IRS drag racing setup?

[N/A Q45]

Trying to get my Q45 to hook up. My biggest question is to squat or not to squat?

I'm running 275 DRs at 18psi and still only get a 2.3-2.2 60ft from lack of traction, the thing just spins. I've tried what worked on my 240sx but the Q is just too heavy too get the front wheels to lift with out having 100% good traction, have tried stock suspension (it squats to the stops if it hooks) best 60ft was 2.2. Put in travel limiters so it only squats about 2" and then it lifts the front, still with a best of 2.2 60ft.
Neither of these combinations gave it 100% traction it it spins about the same but with the limited travel it doesn't waste any energy squatting on shifts which is better.

Anyone on here do some serious drag racing with IRS?

I don't want to have to run 300s out back but it almost looks like I will have too, and I can not launch any lower then the 2200rpm stall.

[themadscientist]

Preload. I set my old Skyline for positive camber at rest so under acceleration it would sink into a flat stance for maximum traction.

[N/A Q45]

Preload. I set my old Skyline for positive camber at rest so under acceleration it would sink into a flat stance for maximum traction.

I even tried that too. It's just getting it to start to hook the first 1.5ft, with my camber set like you're saying it made it even worse.. I'm almost thinking I need to raise the front end more to improve the angle of the rear end to make it want to under drive the car more.
What tires did you run and hp?

[themadscientist]

Nitto drag radials, under 300hp. With street tires it would spin, but my buddy who also had pretty much the same car could get great hookup. He had a much smoother launch technique than me, though. You are going to have to spend some time finding the right balance in your launch so you can bring the power up as quick as possible without breaking loose. The Q is not going to cooperate very much. If you lift the front it may help your launch, but you will then have an air plow causing drag and lifting weight off your steering wheels. Kind of retro.

[N/A Q45]

Nitto drag radials, under 300hp. With street tires it would spin, but my buddy who also had pretty much the same car could get great hookup. He had a much smoother launch technique than me, though. You are going to have to spend some time finding the right balance in your launch so you can bring the power up as quick as possible without breaking loose. The Q is not going to cooperate very much. If you lift the front it may help your launch, but you will then have an air plow causing drag and lifting weight off your steering wheels. Kind of retro.

Probably the same kind of tires I'm running then, once I get the tires to stop spinning and then the vvt/vve kick off the front end comes right up and stays there until I'm in between the 1/8th and 1/4mile then it slowly drops down a little, I will just air foil the belly of the car if that turns out to get it to hook. My 60ft times are just terrible. . If I was high 13s with a 2.3 60ft I should be in low 13s with a 1.9ish I would hope.
I've tried to roll off the line and then get on it but it still just spins.. I think I'm going to have to pull off some magic lol.

[flohtingPoint]

Getting proper tires is the first step. I do 2.0's with my FRC on Hoosier A6's ( http://scca.cdn.racersites.com/prod/a** ... 060_RT.pdf ), but these are not drag tires.

[N/A Q45]

Getting proper tires is the first step. I do 2.0's with my FRC on Hoosier A6's ( http://scca.cdn.racersites.com/prod/a** ... 060_RT.pdf ), but these are not drag tires.

I run Nitto NT-555r DRs 275/50r15s.. my buddy that has the exact same tire and can cut 1.8s with in his 69 mach1 but that's a lighter car.

[themadscientist]

"69 mach 1"
"lighter (than mine) car"

That's depressing.

[N/A Q45]

Lol it is what it is. .

[flohtingPoint]

Getting proper tires is the first step. I do 2.0's with my FRC on Hoosier A6's ( http://scca.cdn.racersites.com/prod/a** ... 060_RT.pdf ), but these are not drag tires.

I run Nitto NT-555r DRs 275/50r15s.. my buddy that has the exact same tire can cut 1.8s with in his 69 mach1 but that's a lighter car.

What's good for the goose isn't always good for the gander. Your buddy has a totally different car, this tire/tire size may not be good for your car. If you look at that list on my link, almost all the cars that dont have a class designation of "Street Touring [Whatever]" are on Hoosier A6's. Some run better 60' than me, some run worse. You cant compare two cars that are not identical. You also have to take into the consideration of how many runs are put on the tires, how many heat cycles, how old is the date-stamp on them, are you bagging them after each event to keep them fresh, etc.

Again, I would say, I would look into getting better tires.

[themadscientist]

What he said.
Your buddy has a live axle = no camber change as suspension squats.

[N/A Q45]

Yeah I agree with you, that's what I have been thinking, I know you can't really 100% compare the tires on two different cars but if they were s*** tires he wouldn't be able to get those 60ft times is all I was implying. My car is heavier so it needs more traction than a lighter car.

