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Old 05-29-2013, 09:28 PM   #3856
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Hey guys, my car has been really good for me but im struggling with something as of late. The track conditions I have been running lately would be medium to med-high grip if prepped right, and Im having an issue with corner exit with my rear end breaking loose. could be my fault and need to work on my throttle control, but I was wondering if anyone had an slight changes I can try without changing my setup to much. I just went from -1.5 to -2 degrees of camber in the rear to try and help. Would longer rear links help alos? Thank you
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Old 05-29-2013, 10:07 PM   #3857
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Originally Posted by Tekin Prodigy View Post
Hey guys, my car has been really good for me but im struggling with something as of late. The track conditions I have been running lately would be medium to med-high grip if prepped right, and Im having an issue with corner exit with my rear end breaking loose. could be my fault and need to work on my throttle control, but I was wondering if anyone had an slight changes I can try without changing my setup to much. I just went from -1.5 to -2 degrees of camber in the rear to try and help. Would longer rear links help alos? Thank you
I had the same problem until I took the rear swaybar off.

I drilled another hole in the rear arms 3mm closer to the middle for the bottom shock mounting point so I could make the rear even softer.

Last edited by edhchoe; 05-29-2013 at 10:35 PM.
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Old 05-29-2013, 10:39 PM   #3858
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Just visually, I think the 2 hole option arms would give a similar effect on the inside hole for those not wanting to drill arms...
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Old 05-29-2013, 10:54 PM   #3859
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Originally Posted by Tekin Prodigy View Post
Hey guys, my car has been really good for me but im struggling with something as of late. The track conditions I have been running lately would be medium to med-high grip if prepped right, and Im having an issue with corner exit with my rear end breaking loose. could be my fault and need to work on my throttle control, but I was wondering if anyone had any slight changes I can try without changing my setup tpo much. I just went from -1.5 to -2 degrees of camber in the rear to try and help. Would longer rear links help also? Thank you
Most of the time when this happens with my car it's because it's transitioning to the rear to quickly when I start to apply power, and causing too much body roll, or not "returning to center" quick enough. A slightly heavier oil in the rear can help, or a slightly stiffer spring. If it's excessive roll that's the problem a shorter rear link can help.

That said, it could be over rotation due to too stiff of a spring. Without setup details it's hard to know which. Look at Martin Crisp's setup app, many times the advice is to do "this change", or the exact opposite of "this change".

IOW, as the above poster mentioned, a softer rear spring worked for them, but it could also be too soft. More detail is needed.

E
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Old 05-29-2013, 10:59 PM   #3860
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Man I tried tons of stuff...but the stuff that did not stick was the following:

1)Medium front roll centers...the car seemed to push without Lows on the front
2)Gear Diff with 2.5 Million...the car was better with the spool
3)4 Deg caster blocks...the car did not turn in very well without 6's on (which seems a bit counter intuitive to me)
4) short camber links all around...made the car really twitchy and harder to drive
5) 2.5 springs front and rear...felt like I needed the car to roll a bit more based on the hardness of the tires
6) Graphite Arms both front and rear...made the car feel numb, this was a very bad idea from the start
7) Less droop...I needed to move more weight around the car to less droop did not help my situation at all

I needed steering so a thinner front bar would have made things worse...I steered clear of that one.

Overall the car was pretty good...I was surprised that I could feel the shimmed up steering rack...but it did seem to make the steering feel a bit more direct
I agree with 99% of what's said here, but I'm confused by one point. 2.5s didn't provide enough roll, but a thinner bar would have made things worse. Was it roll that was needed or was it initial steering provided by the stiffer bar and weight on the tires that was needed?

Not sure if you saw the setup I ran, and if it was due to my running open class that made my recipe work, but my car felt really good. I would highly suggest any of the open guys to give it a shot. If I need to repost, LMK.
E
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Old 05-30-2013, 07:51 AM   #3861
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I'm very interested in getting a T4.

But I will be racing it with foams and a front differential due to the nature of the track. (carpet, very small technical track, a spool isnt suited to it) so I have a few questions so I am 99.9% sure I will need additional parts from the start.

1) Can anyone tell me if 30mm wide foams will fit? (no big deal if they do not).

2) Can anyone confirm the part numbers needed for a front diff (and I am assuming I will need a packet of driveshaft sleeves too?)

I think the #s are

304900 and 305241

3) Are there any particular build tips not mentioned in the manual that are worth noting?

Many thanks!
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Old 05-30-2013, 07:53 AM   #3862
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Originally Posted by erchn View Post
I agree with 99% of what's said here, but I'm confused by one point. 2.5s didn't provide enough roll, but a thinner bar would have made things worse. Was it roll that was needed or was it initial steering provided by the stiffer bar and weight on the tires that was needed?

Not sure if you saw the setup I ran, and if it was due to my running open class that made my recipe work, but my car felt really good. I would highly suggest any of the open guys to give it a shot. If I need to repost, LMK.
E
I ended up running 2.3s...but I started with 2.5s. I believe I got the roll I needed with the 2.3s. 2.5s just felt too stiff in mod.

