'14 AGM 1SS/1LE Track build [COTW 11/17/14]

[X25]

Originally Posted by BaylorCamaro

Hey X, I'm looking to revamp my suspension. I'm on 100% stock bushings, really the only suspension I've changed out is the Sways and end links. Couple of questions, how do you like the solid sub frame bushings? I was looking at ADM's billet solid sub frame bushings. My biggest concern is rid quality when I'm not on the track. Not my daily but still do go to car meets on the weekends. Also I'm not familiar with Pegasus suspension components, how are you liking them? Finally, have you only done your sub frame, and trailing arm bushings? My biggest issue right now is putting power down on corner exit..

I have originally used polyurethane bushings, but since then I have switched to Z/28 suspension package, which comes with all the suspension control arms which have the upgraded bushings. The OEM bushings have a metal shell, which keeps things in place and makes the bushings very durable, not to mention the higher durability of rubber over polyurethane to start with. If you will keep the 1LE parts, I'd highly recommend you take a look at inserts, too. People think inserts are a compromise, and that complete replacement would be better, but I beg to differ. The OEM bushing is already a much better design, and it just needs more stiffness, something deliberately removed from the bushing by OEM by way of those big gaps that you can 'fill back' : )

Regarding subframe solid bushings: They are all more or less the same design. PegasusCNC provides the very same product, actually with more CNC work on it (holes drilled around) to reduce weight. As long as it doesn't fail, it should perform the same, and as a bonus, it has a better pricing.

There was no hit on NVH with the solid subframe bushings. You should keep in mind many cars (including GM's own) come from the factory with solid bushings. The parts that make noise (tires, differential, etc.) are already isolated with their own bushings. Actually, my diff cooler caused the biggest increase in NVH among all mods, at least until the fluid warms up

[BaylorCamaro]

Originally Posted by X25

If you will keep the 1LE parts, I'd highly recommend you take a look at inserts, too.

I actually have a ZL1, but I imagine the OEM bushings between the ZL1 and 1LE are similar. I'm glad to hear NVH is minimal by going to a solid metal sub frame bushing. I would have thought that moving to an aluminum "bushing" with zero give would have caused noticeable NVH.

[X25]

Originally Posted by BaylorCamaro

I actually have a ZL1, but I imagine the OEM bushings between the ZL1 and 1LE are similar. I'm glad to hear NVH is minimal by going to a solid metal sub frame bushing. I would have thought that moving to an aluminum "bushing" with zero give would have caused noticeable NVH.

Oops, sorry, I actually knew you had ZL1. I am yet to try it all at the track. I just tried to see if I can cause wheel hop since they say it helps a lot, and well, I was able to easily induce wheel hop, so no, solid bushings are not the cure for that :P

[Stephen12ZL1]

coincidence?

[h018871]

Hey Baylor, what do you mean by having problems exiting corners?
Wheel hop
Rear kicking out
Single wheel spin

[X25]

Originally Posted by Stephen12ZL1

coincidence?

Haha

It would be nice to have a good chunk more money right now; I could think of a project or two to use the funds on... : )

[X25]

Originally Posted by h018871

Hey Baylor, what do you mean by having problems exiting corners?
Wheel hop
Rear kicking out
Single wheel spin

I'm guessing he just can't put the power down early enough. That's been my problem for sure.

[red_riot]

Originally Posted by X25

I'm guessing he just can't put the power down early enough. That's been my problem for sure.

i am not expert like you guys so please bare with me if this is a stupid question, but is this result of having "too much" torque?

reason i ask is because i was watching the z28/gt350r head to head, and one of the huge advantages the gt350r had over the z28 was how early and effectively the gt350 put down power out of corners. randy pointed out how the z28 struggled to put down power coming out of corners compared to the gt350r, and i wondered if the boatloads of torque was a curse in this situation.

[X25]

Originally Posted by red_riot

i am not expert like you guys so please bare with me if this is a stupid question, but is this result of having "too much" torque?

reason i ask is because i was watching the z28/gt350r head to head, and one of the huge advantages the gt350r had over the z28 was how early and effectively the gt350 put down power out of corners. randy pointed out how the z28 struggled to put down power coming out of corners compared to the gt350r, and i wondered if the boatloads of torque was a curse in this situation.