You suggesting a better tire or wider or both? I know I could probably hook with 26/10.0/15 MT or Hoosier slicks but I want to run the same on the street as at the track and slicks are not good or legal on the street lol. But I might just have to run slicks and then I'll know I'm going to hook, then change them after the track..

[themadscientist]

The tires are not at issue here. He gets 100% contact patch all the time, yours is probably 90% at best, growing and shrinking as your suspension moves up and down. I think you have good tires, you just need to get that suspension under control so they can work. I'm a newb when it comes to suspension setting; it's a complex art, but I would get some stiffer springs with harder shocks and adjustable upper links to dial in the camber. I think it's the excessive movement and changing camber and contact patch that's screwing you. get the range of motion reduced and make movement more controlled so it can absorb strong shocks rather than break loose, but otherwise maintain a controlled motion.

[N/A Q45]

The tires are not at issue here. He gets 100% contact patch all the time, yours is probably 90% at best, growing and shrinking as your suspension moves up and down. I think you have good tires, you just need to get that suspension under control so they can work. I'm a newb when it comes to suspension setting; it's a complex art, but I would get some stiffer springs with harder shocks and adjustable upper links to dial in the camber. I think it's the excessive movement and changing camber and contact patch that's screwing you. get the range of motion reduced and make movement more controlled so it can absorb strong shocks rather than break loose, but otherwise maintain a controlled motion.

Check, and check! Lol. I have adjustable camber control arms with ball bearings, and have suspension stops that limit the travel to around 1.5 inches in the rear, I noticed a huge difference from just the suspension stops alone but it's not enough. . The car tries to hook, I mash it at the line, the front end comes up, hits my rear stops before the car moves and then it spins like a motherfcker until I get going and it hooks again but for good.
My rear bushings are pretty shot so I'm just waiting for them to come in, hope that makes a big difference.

[WDRacing]

Just wondering why you went with 275/50's and not 275/60's? I always used BFG or MT ET streets. The 60 series might give you that extra "squat" you're looking for.

[N/A Q45]

Just wondering why you went with 275/50's and not 275/60's? I always used BFG or MT ET streets. The 60 series might give you that extra "squat" you're looking for.

I actually had 275/60r15s but they affected the gearing ratio to much off the line which is already pretty bad in these cars to start with.

I was only able to get a 2.2 with those as well but that was before I had the working properly. . It's making a lot more lowed now then it did when I tried the 60s. + they raised the rear a inch higher so the cars chassis had to do more work to get the front end to come up. The only thing I gained was I could run 2nd through the lasers at the end instead of having to shift to 3rd. My mph went up but et droped.

The tires in my picture are actually the 60s lol I haven't taken one with the 50s and put it up yet.

I'm thinking a lot of it has to do with our garbage track we have to use. I get more traction on the street on fresh pavement than our strip-

[N/A Q45]

I'm able to run a 0-60mph in 4.8sec now with the 50s with a shift, when I had the 60s I was getting 5.2sec without a shift.

The 60s would be my first choice if I changed my gearing though so I can utilize even more sidewall flex.

[flohtingPoint]

The tires are not at issue here. He gets 100% contact patch all the time, yours is probably 90% at best, growing and shrinking as your suspension moves up and down. I think you have good tires, you just need to get that suspension under control so they can work. I'm a newb when it comes to suspension setting; it's a complex art, but I would get some stiffer springs with harder shocks and adjustable upper links to dial in the camber. I think it's the excessive movement and changing camber and contact patch that's screwing you. get the range of motion reduced and make movement more controlled so it can absorb strong shocks rather than break loose, but otherwise maintain a controlled motion.

Without knowing anything about the tire history (ie how old they are, how much they've been abused, how many heat cycles have been through them), I find it impossible to rule them out. Tires are the most important part of any competition vehicle (obviously you need the thing to be running and such), all the HP and suspension mods cannot cover up bad tires. We have classes in the SCCA where you're allowed to do exhaust/suspension/ecu mods/intake/lightening but you're limited to 140+ treadwear tires, and the pointy end of these classes, Street Touring R (consisting of S2000's and NC Miata's), is slower than it's respective Stock equivalent class (B-Stock/C-Stock which consists of the S2000's and NC Miata's) because Stock gets to run on R-Compounds.

Below is an image of RT's and 60' times from the New Jersey Pro Solo (drag launch followed by autocross course). All the runs were done on the same type of tires (Hoosier A6, 295/17 front, 315/18), but I had two sets of tires; one set was from 2010, the other set was from 2012. The sheet got a bit messed up by the formatting, but all the same, the info is right there.