A thinner bar in the front would have helped mid and exit...but I needed more initial turn in. After talking to Paul we both agreed that a thinner bar was probably not the right approach.

I have not seen your setup but I am interested to see how it differed.
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Old 05-30-2013, 09:19 AM   #3863
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Default Narrowing front track!!

Hi

What are the main differences in handling between narrowing the front wheel track by using thinner wheel hexes or using smaller washers on the wishbone mounts?
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Old 05-30-2013, 09:58 AM   #3864
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Originally Posted by artwork View Post
I ended up running 2.3s...but I started with 2.5s. I believe I got the roll I needed with the 2.3s. 2.5s just felt too stiff in mod.

A thinner bar in the front would have helped mid and exit...but I needed more initial turn in. After talking to Paul we both agreed that a thinner bar was probably not the right approach.

I have not seen your setup but I am interested to see how it differed.
Gotchya, thanks.

I think this setup worked well because I got the roll I wanted by running a very light or no bar. I'd like to try lower roll centers though, I'll give it a shot next time out.

For reference, the spring chart here shows the spring stiffness comparison, it's a pretty big jump to Red springs from the standard 2.5 or 2.3.
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Last edited by erchn; 05-30-2013 at 10:04 AM. Reason: Add link to spring chart.
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Old 05-30-2013, 10:01 AM   #3865
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Hi

What are the main differences in handling between narrowing the front wheel track by using thinner wheel hexes or using smaller washers on the wishbone mounts?
For me, narrowing at the arm holders makes the car more twitchy off center, responds more quickly. I usually tune the other direction, wider to calm the car down, if anything. It should technically make the front-end stiffer as well, as the shock will be more upright.

Narrower hexes can make the car react a bit quicker, and feel a little less stable.
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Old 05-30-2013, 03:14 PM   #3866
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What are your guys opinion on the RSD spring vs. the Spec-R spring vs. the Xray springs? Is there a good reason to go w/ one over another? RSD carries the spec R kit at half the price of their own springs. Just curious what you guys think.

Thanks
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Old 05-30-2013, 03:40 PM   #3867
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The Spec R Springs are too long for the XRAY T4. They are great springs though.
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Old 05-30-2013, 03:40 PM   #3868
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What are your guys opinion on the RSD spring vs. the Spec-R spring vs. the Xray springs? Is there a good reason to go w/ one over another? RSD carries the spec R kit at half the price of their own springs. Just curious what you guys think.

Thanks
Dave
I think no two springs are created equally. It's all about tuning options.
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Old 05-30-2013, 06:54 PM   #3869
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Originally Posted by CristianTabush View Post
Oil and piston tuning I find very useful in several different circumstances. They are far more important outdoors than indoors though.

1.Bumpy tracks: More pack helps out on tracks that are bumpy. It prevents the car from bottoming out over bumps and chassis slapping. This is much more important in mod than in stock.
Not normally one to post in here, but I read your top comment with interest, as I actually feel the opposite. On very bumpy tracks, I tend to reduce the pack as much as possible, as otherwise the car will 'skip' over the surface. This is especially the case, IMO, in mod, where your tending to hit the bumps harder. Thats why I tend to use 4hole pistons on my 411, but with a heavier oil.. this works in combination to reduce the pack (and hence make the high speed damping softer), whilst maintaining the body control (low speed damping). This is different to rebound mind, which is what tends to be set to help the tyres to stay in countact, again, IMO.

Quote:
2.Hot weather: For every 15 or so degrees of temperature, I tend to go up about 50cst. Here in Texas, we'll be racing in the winter in 40-50 degree weather and in the Summer we get to run in 100+ temps. That means that when it's cold I am at 300-350 and when it's hot I run around 450-500. If I don't compensate for the heat, the car has no damping.
Do agree with this, and same also goes for diff oils too... all the oils we use are susceptable to heat, and thin out at higher temps.

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3.High bite: While I have limited experience with the T4 on high bite, I have always run heavier oil in higher grip conditions. Typically more so in the front. Going to heavier oil in the front will mellow out the reaction time of the car and this makes it easier to drive.
Totally agree that a heavier oil helps to mellow the car, as it numbs the response time. Soft springs and heavy oil seems to work well on high grip, to help avoid traction roll, and make an easier to drive car.

Quote:
4.Pack can help in mid-to high speed transitions. Like chicanes.
Don't really agree with this, as I feel that it's more related to rebound setting, rather than the pack. Higher rebound will help to push the piston back down, and hence help to keep the tyres in contact with the ground.

Overall though, I do these days prefer a 4hole piston over a 3hole, certainly outdoors. My target there is to have a shock setup that is supple over the bumps, but still with a decent level of roll control... which comes down to tweaking the shocks to alter the high and low speed damping.

Regards
Ed
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Old 05-30-2013, 07:05 PM   #3870
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Tryhards post is the reason I post on here, to get everyone's opinion on a certain subject
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