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-   -   Analyze this timeslip (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/analyze-timeslip-155817/)

HeatTreated 02-06-03 12:14 PM

Analyze this timeslip
 
Attached is my latest Timeslip
But first know my Dyno results were 233 HP & 222 TQ with an A/F ratio of 11.5.
I only have Intake and Exhaust.
yes, I have a manual.
The best I could manage was a 14.0 @100mph. I only got about 8 runs in and after adjusting tire pressure, spraying IC and figuring out a launch, I settled at 26 psi in the rear tires and launched at 3400rpms. I run susquential still at stock boost levels. How much room for improvement is there?
-feedback please.

HeatTreated 02-06-03 12:17 PM

Pics..

HeatTreated 02-06-03 12:20 PM

pic

turboGXL 02-06-03 12:31 PM

The track sucked that day.. my best was a 14.5

I dunno bout you, but I get pretty good launches from 5000 rpms.

martini 02-06-03 12:48 PM

That's a good MPH. I bet you could bring the ET down a couple tenths if you launched it better.

rynberg 02-06-03 01:29 PM

Re: Analyze this timeslip
 

Originally posted by HeatTreated
Attached is my latest Timeslip
But first know my Dyno results were 233 HP & 222 TQ with an A/F ratio of 11.5.
I only have Intake and Exhaust.
yes, I have a manual.
The best I could manage was a 14.0 @100mph. I only got about 8 runs in and after adjusting tire pressure, spraying IC and figuring out a launch, I settled at 26 psi in the rear tires and launched at 3400rpms. I run susquential still at stock boost levels. How much room for improvement is there?
-feedback please.

hmm......

The one and only time I've been to the strip, my best was a miserable 14.1 @100 mph. This was with a downpipe and RB exhaust and it was over 80 degrees.

I dynoed at 240 rwhp/225 rwtq. I also lowered my tire pressure to about 25-26 psi. Your 60' time is identical to my last few runs.

I guess we just suck at drag racing. :)

ttpowerd 02-06-03 01:36 PM

Not terrible. There is a some room for improvement if the car stays as is. If you upgrade the car more then the potential is limitless (to a point) :D

Snook 02-06-03 02:34 PM

I don't think there is much room for improvement with your car and mods right now. You had a pretty good launch that time. I've only been to the track 1 time and I had a hard time with my launch although I had it perfected on the street. I just got a little nervous and wasn't used to having to be ready so quickly after staging. My best was a 2.2 60 time and I could tell that the launch wasn't perfect but it felt pretty damn good so I was shocked that it was not a near 2 flat 60 foot time. I had intake, dp, catback, pettit ecu, very mild streetport and ran totally stock boost and got a 13.5 flat on that run which was my best with that setup.

So I think you did all you can do with your mods and you are a pretty good driver. If you don't have a downpipe then that will be a huge upgrade for you. After that and the same 60 time I see you getting a 13.7

good job man

Tom93R1 02-06-03 03:08 PM

That is almost identical to what I ran with down pipe and high flow cat.
Now I have added a Racing Beat cat-back and a Power FC running the base map and with a passenger I ran 13.94@102.5 and 13.99@103. Following that I got kicked out for being in the 13s and having a passenger.
I know I suck at drag racing, and since these runs came about a year after the last time I had drag raced I am probably not getting any better. Maybe could be a bit better had I remembered to drop the air pressure in the rear tires.

HeatTreated 02-06-03 04:30 PM

Well thanks for the input.. The thing that made me question everything is my friend has an S2000.. with just Cold Air Intake ran a 13.8 @100mph.. Dynod right after my car and put down only 207 HP 143TQ. So explain that one! sure he wraps it out to 9k rpms. but if the weight and most everything else is similiar (body spec wise) and I have a huge advantage on power and torque... why is he doing so well? (without drivers - S2ks = 2900lbs / my 7 = 2800)
*TurboGXL.. which car was yours? I dont think I ran into you? is it red like in the pic? next time we'll have to meet up.
I got all my runs in early.

turbojeff 02-06-03 06:09 PM

It's all in the launch. I ran a 13.954@99.45 mph on my very first pass ever with my FD with a passenger, outside temps were in the 75-85F range (don't really remember).

