Just challenged my best friend to a drag race at ATL dragstrip.

[RipperXX]

He has one of those spinning triangle cars...a 93 Rx something...duno what the prescription is for, maybe it needs a pill to get going?

Anyway its had a single turbo swap FMIC, 3" exhaust, duno what the fuel upgrades are but I remember theyre adequate, I want to say hes at 17psi of boost on pump gas, I forget what hes using for tuning. Supposedly the guy that rebuilt the engine, did the single turbo conversion and tuned ir for him xlaims 400hp, duno if thats flywheel or wheel..I do remember it pulls pretty hard.

Just pretty much FINALLY got my car where I want it...only took 14 years or so...thanks to Uncle Sam interfering..abd getting married...and having 3 kids. So its been a long tiring journey. But from what Im seeing of my 70-90mph times (2.3sec) and Links hp estimates at 22psi on 93octane (330) it looks like it ahould be a sub 12.5 second car. I wont know for sure if it is oe if I can launxh and drive it well enough until we heas to the strip, but a tank of gas ans dinner was wagered and accepted.

So beer, wings and a tank of gas is up for grabs. Either way it will ve a win regardless getting to drag race an old close friend. Only thing that stands in the way..is the wife doesn't know anything about it yet...

 

[RipperXX]

wow, dead in here, my thread on ar15.com got waaaaay more traction .

it has been suggested to me that his RX7 likely makes more than 400hp...oh well, hopefully he spins and nothing breaks on my end...i think if i get him on the launch like i ought too, he wont be able to real me in, in time.

 

[1990TSIAWDTALON]

Throw a splash of E85 in there for a little more kick!!! Or just come and borrow my car, we can put red popups back on her, . he wouldn't be able to tell the difference...oh yeah we need to put your rims on tho hehehehe.

 

[19gsx91]

Those mazda rotary engines are pretty horrible when it comes to torque, to my understanding they don't come alive until above 5kRPM.. So if he's willing to launch it hard.. maybe, otherwise I think you've got it.

 

[RipperXX]

Throw a splash of E85 in there for a little more kick!!! Or just come and borrow my car, we can put red popups back on her, . he wouldn't be able to tell the difference...oh yeah we need to put your rims on tho hehehehe.

I'm thinking a few galons of Xylene dumped in the tank and a bump in boost should do the trick, 22 is the limit on pump gas, 23psi and I get 2 degrees of ignition retard. Sooo shoot for 25-26 with a 1 to 1 ratio of Xylene to 93 pump. 4galons of each should yeild 8 galons of 105 octane gasoline.

 

[gofer]

It's just quiet in here because bench racing is a bust on Tuners anymore, it's allowed but looked down on by the general pop.

That being said, how "seasoned" is your old friend racing the RX-7 down a drag strip and how seasoned are you? Your ECMLink estimates and 70-90 times aren't what concern me racing a 400hp RX-7, its knocking the dust off and getting down the track for the first time in 14yrs for both you and the car.

The biggest kick in the balls for enthusiasts at the drag strip is them making their first pass expecting to run a specific time and they hit 2 seconds slower because of their inexperience. A better guess of how much power you're making and what your car is capable of running is looking at the trap speed, then it's just seat time and driver mod to get you to the cars capable ET's.

It sounds like a fun bet though, especially if neither of you go into it knowing what either car runs at the track. Be sure to post a video update if you remember to!


..,and for the record (based off of your mods listed in your cars profile) I'd guess you'd be <275awhp without cams on that setup so assuming a full weight 1g your trap speed is ~ 100mph and ET's ~ 13.5.

 

[19gsx91]

I agree with Gofer, especially as to why most people haven't commented, I was poking at the RX7 hoping someone with real experience in one would chime in, I know the RX8s aren't great, but I've only HEARD about rx7s.

The only thing I ask is that you post back and let us know the results, for better or worse!

 

[1990TSIAWDTALON]

And I too knew I shud get a slap on the wrist from Gofer, no problem. Lets just say be safe!
Sounds fun though...

 

[RipperXX]

It's just quiet in here because bench racing is a bust on Tuners anymore, it's allowed but looked down on by the general pop.

That being said, how "seasoned" is your old friend racing the RX-7 down a drag strip and how seasoned are you? Your ECMLink estimates and 70-90 times aren't what concern me racing a 400hp RX-7, its knocking the dust off and getting down the track for the first time in 14yrs for both you and the car.

