but then a tick loose just before apex and through the apex. Kart was good on exit, but the loose center slightly affected exit speed.
Was not bad though, ran 3rd out of 8, but top 2 were walking the dog. When all was said and done, I was about .20 a lap off of them.

Am I thinking right to want to add some more left? Maybe loose a 1/4" of stagger?

My gut tells me my tires are probably my issue. I did not do very much internal work to them, and only used what I already had, damn budget racing. So one set I rolled 1 1/2oz grape RS, 1oz LS, then worked them down to about 48-50 with grape, then just been putting the black sand to them. The other set, I rolled 2oz grape/SQS RS, 1 1/2oz LS, got them to 50-52 duro, then worked the black sand. I did not want to overprep and then shred, because I dont have a lot of experience with internal prepping. Back to back qualifying this last race, the grape set ran .15 faster than the grape/sqs set. The grape set has more softening from the outside than the grape/sqs set. Any recommendations for these tires? Also, when I buy another set, what do you think I should start them with? Will be using any track tac prep.

Sorry for the journal entry :) And thanks for the help.
 
Sounds like you are getting there.
I think it's in your tires.
It's about to get warm so grape inside might not be so good in new tires.
If your going with track tac best to call them .
 
Ok, so we got this thing hooking for the most part. Stole me a win, and running up front consistently on a local track, 4-10ish in class. Thanks for yall's help.

Quick question though. Seen this pop up in a thread a while back. My RF caster block is in the front position. Ive seen a lot of people say to run it in the rear position and it creates more bite up front. Way back in the day, if I went to a big race with lots of entries, this phenon would always have a slight to decent push on entry to middle. Should I be running this kart with the block in the rear position?
 
On a 1/4 mile track, I don't know if you'll see a difference moving the block back. But with saying that we've always ran ours in the back hole with the Phenom's and Triton no matter the size of the track.
Next time your at the track, move the block back and try it, if you don't like it, you can always put it back to the front.
 
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