The next two runs without the passenger were 14.2 and 14.1.

A year later I took my now DP, Efini y-pipe and cat-back wearing FD to the same strip. First pass was a 13.97@100mph:(. A few runs later I slipped the clutch just slightly more out of the hole and turned a 13.58@102.85mph.

What I'm trying to point out is not what the fastest time someone ever turned with XXX mods, but what a difference just slight changes in launching made.

Jeff

mjw 02-06-03 07:34 PM


Originally posted by HeatTreated
Well thanks for the input.. The thing that made me question everything is my friend has an S2000.. with just Cold Air Intake ran a 13.8 @100mph.. Dynod right after my car and put down only 207 HP 143TQ. So explain that one! sure he wraps it out to 9k rpms. but if the weight and most everything else is similiar (body spec wise) and I have a huge advantage on power and torque... why is he doing so well? (without drivers - S2ks = 2900lbs / my 7 = 2800)
*TurboGXL.. which car was yours? I dont think I ran into you? is it red like in the pic? next time we'll have to meet up.
I got all my runs in early.

What was the weather like that day at the track? Remember.. you are turbocharged/intercooled so air temps will affect the output of your car much more than an S2000. Especially after a few runs and the car just sitting after each run, the intercooler can heatsoak quickly.

HeatTreated 02-07-03 01:20 PM

Turbojeff, Im curious to know what you launched at and how much more 'feathering' you did?
Oh I kept my IC and other piping plenty cool with Ice and a spray bottle.

matty 02-07-03 01:28 PM

u guys must be at high elevation or have high miles. A FD with some light mods like that should run low 13s pretty easily. I ran 12.7 @ 111 mph with intake full exhaust and power fc on street tires..i know people with the same setup that run low 12s on ET streets.
When are you guys shifting (rpm)? how r u launching?

Tom93R1 02-07-03 02:00 PM


Originally posted by matty
u guys must be at high elevation or have high miles. A FD with some light mods like that should run low 13s pretty easily. I ran 12.7 @ 111 mph with intake full exhaust and power fc on street tires..i know people with the same setup that run low 12s on ET streets.
When are you guys shifting (rpm)? how r u launching?

My launch is why I am slow. I let the clutch out too quickly because I dont want to burn it up, it has 74k miles on it now and I want it to last about 10k more.

How exactly do you launch to get a 12.7 on street tires with so few mods?

matty 02-07-03 02:43 PM

i dropped the clutch at 2700-3000rpms..tire pressure at 25 lbs..i cut a 2.003 60' time. this was my second attempt at drag racing so i am sure i could have done better. at first i tried 3500 rpms and got huge wheel hop..bad..very violent on the car.

i think another imprtant factor is that my car had under 25k miles last summer when i took it to the strip...it would be logical to think that a car with 70k miles wouldnt run as well.

Dragueur 02-07-03 02:52 PM

hey......
 
my first tiime at the track...

all stock with boost leak coming from my bov. wasnt getting 10-8-10 or even close to it.

my 60 ft was 2.3.

1/4 was 14.0 at 101 mph. pretty hot day..almost 80.

looks like i had a better top end than you..just that i had boost leak and my 60 ft sucked due to wheel hop. :(

it should be better now...hopefully 13s. :cool:

HeatTreated 02-07-03 04:04 PM

Heres another question..
I tend to shift at 7k rpms. Do to the fact that my dyno showed power loss dropping fast by then. So need to wrap it out to 8k+ right?
and you guys who are running mid 13s with only a few mods, what your launching techniques?