The biggest kick in the balls for enthusiasts at the drag strip is them making their first pass expecting to run a specific time and they hit 2 seconds slower because of their inexperience. A better guess of how much power you're making and what your car is capable of running is looking at the trap speed, then it's just seat time and driver mod to get you to the cars capable ET's.

It sounds like a fun bet though, especially if neither of you go into it knowing what either car runs at the track. Be sure to post a video update if you remember to!


..,and for the record (based off of your mods listed in your cars profile) I'd guess you'd be <275awhp without cams on that setup so assuming a full weight 1g your trap speed is ~ 100mph and ET's ~ 13.5.

Its not full weight, A/c has been removed, spare tire, jack, tools, has a carbon fiber hood, no emissions equipment, FD3S wheels (14lb). XACT flywheel (11.9lb) aluminum 3.25" catback exhaust (15lb due to the stainless steel muffler) a few other small bits.

Seeing 40.9lb/min airflow at 22psi. It has been years but I have made a few passes at ATL Dragway. I dont think hes ever made a run at a dragstrip. So thats in my favor as well.

I agree with Gofer, especially as to why most people haven't commented, I was poking at the RX7 hoping someone with real experience in one would chime in, I know the RX8s aren't great, but I've only HEARD about rx7s.

The only thing I ask is that you post back and let us know the results, for better or worse!

Oh you can count on it, im going to record it and post it one way or the other. Its a win no matter the outcome since its against my best friend and either way were going to have a good time..so long as his apex seals stay put and my 3 bolt rear takes the abuse.

 

[10's or bust]

Can't wait for the results bro

 

[gofer]

Seeing 40.9lb/min airflow at 22psi. It has been years but I have made a few passes at ATL Dragway. I dont think hes ever made a run at a dragstrip. So thats in my favor as well.

Without turning this into a debate thread, every number you're throwing out of your logs in ECMLink are all estimates and based off the accuracy of the tune. I can make a t25 log 40lbs/m and a 35R log 28lbs/m by bass-awkwards tuning it still hitting target AFR's and tricking Links airflow calculations. (You can check their accuracy if you have a MAP sensor logging boost) Same goes for the HP/TQ calculations since these are based off of the weight/gear settings that are loaded in the software and even if these are 100% accurate you can skew the log readings by doing a pull uphill or downhill.

The 70-90 time and mod list is what I'm basing my 13.5 @ 100mph guesstimate from and even that's not accurate since I'm taking your word for it and in racing sometimes 1 + 1 = potato so who really knows?


All that aside I hope you kick his ass and take home the wings, 30 rack, and tank of gas out of the deal.

 

[RipperXX]

Well I'm aware of the garbage in garbage out on the estimates. They're as good as I can get them at the moment. I do want to log the boost, but without stimulating the narrow band I don't have an input available at the moment. I want to eventually switch to speed density so that should give me an input available if im not mistaken to log the MAP sensor. There is a small error in the MAF Comp, but right now im not wanting to change anything since its running as well as it is. It pulls, harder than it ever has.


BTW, it/I ran a 13.9 years ago days before deploying to Iraq with a blown head gasket and virtually no tune. And it didnt pull nearly this hard. I think I can lean it out to 11.5:1 on pump gas, I get .4* of ignition retard, which since its near 5500rpm and was happening about every other pull or so, so I didn't think it was phantom knock and set the target to 11:1 and it went away. But I figure a few gallons of VP 110 or xylene and I should be good to turn up the boost a few more pounds and lean to 11.5:1. But won't know for sure until I make the pull..I may leave A/F alone just to be more conservative since right now im doing repairs on my house and really cant afford to blow something. There's going to be a lot going on having not been to the strip in years, they're doing some silly "legal" street racing thing now instead of normal test and tune, so I duno how that's going to be different, trying to log the run as well.

But for all the above, pretty sure its capable of solid 12s. That error in the mafcomp btw, is like 1.8-2ish psi depending on rpm. I estimated vehicle weight by starting at stock weight and just deducting the delta of lighter parts or removed parts. Don't even recall it without firing up the laptop and looking at a log though. Not sure if I accounted for my weight added to it though, I don't think I did since by default I think it has stock vehicle weight plugged in, I'll look tomorrow. Tire diameter hasn't changed much over stock but has a small amount, I think its 225/45/16s on the RX7 wheels, may have been 50s though...another thing I can double check tomorrow. I see nothing to gain by trying to fake shit on here.


ETA: Apparently it was 225/50/R16 not 45..knew it was one of the two.
Also vehicle mass is set to 2900lb.

