My next rear suspension mod??

[buttonfly]

Ok so I a rolling a few ideas through my head, and I am tired of doing forum searches. Since I value everyones opinion here I would like to hear what some of you think. I am not changing a thing with my combo this year other than working on my tune, and most importantly suspension setup.
This is what we are working with boys. UMI double adjustable uppers, UMI solid lowers, and ATR rear sway bar. Stock springs, monroe shocks, all the add on bracing. It is a t-top car and I dont want to beat it up to bad, but I would like for a better showing when I do go to the track. With that being said I am leaving alot on the table with my 60 ft times.

I would like to work on the instant center of the car so I have thought about relocating the upper or lower control arm mounting locations.

I have thought about drag shocks, but I am afraid how it will feel driving it normal.

I have thought about just adding air bags.

I will say I have recently learned how to preload the suspension and I do have the pinion angle set to -2 right now. The car does leave straight, but I know I can do better. Something new for this year is hydroboost brakes and I can hold a good amount of boost with them. So tell me what you guys think and any input would be greatly appreciated. I also just changed to M/T drag radials this year as well.

also before we even go there with the H n R bar (we know its the best!) I'm looking to the best I can with what I've got, just looking to add a couple of ingredients.

Thanks Jason

 

[InHock]

air bags?

You are wanting to know about the same thing i need to know! I hope someone will help us figure out which way to go. I just ordered some MTdrag radials yesterday and was needing to know if air bags are also needed to or to get the shocks you have mentioned. I really believe we are going to be told to get air bags[at least one] for the car. I know someone will guide us in the right direction!

 

[WINDMILL]

contro; arms

if you have rubber bushings in the control arms i would go to 4 deg pinion angle. what boost are you leaving at? Also i forgot does you car squat (in the rear)when it leaves? if so you need air bags.

 

[charlief1]

Throw the monroes away and get some bilsteins. Don't even bother with the drag shocks unless you plan on using a trailer to and from the track. they aren't intended for the street and it will cause problems. Airbags are a good idea and aren't that expensive. Just remember to have seperate air lines to them.

 

[buttonfly]

if you have rubber bushings in the control arms i would go to 4 deg pinion angle. what boost are you leaving at? Also i forgot does you car squat (in the rear)when it leaves? if so you need air bags.

Well all the control arm bushings are poly. I fell like I can leave at about anything up to 15 psi right now. I really haven't had some nice days to really go out and test yet. Yes the car squats in the rear. Leaves straight, but squats.

So far the polls show air bags should be my next mod (nice and easy:biggrin: ) . I am still curious about changing the instant center on the car. I am really looking forward to hearing some feedback on relocating the control arms. I only want to make on mod on the rear suspension. Go out and test before and after so I can really see where this is going. I read a book by Dick Miller and everything made so much sense to me. He is a firm believer in relocating the upper or lower control arms in a 4link suspension like ours. I look forward to hearing some more!

 

[buttonfly]

Throw the monroes away and get some bilsteins. Don't even bother with the drag shocks unless you plan on using a trailer to and from the track. they aren't intended for the street and it will cause problems. Airbags are a good idea and aren't that expensive. Just remember to have seperate air lines to them.

Yes I thought the drag shocks would be a little over the top. I mean sometimes dont we all get just a little bit carried away. I need to pull in the reins sometimes and remember I have a street car I take to the track, not the other way around. I gather we have another air bag vote here as well. So what kind of PSI are you running on the Lh side vs. the Rh side? I mean I understand I am going to have to tweak it, but some rules of thumb would be nice. I agree about the shocks too, maybe momma will buy me some for my birthday!

 

[ttypewe4jim]

The bags are a cheap enough mod to do without really hurting the budget so I would say go for them. now with that said yor correct in saying the 60's are leaving alot on the table IMO you car should be able to 60 in the 1.5x range the way it sits right now... I see in your sig you where running old bfg dr's IMO rather then spending ALOT of money on relocating the control arms I would get a new set of mickey 275/60's and go from there. I think with a decent launch and a new set of tires you could get a 1.5x without much trouble.


hth

Edit I seen that you ordred new tires... I would make a trip to the track with the new tires and go from there I dont really think youll have much too much of a issue once you figure out the new tires. I agree with craig about setting the pinion angle around 4 deg angle.