The runs in yellow are on the tires from 2010; 2.4 cold, 2.2 best warm for 60'. The tires in red are from 2012; 2.4/2.2 cold 1.9 best for 60'. Heat cycles, age, wear greatly affect tire performance. I was running the 2010 tires to get a dial in on the Vette for the surface we were at, then bolted on the 2012 tires when it was time to party.
Note* Yes my RT's are a**, I hosed the tree every run =P Same clutch drop, just bad light timing. We normally have LED trees, this was an actual bulb, meaning you kinda had to pre-drop after the 2nd light as the light comes on at a different rate. I jacked that up nearly every run =P



I would recommend getting some proper tires and a set of rear wheels so you can change them at the track. The tires will fit fine in your back seat, you can take them to the track with no issues. When you're not running on them, wrap them in pallet wrap and store them somewhere they wont get super cold or heat cycled by the elements.

Note* One set is unwrapped, I was in the process of wrapping them at the time of the photo. Took the picture for reminding folks to write letters pertaining a proposal in the SCCA to remove r-compounds from stock.

[N/A Q45]

The tires are not at issue here. He gets 100% contact patch all the time, yours is probably 90% at best, growing and shrinking as your suspension moves up and down. I think you have good tires, you just need to get that suspension under control so they can work. I'm a newb when it comes to suspension setting; it's a complex art, but I would get some stiffer springs with harder shocks and adjustable upper links to dial in the camber. I think it's the excessive movement and changing camber and contact patch that's screwing you. get the range of motion reduced and make movement more controlled so it can absorb strong shocks rather than break loose, but otherwise maintain a controlled motion.

Without knowing anything about the tire history (ie how old they are, how much they've been abused, how many heat cycles have been through them), I find it impossible to rule them out. Tires are the most important part of any competition vehicle (obviously you need the thing to be running and such), all the HP and suspension mods cannot cover up bad tires. We have classes in the SCCA where you're allowed to do exhaust/suspension/ecu mods/intake/lightening but you're limited to 140+ treadwear tires, and the pointy end of these classes, Street Touring R (consisting of S2000's and NC Miata's), is slower than it's respective Stock equivalent class (B-Stock/C-Stock which consists of the S2000's and NC Miata's) because Stock gets to run on R-Compounds.

Below is an image of RT's and 60' times from the New Jersey Pro Solo (drag launch followed by autocross course). All the runs were done on the same type of tires (Hoosier A6, 295/17 front, 315/18), but I had two sets of tires; one set was from 2010, the other set was from 2012. The sheet got a bit messed up by the formatting, but all the same, the info is right there.

The runs in yellow are on the tires from 2010; 2.4 cold, 2.2 best warm for 60'. The tires in red are from 2012; 2.4/2.2 cold 1.9 best for 60'. Heat cycles, age, wear greatly affect tire performance. I was running the 2010 tires to get a dial in on the Vette for the surface we were at, then bolted on the 2012 tires when it was time to party.
Note* Yes my RT's are a**, I hosed the tree every run =P Same clutch drop, just bad light timing. We normally have LED trees, this was an actual bulb, meaning you kinda had to pre-drop after the 2nd light as the light comes on at a different rate. I jacked that up nearly every run =P



I would recommend getting some proper tires and a set of rear wheels so you can change them at the track. The tires will fit fine in your back seat, you can take them to the track with no issues. When you're not running on them, wrap them in pallet wrap and store them somewhere they wont get super cold or heat cycled by the elements.

Note* One set is unwrapped, I was in the process of wrapping them at the time of the photo. Took the picture for reminding folks to write letters pertaining a proposal in the SCCA to remove r-compounds from stock.

Lol I think you need more tires!

My tires are brand new, I have had these 275/50s on for about a month and three race events. I probably just need some slicks and call it a day. Kind of like you're saying.

[flohtingPoint]

I do a LOT of racing =) I just got back from Lincoln, Nebraska where I was at Spring Nationals, getting my dial in on the Vette for the National Championship. My Vette logged somewhere around 50 or so runs there in competition and test and tune.

I would get whatever the best tire you're allowed, no sense leaving time on the table. Grab the best tire in your budget, get a set of rear wheels for it (you can get spun steelies for very cheap in whatever backspacing you want, look up race steelies and you'll find TONS of companies that will make them for very cheap), and then tune from there. If there are no rules against tire compound (or bias/radial allotments), bolt up the good stuff and go racing!

