Bearzah

iTrader: (6)

Hey guys... After a few conservative trial races, i'm ready to get serious.
I'm looking for suggestions on launch RPM settings for a Bee R limiter (yet to be installed).
I'll also be ditching my street-meat for a set of drag radials.
My previous outing I was feathering the throttle to hold about 4k-4.5k rpms. Pretty serious bog in power or wheel spin off line. More rpms at launch spins the tires, less rpms bog it down under 2k rpms.
My 60 ft times where in the 2.5 - 3 second range... NEED MORE TRACTION!!!
I'm not expecting miracles.... I'm just looking to improve my 60 ft times as the car runs like a raped ape once its rolling... Generally, you'll see a 2-fold decrease in your ETs for every improvement to your 60 time.
Lowering my 60 ft times to 2 sec would net a 1 - 2 sec decrease in my ETs... What's a realistic 60 time for a street-weight wide body FB (2,800 lb w/ me in it & full fluids)?

Will be running 26x10x15 drag radials

Here's a list of the car:

'85 Mazda FB3S RX7...
Turbocharged 13B rotary engine...
S5 large street port..
Turbotechnics T4OE hybrid turbo:
60-1 compressor wheel, ported S5
hotside w/ P-trim turbine wheel,
Running 14-15 psi all day...
750cc prim/1000cc sec
RC/Injector Dynamics...
Modded S4 fuel rails, Fuelab boost-
referenced FPR... RTEK 1.8...
Apexi Neo... Raptor shift light...
Bee R 2-step launch control (soon)...
S5 T2 tranny... ACT stage-3 clutch...

As long as I don't break the driveshaft u-joints (not likely as only a year old) OR have my differential explode (It's a low-mile '83 GSL large axle... About the best I can run in this bolt pattern. Im running Kosei K1's that im not willing to give up in 4x110 w/3.90 gears)... It may be fun :-)

Looking for a POSITIVE experience here people... Don't hate... Looking for advice from knowledgable people WITH experience to back up their suggestions.

Thanks ... BRAP!!

1BADSP

iTrader: (4)

What do you have for a flywheel,heavier is better for drag racing as it keeps the stored inertia up when you let out the clutch,also i would use drag radials not full slicks as you will snap factory axles like twigs,you will have to play with 2 step pills to get the launch rpm correct for the best 60' time.you can make some adjustable mounts for the 4 link to be able to change the instant center witch will also help get the car moving off the line better.after that a lot of seat time to get use to the car and how it reacts.

1BADSP

iTrader: (4)

doh!!, i read that a second time and see you will be using drag radials.

Bearzah

iTrader: (6)

Stock s5 turbo flywheel

Bearzah

iTrader: (6)

I'm aware it'll take some fine tuning... I just was hoping for real life experience to chime in.. Maybe someone with similar setup?

1BADSP

iTrader: (4)

^i am talking from real life experience,you can ask around if you like,i'm not sending you on a wild goose chase.but that's ok i will stop now.

Bearzah

iTrader: (6)

Paul, I was hoping for general numbers... Like I asked for.

What kind of 60' times should I aim for with drag radials?

What's a good 2-step launch rpm?

Neither of these have you answered. Although I appreciate the input, I'm looking for answers or experience using a 2-step... I'm kinda surprised how difficult this is to get a straight answer (this isn't my only resource I've been taping).

Guess I'll start at 5k... Try a little less and a little more to observe 60 times.

1BADSP

iTrader: (4)

i did answer,you will have to play with launch RPM.you want the highest rpm without spinning the tires.if you have dynoed your car a good launch rpm is about a 1000 rpm over peek torgue.yes,there are vague answers,but no combination is the same so you get a starting point and work from there.a good 60' is 1.70.i have ran the best of 1.63 on old slicks.that is also a trade off.the better the 60' the more chance of breaking something from the tire hooking.just remembered if you don't already have it you will need a driveline loop when using slicks.hope that helps.

rotorholic

iTrader: (53)

I have a real life advise for you 26x10x15 drag radials will break a axle if you're lucky or strip the bolts on the rear caps on any first gen rear end "FIRST" time it really hooks

Looking for a POSITIVE experience here people... Don't hate... Looking for advice from knowledgable people WITH experience to back up their suggestions. This statement was really unnecessary

Bearzah

iTrader: (6)

Ok, well, what would you suggest than?

