GT Motoring Challenge Comp coilover review

KillerBee370

A little while ago I decided to try out the GT Motoring Challenge Comp coilovers on the killerbee. Since installation I have done a fair amount of regular and spirited street driving as well as one track day at Auto Club Speedway (video coming soon).

I'm no expert by any means on suspension or really how to properly relate to you in finite detail, the feedback that say, Michael Shumacher might give you however I will give you a seat of my pants style feedback.

I had a chance to drive the stock suspension for just a little while before going to much stiffer springs (Tanabe GF210) that were eventually matched up with a set of sway bars (Stillen).

First, some pics of the parts as they came out of the box:









Very clean and everything was well packed.

Now some install pics with a few things of minor note:


A pic showing the stock front shock with aftermarket drop spring intalled and the Challenge unit next to it:


The stocker in place (front):



The Challenge front in place:



Rear aftermarket spring and stock shock in place:


The rear challenge spring and shock in place:





Note: the stock rear shock has a nut welded into place:


The Challenge unit will require that you get a nut to replace the stock one:


Note: the stock front shock has brackets welded in place for brake lines etc. The Challenge unit does not however that's nothing that good ol fashion zip ties can't handle:



zip ties ftw! (no problems whatsoever with movement, clearance etc.)




So, you will need to improvise in a couple areas during install as shown above however, the installation process was very smooth.

I don't remember too much about how the stock suspension felt so I can't really make a fair comparison so I will speak to the differences between the Tanabe GF210 spring/stock shock setup VS. the Challenge coilover setup in this case.

Let me start by saying that the GF210's are a STIFF spring. I have two track days at Auto Club Speedway on them and together with the Stillen sways they were a force to be recon with with two major drawbacks... 1. no adjustable ride height and 2. no rebound dampening adjustment. All in all the setup performed well on the street and even better on the track in my opinion but definitely lacked finess when it came to any dampening. On the street it was just pure overkill. But I like that so it didn't bother me any

Okie dokie... so upon the Challenge going in I couldn't tell any big difference while driving on the street until I started to get a bit spirited. The suspension has a 12 way adjustable damper and I had it dead center. I found that to be a bit too slow on the rebound for my personal taste. Bear in mind that I still have the Stillen sways on (set to the stiffest setting). The Challenge springs are stiff. Are they as stiff as the Tanabe's? I don't know. They feel it but there is a bit more body roll from track pics of my vehicle so perhaps I just had not had the rebound set properly? I backed off a few clicks and it feels very stiff and snappy on spirited drives in turns however without pictures to compare, it's kind of hard to know for sure. I will say this, the car felt extremely tight at the track and I felt that with the improved dampening I could push harder in the corners than I could before with the Tanabe's without fishtailing out of turns. In that respect it made a noticable difference.

All in all I would say that I am very happy with the performance aspect of having these coilovers and the quality is solid. I am still learning to figure out a proper dampening setup but the car is so far above and beyond the bone stock setup that it's just ridiculous. I would say for the pricepoint of these coilovers, you really can't go wrong.

Adding a couple replacement nuts for the rear shock brackets and perhaps a few zip ties would serve this setup well but everything else is spot on.

KillerBee370

Reserved for video

res0zsfa

how much for these coilovers?

TreeSemdyZee

http://www.the370z.com/premium-membe...r-special.html

XwChriswX

Thank you KB for your review. Can you say what level of ride height you're rolling at on the street vs. on the track, or is it the same? Have you had any problems with the lowered ride height?


I'm pretty much sold on these as thanks to your review, and their color scheme suits me perfectly!

+1 rep for you sir.

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Bonnie - Stage 2, Audio build coming this fall!
R.I.P. Abby 3/29/10 - 3/30/14

KillerBee370

At first I had the ride height LOWER than I had with my Tanabe lowering springs and it was WAY too low! I literally could not get over a speed bump! So I took the car in to where I normally get my alignments done and they basically "fixed" the initial install and corrected the ride height. In the end it was about the same height that I had it at before or maybe an eighth of an inch lower.

Absolutely no problems at that point. I keep the same ride height on the street that I use on the track and it is lower than some would like however it doesn't really bother me too much. I still have to be very mindful of driveways and speedbumps and such however.

I will post up pics of the ride height soon.

XwChriswX

Awaiting pics

Exactly what was it they did to 'fix' the height? Did you have any problems with your springs and the ride height?

I'm having a problem with my Z squatting... I had to put in spring spacers to maintain the height, but I don't have as much compression space as I used to... I need to get it looked at again. I used eibach's by the way...

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Bonnie - Stage 2, Audio build coming this fall!
R.I.P. Abby 3/29/10 - 3/30/14

KillerBee370

The "fix" didn't have anything at all to do with the installation process. What happened was, MISTAKENLY I left out the rear bushings (see pic)



The bushing is there for a reason. I had left them out on the initial install and that was stupid. The springs don't seat properly and have a chance to move around a bit. Anyway, we put them back in and problem solved. Nissan developed these things for a reason.

XwChriswX

I think this is the culprit to my suspension problem as well!!!!!!! F'N-A!

I need to get it on a lift cause I think mine were left out after the install...

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Bonnie - Stage 2, Audio build coming this fall!
R.I.P. Abby 3/29/10 - 3/30/14

Cell

Rust proof??!?

Trips

Very nice write up Killer! I'm keeping these in mind for the near future, I've learned the Eibachs are good to a point, as hard as I'm pushing while doing Canyon runs I may need some Help, and these coilovers will definitely help. Thanks for taking the time to write it up and posting pics, also for giving us a honest opinion.

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KillerBee370

Yeah it sounds as though that may be the case. Double check it... you'll be glad you did.

G Fo12ce

Nice write up. Glad you noticed some better performance and stability at the track, seems like it made a difference.

For the price you pay GTM needs to provide those nuts. It's half-assed that you had to source your own. I mean what's it going to cost them? The suspension I had on my G35 (which has basically the same suspension design) came with them and the brake line mounts. You should definitely let them know.

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Nismo Suspension: New Owners Check Here!

vividracing

awesome review! great job!

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KillerBee370

Agreed.