Killercanary what kinda suspension you have

[Slow5.0]

I think I find out why my e.t. is bad
In stock form I run 15.1@89 (all stock except flowmasters ,CAI ,180* T and hypertech chip)
Than I put 3.73s,H-pipe, MAX speed lowering 2" springs and 255/45/17s GSC tires on back, than I run 14.8@95
I think my problem is suspension and little bit bigger 255/45/17 tires
#1 Suspension because I can't transwer weight to rear with lowered springs, my car all time lay more on front and on launch rear end goes up(have to go little bit down but isn't)
#2 GSC tires because in stock I run on factory goodyear ZR45 (245/45/17) than I change to goodyear GSC (255/45/17)
Overall Diameter in 245/45s are 25.7" in 255/45s are 26.0" so bigger tires need more to roll down I mean it take time BUT I get better mph with bigger tires
I know those 255/45s are not that much bigger but still
SO question for Paul (Killercanary) what kinda suspension you use (what kinda you use before and now)
I have like you Convertible ,heavy a$$ car so meybe we have to use different kinda set up than coupe

 

[Killercanary]

When I went 12.7 at 107 I had a completely stock suspension, subrframe connectors, and the hooker car bar. Now, I have Global West LCA's and I replaced the axle side bushing on the UCA.

There is a reason I still sport the 4X4 look... weight transfer!!!

 

[Slow5.0]

Yesterday one guy tell me I have to use 4 cilynder springs on rear, what that mean , meybe I have to use rear springs from 87-93 4 cilynder Mustang ????

 

[Killercanary]

4 cyl springs go on the front, not the rear. If you put them on the rear it will squat way too much. I've heard of throwing V6 springs on verts too. We tried the 4 cyl springs on my dad's car and it didn't help at all. If you want to learn a lot about drag suspension look up Kevin$ on the corral, he has a lot of useful info to offer.

 

[Slow5.0]

Ok, here is one pisc how my Stang looks like with 2" drop all way around ay track

 

[Slow5.0]

What you guys think about this new set of upper/lower control arms on Ebay $145 + shipping

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33583&item=2467286101

 

[chaos254]

why not check out coilovers? gmkillr has them on his car and if I remember correctly, he was pulling 1.6x's at the track.

 

[randomjoker]

Seth how much does your car actually weigh?

 

[Slow5.0]

Seth how much does your car actually weigh?

Race weight 3720lb , why?

 

[randomjoker]

Race weight 3720lb , why?

Just to put a picture in my head..

 

[94GTLaserRC]

why not check out coilovers? gmkillr has them on his car and if I remember correctly, he was pulling 1.6x's at the track.

can someone explain briefly how things like LCA's, subframes, and coilovers help in your 1/4 times?

RC

 

[HRT11]

you wiegh 3750 !!!!!
thats wherethe trouble is

 

[Killercanary]

can someone explain briefly how things like LCA's, subframes, and coilovers help in your 1/4 times?

RC

Briefly... yeh right...

Subframe helps to reduce chassis fles. Our cars are a unibody construction, and we have basically 2 frames that are tied together with sheet metal, there is a forward and rear frame... hence the name "subframe". The point of subframe connectors is to reinforce the are between the two subframes and amke them stronger. By doing so the chassis flexs less, and is able to put more power into actually moving the car than twisting it. It also helps in terms oif weight transfer as the car is less likely to "buckle" in the middle on launch.

LCA's help because the factory units are made with rubber bushings and "stamped steel". Both of these flex under hard acceleration and turning. There is a LOT of force going on in the LCA as the rear end of the car tries to literally push the LCA through the floor towards the front of the car, the UCA experiences a reverse motion and is trying to be "pulled" out of the car from front to back. This distortion, during drag racing, can lead to a change in pinion angle where the front of the rear end is pitched violently upward on its axis. Basically the snout where the driveshaft and rear end yoke connect wants to go into the trunk, and the differential cover wants to go to the ground. This is what is refered to as axle wind up. This is experienced on the track typically in cars that will plant the tires for a second and then they let go as the rear end returns begins to unwind. Its best to have a negative pinion angle of a few degrees when drag racing (anywhwere from 2-4* in general) so that when the rear end does wind up it doesn't result in a large positive angle because this is where trouble begins. An ideal setup included LCAs and double adjustble uppers so that you can actually adjust pinion angle. I have the stockers so I'm stuck with a 0* to -1* pinion angle in my car. Lowered cars typically result in a POSITIVE pinion angle as the angle between the DS and the pinion yoke decreases leading to a greater chance of a positive angle occuring under acceleration.


Coil-overs do a few things. The reduce weight because the coil-over setup uses a smaller spring than the stockers, and they allow for adjustability in terms of ride height with the turn of a spring perch. They do put a LOT of stress on the strut towers so 4 bolt caster camber plates are a must have with them. Also, as in Rob's case (GMKILLR) he has "drag springs" in his coilovers, typically these are a LONG front spring that is sort of soft and compressed. This spring has a great deal of potential energy stored in it so that at launch when the weight starts to come off the nose and get transfered to the rear, the springs "unwind" and push the nose of the car up. Strangely enough, I've watched Rob's car and the things doesn't do much of any visible weight transfer, but he was getting LOW 1.7's on Nitto DR's with that setup.

In an ideal situation you want the rear to squat very little (which is my big problem as my rear squats BAD), the rear end to not wind up, a negative pinion angle, the front end to come up enough to sufficiently put weight over the rear drive wheels yet come down after doing so as to improve aerodynamics as you continue down the track.

Lesson over..... was that brief enough?

Seth50- you get what you pay for in terms of LCA/UCA's. My GW LCAs were a fortune. I'd recommend you go with a tubular design over a "box" on as the tubular design resist flexing more. In our heavy cars we need the strongest stuf we can get.

P.S.- I spoke with Rob (GMKILLR) last night and he is almost done with his house so he should be getting a new computer here in a few weeks and be back on with us.

 

[Killercanary]

Here's a pic of me launching. The front end is up which is good (I think I can fit my head in the driverside wheel well!) and in this pick the rear doesn't appear to be squating too much, but it does.

 

[stangboy]

Killer, that launch looks really good. Was that on one of your 12 second passes? I think my weight-jacker LCAs played a part in me snapping and axle at the track on drag radials. The thing I like about my LCAs(Granitelli Motorsport adjustable weight jacker LCAs) is I can adjust the ride height and the length of the arm which adjust the pinion angle. Now, I have no idea what angle its at right now, but I think my car launches pretty good. I'm just a little scared to launch too hard because I cant afford to snap another axle and I can't afford to upgrade to a 31 spline setup right now.

 

[Killercanary]

Thanks! Yes, that was a 12.3-12.4 run (it was from when I was at Cecil and every pass that day was in that range).

Definitely check your pinion angle, a checker is only a few bucks, heck I think I saw them at lowes. I too was afraid of breaking something, so before I did I bit the bullit and bought a set of superior 31 spline axles and an eaton posi.

 

[swingline]

Paul are you wearing a helmet?

 

[GTJake]

Yeah he is. You have to at most every track.

Jake

 

[swingline]

I knew you had to but it looks wierd as hell. Like a eagle or something?

 

[Slow5.0]

Seth50- you get what you pay for in terms of LCA/UCA's. My GW LCAs were a fortune. I'd recommend you go with a tubular design over a "box" on as the tubular design resist flexing more. In our heavy cars we need the strongest stuf we can get.

Do you have any pics , I have no idea how tubular LCA/UCA looks like