 

[buttonfly]

The bags are a cheap enough mod to do without really hurting the budget so I would say go for them. now with that said yor correct in saying the 60's are leaving alot on the table IMO you car should be able to 60 in the 1.5x range the way it sits right now... I see in your sig you where running old bfg dr's IMO rather then spending ALOT of money on relocating the control arms I would get a new set of mickey 275/60's and go from there. I think with a decent launch and a new set of tires you could get a 1.5x without much trouble.


hth

Edit I seen that you ordred new tires... I would make a trip to the track with the new tires and go from there I dont really think youll have much too much of a issue once you figure out the new tires. I agree with craig about setting the pinion angle around 4 deg angle.

Alright I am really impressed with everyones input thus far! I did get some new M/T's on the way. Like I said I am just learning some vital things I have overlooked in the past. I have never concentrated soley on making the suspension work for me! I looked at some video's from the track last year, and I did notice a couple of things. The car does squat, and the car does appear to lean to the R/R. It is had to tell because of the angle my buddy was with the camera. I need to go out and test at the track and have him stand behind the car and shoot. I know if I get the 60's down everything else will fall into place. I have gained alot of confidence in my tune since the addition of the wideband, and that has helped. If I can get the suspension to work well enough for me I would like to ditch the .63 housing on the tuirbo and move to an .85, but that is down the road. I want to get my combo down in the low 11's and that is where I stop with this car. I would love to hear more so keep them ideas coming.

I would like input what some of you are running as far as air pressue in the bags.

Also lets talk about pinion angle. Why -4 degrees, seems like alot to me, but explain why. You guys have tried alot of things, and I am still learning.

 

[WINDMILL]

if the rear is squating the pinion angle is moving, you dont want the rear to squat at all. i just took vader87 car out the week ago and had 1.55 60f7 with his car leaving at 2# of boost with stock suspension parts(except bags). this is on 4 year old bfg drag radials and it spun the tires leaving. i know he had a little bit more motor than you. here the video
http://www.turbobuick.com/forums/turbo-videos-picture-library/276836-vader87s-11-040-run.html

also some people say it dont make a diff in pinion angle when the car squats but why does everyone wants the driver in the car to set the pinion angle then,, think about it...


and you never said what # of boost you had to leave to get the 1.77 60fts.

 

[buttonfly]

if the rear is squating the pinion angle is moving, you dont want the rear to squat at all. i just took vader87 car out the week ago and had 1.55 60f7 with his car leaving at 2# of boost with stock suspension parts(except bags). this is on 4 year old bfg drag radials and it spun the tires leaving. i know he had a little bit more motor than you. here the video
http://www.turbobuick.com/forums/turbo-videos-picture-library/276836-vader87s-11-040-run.html

also some people say it dont make a diff in pinion angle when the car squats but why does everyone wants the driver in the car to set the pinion angle then,, think about it...


and you never said what # of boost you had to leave to get the 1.77 60fts.

Ok all of this is very promising, and I think I am on the right track for sure. Last year I was leaving on 5-7 psi off the line. I tried alot of different air pressures and I did gain some ground. I was able to get myself consistant which was also a step in the right direction. Now I am looking to take it to the next level. I mean I have to power to accomplish my goals, but I need the suspension to work in order to do that. So are I see alot of suggestions about the -4 pinion angle. Maybe I need to get out and try that.

on a side note would it be a good Idea to weld in some gussets on the torque boxes. Pretty much a free mod, it will only cost me time. Another question that I have is the bars to triangulate the suspension. like the edelbrock 5210's. are they worth it or just a waste of money??

eBay Motors: Edelbrock 5210 MONTE CARLO Tubular Brace (item 180325098765 end time Mar-02-09 12:29:42 PST)

 

[WINDMILL]

Here check this out,, this was my car on 295x50 hard tires
http://www.turbobuick.com/forums/turbo-lounge/268199-something-different.html

 

[buttonfly]

I actually remember reading that when you guys first started that thread!

Thats it I am going to buy my air bags! I do appreciate everyones feedback on this!

 

[buttonfly]

Windmill I may have a few more questions for you, but I ordered a set of bags from Mike and Full throttle this morning!

I again appreciate everyone's info here. Thank you to all!