Tom93R1 02-07-03 04:58 PM


Originally posted by matty
i dropped the clutch at 2700-3000rpms..tire pressure at 25 lbs..i cut a 2.003 60' time. this was my second attempt at drag racing so i am sure i could have done better. at first i tried 3500 rpms and got huge wheel hop..bad..very violent on the car.

i think another imprtant factor is that my car had under 25k miles last summer when i took it to the strip...it would be logical to think that a car with 70k miles wouldnt run as well.

I usually launch at about 4K rpm and get a little wheel spin, the one time I tried launching at 3k or below I bogged really bad. I have about 30k on my motor so it isnt tired yet, I think it is all in the driver skill or lack of driver skill in my case.

greg schroeder 02-07-03 05:55 PM

my observation
 
I've made few bone stock touring passes with a couple different 3rd gens.

My first try was a 13.9 @ 105mph, 1700ft, 80F, stock tires, wheel hop, 3000 rpm launch.

High 13s / Low 14s seem to be fairly typical from what I've observed if you get a half way decent launch and you hit the shifts. With a bad launch and a missed shift add a good second to the time.

mr_ouija 02-07-03 08:54 PM

My best 60' was 2.19 and that wasn't really a drag launch at all. I ended up running a 14.11, had to let off because the water temp was rising (on stock gauge). Didn't help though, she still overheated and popped the rad. :(

RX7SpiritR 02-07-03 11:20 PM

Wanna know the best way to launch? Rev it up to about 5k RPM's and then let the clutch out but your only half peddling it when you let it out, once you start going floor it! Now if you do this right you wont burn out at all and you wont get wheel hop and you'll be well on your way to having extremely fast runs along with launch improvements of your own. ;)

EDIT:I was just looking over everything else and noticed EVERYONE is only launching at about 3k RPM's........ why? You should be launching at around 5k RPM's like I said. You have to get the turbo's spoolin really good so when you take off you really take off, that's what the LSD was made for. It takes a lot of practice to get it just right at those RPM's, but it's very worth it when you look at your times afterwards. You may not get it just right every single time, but you'll have other runs you can do. At least try it out some before you start yelling at me for some reason, not sure why you would but thses are just my suggestions to you as I'm trying to help you on your launch, you don't have to take my advice. Have fun practicing and good luck on improving your times.:p:

turboGXL 02-08-03 12:02 AM

Well, mine is 90 turbo, and I burnt my clutch up that day.

RX7SpiritR 02-08-03 12:12 AM

o......

turbojeff 02-08-03 12:58 AM


Originally posted by RX7SpiritR
Wanna know the best way to launch? Rev it up to about 5k RPM's and then let the clutch out but your only half peddling it when you let it out, once you start going floor it! Now if you do this right you wont burn out at all and you wont get wheel hop and you'll be well on your way to having extremely fast runs along with launch improvements of your own. ;)

EDIT:I was just looking over everything else and noticed EVERYONE is only launching at about 3k RPM's........ why? You should be launching at around 5k RPM's like I said. You have to get the turbo's spoolin really good so when you take off you really take off, that's what the LSD was made for. It takes a lot of practice to get it just right at those RPM's, but it's very worth it when you look at your times afterwards. You may not get it just right every single time, but you'll have other runs you can do. At least try it out some before you start yelling at me for some reason, not sure why you would but thses are just my suggestions to you as I'm trying to help you on your launch, you don't have to take my advice. Have fun practicing and good luck on improving your times.:p:

OMG, I can't believe I'm going to agree, sort of, with you.

My launching techinique is hard on the clutch, you need to have the second turbo on-line when the clutch hooks up. That means I agree with the above method. Slip clutch slightly(like mostly hooked up, clutch foot releiving a little grip) while feeding in lots of throttle, keep it as close as you can to 4500rpm. You've got to do this fast of course, if you don't you'll really melt the clutch.

This opinion is based on an ACT street/strip clutch. If you have a stock clutch it'll do a lot of the work for you, by slipping on its own. If you have a metal clutch slipping it is hard and will destroy the flywheel and PP.

I also run about 22psi in my tires.

Jeff


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