[themadscientist]

Sort of the reverse from the drifters where they grab crappy tires and throw them on the roof to bake.

[N/A Q45]

Sort of the reverse from the drifters where they grab crappy tires and throw them on the roof to bake.

Lol I think some of the civics around here do that because they just keep spinning and think they are quick while running 16sec

[N/A Q45]

I do a LOT of racing =) I just got back from Lincoln, Nebraska where I was at Spring Nationals, getting my dial in on the Vette for the National Championship. My Vette logged somewhere around 50 or so runs there in competition and test and tune.

I would get whatever the best tire you're allowed, no sense leaving time on the table. Grab the best tire in your budget, get a set of rear wheels for it (you can get spun steelies for very cheap in whatever backspacing you want, look up race steelies and you'll find TONS of companies that will make them for very cheap), and then tune from there. If there are no rules against tire compound (or bias/radial allotments), bolt up the good stuff and go racing!

Well we don't buy cars not to use em! Sounds like you use yours pretty good


-how is your suspension set up, do you have much squatting?

[flohtingPoint]

My FRC is set up for national level SCCA Autocross in the A-Stock class, so my suspension modifications are fairly limited. I'm allowed to change dampers, which I've done and replaced them with Koni Sports (two rotations from full soft in the rear). My rear alignment is:
.3 deg neg camber
1/8th toe in

The Pro Solo format uses a drag tree launch and then has an autocross course following it, thats where I get all my data from launches. I do miss my shifter kart though, 1.6 60's were nice.

[WDRacing]

You should give some TrackBite a try. It's only $50 and I have read pretty good stuff about it.

http://www.summitracing.com/parts/pji-sp-162

[N/A Q45]

I would expect your car to run much quicker 60ft time if if was set up for only drags though FlohtingPoint.?

And WDRacing lol if I were able to use that stuff on the track there would probably be a fight behind me for my lane

I think I might just have to pull some lowend power and put it up top until I get some slicks. Going to give this setup one more try here on the 14th hopefully my new bushings come in and I get them in before.

[flohtingPoint]

I would expect your car to run much quicker 60ft time if if was set up for only drags though FlohtingPoint.?

And WDRacing lol if I were able to use that stuff on the track there would probably be a fight behind me for my lane

I think I might just have to pull some lowend power and put it up top until I get some slicks. Going to give this setup one more try here on the 14th hopefully my new bushings come in and I get them in before.

I could probably find a tenth or so if I softened the rear a bit more, if I swapped tires or bias-ply, I could probably find another tenth, as A6's aren't really for drag racing.

You can see in the picture, there is a good amount of rear travel already (with how the car is leaning), it squats pretty well on a launch. The FE3 suspension has weaker rear springs than FE4, so hooking up isn't much of a problem.



Those tire treatments like that or trackclaw or formula V are all well and good, but if you're using them on tires you DD on also, BAD idea. I used Form V on some older R-Comps back in 2010, it worked out ok, but kinda not worth the effort it takes to do it. You have to coat them, wrap it overnight and let it sit for at least 24 hrs or the tires get greasy.

[WDRacing]

I'd never use a traction compound on non drag radials or slicks.

They are easy enough to use though. Just have the mix in a spray bottle, do a burnout, roll fwd, treat the immediate area in front of the rear tires, roll onto the treated area, do a 1-2 rotation power brake and proceed to the line. You're only treating a small patch of pavement prior to the starting line and the majority of the compound ends up on your tires. So there is really no benefit to those following you.

If you want a quicker 60', this is the answer. Do some reading, pretty much everyone has nothing but good to say about it.

[N/A Q45]

You find more traction in the rear with softer suspension? Humm my 240 liked stiffer, but I probably should definitely try atleast the stock suspension again I guess on the Q with no suspension stops. Funny thing about my Q is I actually have the quickest 60ft on stock suspension with much smaller and less tacky summer tires (235/45r17s) 2.23 vs 2.25 on my Nittos with the suspension stops. .

But I noticed on the street (running the exact same tires both times) that with stock suspension if I floor it in 1st at 50kph it would just spin but with the stops it would hook and go. I increased the lowend power a good bit from when I had tge 235s though so I probably just need more tire on the ground to hold it. Funny though.

[flohtingPoint]

The more rear weight transfer you get, the more pressure there is on the tires, the more force there is pushing them to the ground, the more they will hook up. It works not just for drag, but for trying to find traction on any RWD car. We utilize a very thick/solid front swaybar to get even more cross-weight transfer when cornering to load the outside rear tire. When the car isn't turning enough, we need to dial in more slip, so we will increase tire pressures and bump the damping up.