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[gofer]

In my experience of self tuning (if you're looking for any advice in the matter) is leave your tune alone if the car's pulling hard and everything looks good, i.e., IDC's, AFR's, knock, coolant temps, etc. I seem to have my better track days by only playing with my two-step setting after each pass and trying to hit my shifts, not so much worrying about a few points leaner here or 1* more timing there. I will say though, if you haven't done it yet, before you go to the track do a WOT 2nd gear pull, a high RPM shift where you would at the track (probably 6.5-7k'ish since you don't have cams) then WOT 3rd gear too. This simulates a shift you'll be making at the track and will also show you as far as load/RPM go where you'll be in your fuel/timing tables.

I see nothing to gain by trying to fake sh** on here.

I agree and I hope these last few posts I've made didn't come off as me implying that you were. I hope you run the mid/low 12 that you're expecting and you take your buddy to the bank. I just personally know the let down of going to the track expecting a time slip that my "numbers" are telling me I should get, then don't and haven't for the last 7yrs. Which is why I advise not to look at the numbers that you're seeing in the tune because there are so many more variables that come into play when your talking 10th's of a second at the track.

You might be in luck if the event the track is doing is anything like the RaceLegal street racing events my old track held. They do ZERO track prep so RWD cars have a hard time getting off the line...

 

[RipperXX]

Nah you didnt come off as attacking, more just a person who has his doubts. I get what your saying. And yeah I will likely leave the tune as is. I figure theres no harm in a couple gallons of Xylene or race gas and turning up the boost a few pounds though. Ignition timing isnt really agressive anyway and as I understand it, with 16g setups theres a lot more to gain from more boost vs ignition timing.

Also yeah this track is know for excellent prep...on "real" events...the kind that are on T.V., but meh (at best) prep even when they were doing the test and tune events, cant say that I expect it to have gotton better, if anything with the "legal" street racing, id wager worse . AWD and full on drag cars seem to do well at this track but RWD street cars spin and spin. Seen plenty of Mustangs and Corvetts that SHOULD BE about 2-3 seconds faster than they are there.

I'm positive he has the hp advantage, I just don't think its going to be enough for him, so long as I do my part. Ever since his RX7 was built its been that car that sits and only gets driven on perfect weather to somewhere like a car show etc. He daily drives a 2015(I think) Challenger R/T. Sticky tires, exhaust and an air filter being the only mods. Its a nice car...for cruising and looking pretty, but thats it imo. He actually asked which car I wanted to run...I had to bite my tongue so I didnt come off as an ass hole. Just said the 7s faster right? "yeah", well...that one.

So anyway I guess we shall see if I'm correct in my assumptions and measurements soon. I wish I still had the gopro I sold years ago, but it just sat around doing nothing. So cell phone video and time slips it shall be.


Thanks for taking a genuine interest Gofer.

 

[Teezy]

He has one of those spinning triangle cars...a 93 Rx something...duno what the prescription is for, maybe it needs a pill to get going?

Anyway its had a single turbo swap FMIC, 3" exhaust, duno what the fuel upgrades are but I remember theyre adequate, I want to say hes at 17psi of boost on pump gas, I forget what hes using for tuning. Supposedly the guy that rebuilt the engine, did the single turbo conversion and tuned ir for him xlaims 400hp, duno if thats flywheel or wheel..I do remember it pulls pretty hard.

Just pretty much FINALLY got my car where I want it...only took 14 years or so...thanks to Uncle Sam interfering..abd getting married...and having 3 kids. So its been a long tiring journey. But from what Im seeing of my 70-90mph times (2.3sec) and Links hp estimates at 22psi on 93octane (330) it looks like it ahould be a sub 12.5 second car. I wont know for sure if it is oe if I can launxh and drive it well enough until we heas to the strip, but a tank of gas ans dinner was wagered and accepted.

So beer, wings and a tank of gas is up for grabs. Either way it will ve a win regardless getting to drag race an old close friend. Only thing that stands in the way..is the wife doesn't know anything about it yet...

There is a drag strip in Atlanta? I would like to watch this race.

 

[RipperXX]

There is a drag strip in Atlanta? I would like to watch this race.

It's called Atlanta Dragway, but it's in Commerce... Almost done with the current house repairs. So reguardless of how this plays out it looks like I'll have a little play money in the next couple weeks so if I lose, there may be a rematch soon, if I win...I may do upgrades anyway...just different ones. (speed density conversion, build an airbox, log MAP sensor etc.)