I'm not an expert, but I don't think torque is ever a problem as long as you can modulate it smoothly, and the final torque at the wheels of these cars during a hot lap would be similar anyway:

• Assuming LS7 has a redline of 7000 RPM, and GT350R has a redline of 8200RPM, for each car, transmission ratios will be optimized so that you can make the most out of these engines. As shown by the dyno results in the same article, each engine makes about the same peak horsepower, but in different ways.
• GT350R has lower torque, but makes up for it with a higher RPM range. In order to capitalize on this, and make most out of it, Ford has to shorten the gear ratios (either individually, or by using a much shorter final ratio). This will multiply the torque at the wheels enough to just about match what Z28 has at the wheels with its taller gearing.
• Long story short, LS7 will have taller gearing, which will effectively reduce its torque multiplication at the wheels, whereas GT350R will make up for its lack of torque with shorter gearing. At the end, I doubt the lack of traction by corner exit is caused by too much torque since they will be at similar torque levels at corner exit (imagine LS7 exiting corner at 5000 RPM, while GT350R will be at 6500 RPM with a significantly shorter gear, boosting its overall torque ath the wheels).
• There are many reasons why this might have happened. Perhaps their long term Z/28 is not at its prime anymore (tires, alignment). Perhaps much lighter wheels and lower overall weight allow the magna ride to be much softer at the corner exit, which boosts traction significantly (ask a drag racer which suspension works best for traction). DSSV shocks are excellent, but they can never get as soft as a magna ride shock when needed.

It will sound crazy, but the dyno data in that magazine actually shows that 11-year-old LS7 is a better engine, at least for my taste. For the same peak power, I'd take the engine with more overall torque any day, since it means lower number of gear changes necessary, and less heat generation due to lower average RPMs.

There is one big advantage to lower average torque: it's easier on the drivetrain and transmission. This allowed Ford to install a lighter duty transmission on the GT350R, and no matter what you do, it will be a faster shifter than the Tremec 6060. As Randy Pobst once mentioned regarding our transmission: "...it's very precise, but you can't rush it."

[Pushrod Pete]

Gooood stuff. Thanks x25.


Btw this thread is amazing

[BaylorCamaro]

Originally Posted by h018871

Hey Baylor, what do you mean by having problems exiting corners?
Wheel hop
Rear kicking out
Single wheel spin

Originally Posted by X25

I'm guessing he just can't put the power down early enough. That's been my problem for sure.

X has it right. I'm having issues being able to get on the throttle early enough. Of course the metric I'm using is when I'm chasing C7's and other light cars that have a great suspension set ups. Running cars down on straight aways or in braking zones is rarely my issue, it's always corner exit. Damn Porsche's

[X25]

Originally Posted by Pushrod Pete

Gooood stuff. Thanks x25.


Btw this thread is amazing

Glad you enjoyed it : )

Originally Posted by BaylorCamaro

X has it right. I'm having issues being able to get on the throttle early enough. Of course the metric I'm using is when I'm chasing C7's and other light cars that have a great suspension set ups. Running cars down on straight aways or in braking zones is rarely my issue, it's always corner exit. Damn Porsche's

I have not yet tried my solid subframe bushings or the solid bushing at the knuckle at the track, so we'll see about that. I did, however, change my differential to address the traction issue. I don't know how the OEM ZL1 differential fares (and I'm sure it's a beefier unit), but the OEM SS differential literally 'opened-up', not locking when needed. The helical differential I installed should always lock (as long as I do not screw up the fluid) when needed, and should not lose its locking capability since it is now gear-driven.

There are so many things that contribute to better traction off the corner: Soft/compliant suspension (ZL1's magna ride would provide it, but stiff sway bars might impede a bit), good differential, good alignment (don't recommend too much toe; you can't get too much negative rear camber on these cars), good weight on rear tires (don't replace your battery with a Li-Ion :P), less body flex, less overall weight, aero, etc. Himm perhaps I should post to your main thread about this issue, too : )

[X25]

Got the alignment done!


I was maxed out at around -1.6 camber at the rears. To keep the balance, I decided to limit the fronts at -2.7 (which creeped to -2.8 when we fixed rear toes). I used to have about 5.8 degrees caster. I took the opportunity to increase it to 6.6, too.


It's ready for track! The first one I see is on 2/20 (if it doesn't get canceled).

[Dropspeed]

Originally Posted by BaylorCamaro

X has it right. I'm having issues being able to get on the throttle early enough. Of course the metric I'm using is when I'm chasing C7's and other light cars that have a great suspension set ups. Running cars down on straight aways or in braking zones is rarely my issue, it's always corner exit. Damn Porsche's

I had a long conversation with a close friend (that works at some small company called SVO or maybe SVteam of something ) about power delivery. Specifically about the Z/28 (they own one) and the GT350. As mentioned even Randy Poubst notices that the Z/28 twitched or dances for a moment before accelerating from the corner. The team at Furd SUT believes it is a combo of weight over the rear wheels, Susp and torque as a combination. There was way more to the discussion, but it is a know issue with the Camaro and power delivery on exit.