well it's physics right, so a cobra is going to squat, and one would want it to stay that way i.e. between shifts to maintain its fastest time down the track.. correct?
IRS Drag Suspension Set Up -- In here please..
- Thread starter S.V.T.
- Start date
Yes, I agree it's physics, and I think it's fair to say that the same physics apply the same way when trying to plant the tires on a RWD car with IRS or not. So, the next question is how to get the anti-squat in an IRS. I have no idea how to answer that, but suspect it would involve some serious cutting and fabricating by a better engineer and fabricator than me!
What the hell is wrong with some people??:shrug:
Every time an IRS question is asked someone has to say go solid??:bash:
I have poly subframe bushings, BF IRS brace and poly diff bushings.
Springs are the Eibach pro kit.
My best drag time is [email protected] w/1.67 60' time. This was done last week on 15" MT ET Streets with stock half shafts.
On Sunday I placed 1st in my class in an autodross event.
Yes, I like my IRS.
Soon I will be going with the complete bushing kit from Bruce.
well theres nothing wrong with me and if you follow my progress, i still have have an IRS myself. plus he was asking for a succesful drag suspension set-up. now if he would have mentioned auto-x and drag racing, thats a little different.
just look at who has less breakerage an IRS car or a car with a SRA? plus if all hes looking at doing is drag racing, thats a clear and cut answer for me. for the most part all the cars that are running high 8's and low 9's are SRA cars not IRS cars.
also, just b-cuz you havent broke anything and can run on your stock halfshafts doesnt mean that everyone else can.
just look at who has less breakerage an IRS car or a car with a SRA? plus if all hes looking at doing is drag racing, thats a clear and cut answer for me. for the most part all the cars that are running high 8's and low 9's are SRA cars not IRS cars.
also, just b-cuz you havent broke anything and can run on your stock halfshafts doesnt mean that everyone else can.
I apologize for being harsh.
It just seems that it is impossibkle to have an intelligent discussion about the IRS without some one saying "go solid".
That does not give the info that the OP requested.
I do have a spare set of half shafts incase mine break.
Happy Holidays:beer:
It just seems that it is impossibkle to have an intelligent discussion about the IRS without some one saying "go solid".
That does not give the info that the OP requested.
I do have a spare set of half shafts incase mine break.
Happy Holidays:beer:
I have my QA-1's set on 4 clicks for the slicks, 0 is the softest setting - 12 is the stiffest. I'm hitting low 1.4 60ft's leaving at 5,500, with a best of 1.38. Several of my racing buddies have done the same with the IRS. When the track opens back up next year I'll experiment with stiffening them up more - it'd be great if this brings my 60's down even more...:beer:
The biggest advantage that I know of with the solid is that 100 pound weight reduction. Viper's & Vettes are well into the 8's with their IRS's (solids aren't available for them). From 5 years of bracket racing I've come to the conclusion most break their half-shaft's due to wheelhopping on Drag Radials. I've seen several breakages with solids too. I feel an IRS, especially a beefed up one can compete with a solid when using Slicks or a soft sidewall tire. Do I think a solid is the best choice for the track - sure do, just like an IRS is the best choice for the street.
I think you're on the right track here. Cut maybe a full coil off and then you can play around with the bags and shock settings. And definitely slicks FTW!
To change the anti squat I think will have to include changing the mounting of some of the suspension components or the carrier. I'm struggling with what...
Everything that has been done for wheel-hop with the IRS changes the harmonic frequency of the over-all suspension package, the frequency of the spring being primary controlling factor and the others secondary. When we change/add frame connectors, tire sidewall, bushings, shock dampening (of the spring frequency) and air-bags change the frequency too.
I wonder about using a radically different spring frequency (not to be confused with the rate, although they are sort-of interrelated). A good no-hop spring frequency might give really crappy handling though.
Going to coil-overs would probably change the frequency alot, just due to the spring wire size and wind diameter.
Can anyone elaborate on how going to coil-overs affected their wheel-hop?
Last edited:
I went 1.61 60ft last time out, suspension is as follows:
stock springs cut 1 coil
stock struts, QA1 shocks
MMFLSFC
billetflow IRS brace
bruces differential bushings
The car transfered very little weight, so I'm currently swapping to 4-cylinder front springs and Lakewood 90/10's, maybe it'll tote a tire at 3,600lbs, we'll see
stock springs cut 1 coil
stock struts, QA1 shocks
MMFLSFC
billetflow IRS brace
bruces differential bushings
The car transfered very little weight, so I'm currently swapping to 4-cylinder front springs and Lakewood 90/10's, maybe it'll tote a tire at 3,600lbs, we'll see
so going on with my set up that i'd like: qa1's, laurel air bags, irs brace (red from billetflow), cut 1 coil on my stock springs, as far as flsbc's what do you think of laurel mountain's? my buddy had them, said they worked fine.. especially for the price under $90 bucks.. any ideas?
There is nothing wrong with having our suspension squat for what we are doing (test n' tune , brackets). On a professional level you wouldn't want it to squat because you are looking to get maximum performance. Where people go wrong is they don't address rebound, that's where you get unloading of the tires. Reducing the rate of rebound with a two-way adjustable shock will help the suspension unload slowly therefore reducing wheel spin.
^+1
wear can I get bruce's IRS kit???
See my sig!
At the moment I'm out of stock on upper control arm bushings but they are due in this week!
:thumbsup::coolman::beer:
YES!!! Thanks man!!!....order comming JAN 08...slo-poc....
so antex are you using the qa1 model mu7856P?
I'll have to check - but mine are the rear QA-1's not the fronts. I have the UPR K member/coil overs for the front with the tokia adjustable drag struts.
i think it's these, although they don't mention 12 way adjustable; however, i think these are it - DMU7856P
do you think front coilovers and struts are necessary? i was thinking of leaving my front suspension stock with just a cut coil.
my car is still going to be a daily driver for the most part.
do you think front coilovers and struts are necessary? i was thinking of leaving my front suspension stock with just a cut coil.
my car is still going to be a daily driver for the most part.
Off topic a bit. Are any of you guys running the ET's using a line lock?
As for the IRS. There was a guy in Vegas running ET's, line lock and a BF IRS brace. He would heat them bad boys up and drop it at 5,000 RPM. He was running consistent mid 11's. He said as long as the ET's hooked you would be fine with the IRS. And he was.
VPF
As for the IRS. There was a guy in Vegas running ET's, line lock and a BF IRS brace. He would heat them bad boys up and drop it at 5,000 RPM. He was running consistent mid 11's. He said as long as the ET's hooked you would be fine with the IRS. And he was.
VPF
Users who are viewing this thread
