mallett435

I know the kit part number 23336064 is for non-MRC cars. It includes sway bars, shocks, LCA, etc... I've called around and no one seems to have individual part numbers.

I have a 2014 Z51 MRC. I'm trying to see if just the sway bars and LCAs are improved for track over my stock setup. A GM sales rep told me the sway bars and LCAs in this package are the exact same as my current stock MRC sway bars/LCAs. I watched a C7 non MRC with T1 suspension drop 6 seconds off VIR track time vs stock Z51 MRC car with the same driver, same day, same lines, same tires, etc... I can't imagine how that can be correct that the only difference to my car are the T1 shocks. I'd like to buy the kit minus the shocks, but I'm sure GM would say they only work as a complete kit.

Does anyone know the individual part numbers? Are the T1 sway bars adjustable? Can you buy them separately? Thanks in advance!

axr6

T1 spec cars run on slick racing tires. Are you sure that the one that you witnessed had the same tires as the Z51? The slicks are probably good for 3+ seconds per lap over the stock tires.

mallett435

The Z51 T1 suspension car did have slicks. However, the T1 suspension definitely stiffens the car compared to mine. My car is extremely soft in off camber cornering. I run PTM in Race Mode. T1 sway bars IF different than mine would maintain my warranty and hopefully firm up the suspension.

axr6

I'd suggest that most of the lap time differences were due to the slicks. As to the suspension softness; yes, particularly the stock sways are kind of soft. Particularly the front bar.

I have gone through all the stock model swaybar variations and finally purchased the aFe bars which are significantly stiffer than the stiffest stock bar. With the stock bars I did not like the softness at turn-in. With the double adjustable front aFe bars that softness is gone, even when left in the softer position. I have not even tried the stiffer position as the soft one is sufficient for me. The triple adjustable rear bars are in the mid position. With that adjustment, I get responsive transitions in canyon driving. For track it would worth exploring the stiffest settings.

X25

The sway bars and shocks are different part number. The LCAs have the same part number stamped on them as stock, but they actually come with different bushings on them.

Regarding use of slicks: The MRC cars will feel too soft when used with tires that provide better traction than stock. In your case, I'd first recommend that you switch to FE3 springs, which are what T1 kit is also designed for. FE3 is much stiffer than your FE4, and should help immensely.That said, your MRC shocks will then be underdamped, and that will hurt your performance. There is an aftermarket device, provided by DSC motorsports, which could help you tune the MRC to match the stiffer springs.

mallett435

Thanks for your info! Very helpful! I noticed on another that rear sway t1 bar is the same as the z51 mrc bar but the front is different. It sounds like aftermarket sway bars are the best option. I will research DSC.

mallett435

Yea, I run Toyo R888s 245/285 on stock spare wheels. 3 seconds is probably accurate with slicks. I also have the gm spec track alignment. As you said, stickier tires on stock bars makes the issue worse. It flexes pretty bad through hog pen and nascar bend sections of VIR.

Your bars sound like a great option. Thanks!

X25

Just checked the T1 part numbers: Front 20959434 (which didn't return the right part when I looked up) and rear 22936510. Indeed, rear bar seems to be FE4 stock bar!

mallett435

Nice find! Ironic that these gm parts dealers can't find the part numbers. The front bar part shows up online titled as GM Shaft.

For the price, I'm leaning towards aftermarket as a more tested setup for an MRC Z51. Disappointing GM has no interest in providing track suspension upgrades for MRC cars, but they promote it as the better track car.

X25

The rear bar shows at $70, the front part number showed up a shaft and it's $360; I don't think the part number shows the right part. If we could find it, $70 front bar for 40% increase in stiffness (compared to FE3?) would be a great bar to try out

X25

Until we learn the spring rates of various C7 stock suspension spring rates, it's hard to consider any of the rates you list above

X25

Perhaps we should ask Tadge : )

ssidekickbp

I understand the value of the T1 suspension on the track, but is it livable on the street as well????

Those with it please chime in if you've driven it on the street as wel.

X25

There are those who even think stock Z51 (FE3) is unbearable for the street, so this is not an easy question to answer. In my opinion, it is pretty similar to stock suspension, except when the surface gets very uneven (like train tracks, etc.), where you feel the additional harshness. It uses the same springs as FE3, and the sways are about 40% stiffer, while the stiffer bushings might also have a marginal impact, but probably not that much noticable. I don't think it would be harsher than a car with, say, LG sway bars, which are also significantly stiffer than stock bars.

rsalco

I had full T1 suspension in my C6Z; control arms w/delrin bushings, sway bars, springs, shocks. The complete package in place of the factory Z07. Firstly, I would not recommend mixing & matching T1 bits with stock ones; it is engineered as a balanced package. And as a complete package the track handling is outstanding. The car becomes very composed and easy to drive fast on a road course. Even with street PSS rubber; on slicks it's as quick or quicker than anything else you'll run across at HPDE's or track days.

Driven on the street my experience has been that it's not unduly harsh or choppy, really, not degraded in ride quality compared to the Z07 suspension. Compared to a Z51 car, yes definitely stiffer. My previous car was a Z51 C6 with the T1 installed.

In any case, a notable difference is noise and vibration. The T1 takes all the compliance out of the attachment points so you do get clanks and bangs along with some road surface vibration. I don't find it objectionable but others may have a different view. I've driven the car from my home in Syracuse to Watkins Glen multiple times, a distance of 100 miles or so, and found the ride quality and comfort to be acceptable.

Good luck with your upgrades.

mustclime

Interesting thread, One thing you guys may be missing is I am pretty sure the MRC suspension has softer springs the the stock z51 suspension. Thats why the T1 is for the non MRC suspensions. If you look at the part numbers of the springs, they seem to have different numbers. If you think about it, how would the MRC suspension be able to provide a softer ride if the springs were as/more stiff of the stock z51 without MRC with just a difference in the shock damping? ......I learned early on that tires set you spring rates, and your spring rates set you damping requirements. MRC allows GM increase compression damping when needed and that acts as a increase in spring rates. In no way would MRC be able to make a spring feel "softer" by changes in damping.

Long/ short of it, we need one of you guys with deep pockets to pickup some different springs and try them out. By my math, the z06-07 should have the stiffest spring rates( you know, the grippier the tires, the stiffer the springs).

rsalco

The complete T1 includes race shocks. It is for non-MRC cars because the MRC shocks have sensors that provide data to the ECU and MRC control module. To avoid error messages and performance restrictions in MRC cars running non-MRC shocks you must either use SIMS [pre-'11 cars] or untoggle the MRC function in the ECU. When you do that you lose the different levels of stability control, unless you are able to alter those parameters in the ECU code. I am not aware of anyone able to do that, but there may be a race tuner out there who can. I didn't bother with it, preferring to go 'old school' regarding the nannies.

RapidC84B