 

[RipperXX]

Made a list of final checks today and a few minor changes, main 4 things are a hasty intake heat shield..to later be made from stainless steel, change rear differential gear oil, dilute coolant to 70/30mix (currently 50/50) and find some about 5 gallons Xylene. Contrary to what I lnow I should do, I'm going to change target A/F ratio to lean it out just a tad (11:1 to 11.2:1) And see if I can get away with 25psi on the DIY race gas, mix should yield approximately 105 octane. Just going to slowly raise the boost on the way to the track and look for knock in 3rd gear pulls. If I can reach 25psi with none then that will be the settings for the race.

My friend and I haven't decided if we're going for multiple passes, quickest E.T. wins or just good old school drag race. Don't expect great video..its proba my going to be my cell phone duct taped to the passenger seat .

 

[gofer]

Here you go man, I fixed those links too. Thanks for the report.

1G DSM Drag Race Setup​

 

[Vegas Smith]

This is really the type of race a DSM was made for. Low to moderate power levels with street tires and a launch. Just get the launch down pretty decent and he'll run out of time trying to catch you. I remember long ago I put 10 cars on a low 12 second ls1 off a light when I had my 16g. Basically, it's much easier to launch an AWD car and it's also more effective. It's really on him to drive perfectly.

 

[RipperXX]

This is really the type of race a DSM was made for. Low to moderate power levels with street tires and a launch. Just get the launch down pretty decent and he'll run out of time trying to catch you. I remember long ago I put 10 cars on a low 12 second ls1 off a light when I had my 16g. Basically, it's much easier to launch an AWD car and it's also more effective. It's really on him to drive perfectly.

Well my friends a no show, he's shutting everyone out of his life due to some real heavy shit happening over the last year and a half my heart goes out to him.

BUT I'm here, passed tech easy, put 5 gallons of 104octane unleaded in since that's the highest unleaded they had (Wtf!?)

So laptop battery is on the fritz no idea how much life it has so it's sitting in sleep mode, stutter box isbset to 5500rpm haven't touched the tune yet so it's still 11:1. But I did give the MBC half a turn. So we will see what happens, it's a sportmans tree...and there doesn't seem to be anything slow here. Pretty much everything here is hauling ass.

 

[RipperXX]

And then this pulls up in the staging lanes..

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Everything else is hellcats, CTSV's, Corvettes, Grand Nationals, etc.

 

[RipperXX]

Well just ran a 13.4 @105mph with a 1.9somethung shit 60 foot.

Is seeing knock on the stutter box normal? 10* but never saw but .4 blip here and there during the actual pull.
Adjusted A/F to 11.2 and nudge the MBC knob just A hair...probably won't make any noticeable increase. Gauge showed a peak of 22.7ish for boost.

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Maybe I shouldn't have but I bumped the stutter box to 5750...was 5500.

 

[RipperXX]

Damn cleanup on the track is over an hour. I'm going to be pissed i can't get another run in.

 

[1990TSIAWDTALON]

Race the TRUCK!!!
Sorry to hear about your friend. Make the best of the night. You are running about where I did on gasoline. Hope you get another run in! I do my share of "playing" with my sleeper and quite enjoy it!

 

[RipperXX]

Nope, someone oiled the track down real real well... the announcer informed all drivers who got 2 pass's or less in the next even was free of charge... yay.... How about refund half my money.

Issues:

• Waste gate is still to small, causing me to undershoot the target boost and let it creep to where I want.
• 1G BOV is leaking boost at this point (23psi) which I guess is making more work for the turbo and heating the charged air more.
• Stutter box appears to have been to low as it bogged slightly (5500rpm dropping to 3500ish best I recall without referencing the log)
• Driver mod needed
• Really should get around to checking the head studs since I never re-torqued them after install and a few heat cycles.

Other than that, I'm pretty happy with her, I have the stuff from ECMLink to setup ECU controlled boost, but I got to get that waste gate shit straightened out first. And I'm tempted to convert it to speed density just to gain an input so I can log boost. I'm pretty happy with it considering the above, I think with a little more refinement and resolving the above, and mostly get my butt in the seat more, she will have a 12 second time slip before long. The 3 bolt rear worries me though, just how much abuse can they take? I forget but I seem to recall they don't like hard launches once you start to get above 300whp? Am I flirting with killing it?


THE BREAD TRUCK
4cyl compound turbo diesel. I think it ran a 15 something, the guys that own it are still tweaking on it, they said it's setup pretty conservatively at the moment, trying to ease it to it as last week they went straight to kill mode and blew a head gasket. Apparently going from 60psi of boost to 90 is to big of a jump .

P.S. It was faster than a lot of Mustangs that showed up.