Bearzah

iTrader: (6)

Is one needed for DOT slicks? Just curious, not a big deal to fab one up

1BADSP

iTrader: (4)

1/4 in thick steel mine is only about an inch wide.you bend the first section to fit the trans tunnel.the section will run across the bottom of the floor pan so you can bolt it to the floor,you may need to put a bend in it to clear the driveline when you jack up the car .then weld the 2 section together.so when it is done you will have a on piece bolt in loop. it needs to go i think it's 8- 12 inches back from the front u joint.if any of that is confusing,you can google driveline loop for a better visual.

Bearzah

iTrader: (6)

Was just curious... I'm aware WHAT a loop is :-p
I have one in my '66 Chevelle

1BADSP

iTrader: (4)

i don't know if one is needed for dot drag radials,but i would put one in and be safe,because if you ever explode a driveline you will be glad you have one.i had a driveline break on my RX-3 and no loop,to this day the holes from the debris are still in the floor.very scary ****

Bearzah

iTrader: (6)

^ well damn

1BADSP

iTrader: (4)

sorry didn't mean to offend,just trying to explain.cool you have a 66 chevelle.

Bearzah

iTrader: (6)

The "stable"

Samito Built

iTrader: (38)

When I had my Gsl-se it was stock with all bolts on still fuel injection. It had 4 puck clutch, Nitto drag radials on stock 14inch wheels and traction bars reinforced. I still pulled a 1.90 60 ft this car had no power so I would smoke the Hondas and they would play catch up and the end of the 1/8 it was pretty funny. I couldn't imagine if it was 4 port bridge with a carb or something in that nature.

Oh ps launched about 7k

Samito Built

iTrader: (38)

I would recommend some kind of flow control tilton, clutchmatsers, or magnus. This will prevent you from snapping a axle. Instead you will be slipping the clutch and taking the stress of the drivetrain. With the drag radials it will increase traction. I would also recommend reinforcing those traction bars. As soon as the hooks it going to bent them like nothing just my experience.

Bearzah

iTrader: (6)

General concensis I'm getting is I really don't need a 2-step and will probably break things if I use one... Lol

I'm now considering another effort at the track with better tires and a higher launch rpm (feathering throttle) around 6k rpm...

Still listening to your guy's input though

Samito Built

iTrader: (38)

2 Step is aggressive I mean in my Starlet I was launching at 7k making 10pounds of boost on 2 step and was pulling a 1.37 60ft but I have a 9inch ford rear end with ladder bars and Mosier axles. So hell yeah 2 step all the way. But your using a factory rear end which now is the weakest part of the car. You wont be feathering if you use drag radials!

1BADSP

iTrader: (4)

a 2 step will keep it at a consistent rpm,it's just finding the right launch rpm for the best 60'.and preloading on the line will be easier on the drive train.

RXTASY57

iTrader: (2)

Get some slicks. They will take some of the shock out of it.
Get a driveline loop and possibly some Driveshaft Shop axles. I have broken the CV joints on those as well, but don't have the money to convert to a 8.8 rear yet.
My best is a 1.6 60" on BFG Drag Radials without a 2 step.
Get your launching down first, then worry about a 2 step.

Samito Built

iTrader: (38)

What size tire are you using on your drag car? What type of diff S4 T2 or kaaz just wondering. I just bought some 225 50 16 Hoosiers dot drag radials for my FD was wondering how strong is the t2 s4 diff....400hp+

RXTASY57

iTrader: (2)

I am using 8' wide Drag Radials. I run about 12 PSI in them and heat them up really good. Have a S4 diff as well and have had all the inards cryo treated. Haven't had any problems YET.
I am running close to 700 RWHP now and my biggest problem is the clutch. I just bout a new ACT XX Extreme that is supposed to hold 670 ft lbs. We will see. I was running a CM twin disk and it worked for about a year. I hate changing the clutch out! Talk about a PIA! I think I would rather just pull the engine and go about it that way!
I do see a 8.8 in my car in the near future.
Hey! do you run that yellow TII?