RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   Time Slips and Dyno (https://www.rx7club.com/time-slips-dyno-121/)
-   -   Dynoed the FD tonight some questions (https://www.rx7club.com/time-slips-dyno-121/dynoed-fd-tonight-some-questions-808831/)

Ottoman 12-24-08 02:43 PM

Dynoed the FD tonight some questions
 
1 Attachment(s)
After so much time and effort and money into the FD.. it's finally coming together..


Took her to the Dyno tonight for some final tweaking and tuning.. (first rotary on the bahraini dyno )

Performance related Mods are:

Fresh overhaul on the motor stock everything stock ports all new oem mazda parts(no porting no polishing nothing)

JDM UIM/LIM
Apexi Intake
Greddy/Trust SMIC
HKS twin Power
Downpipe
Test Pipe
HKS super Drager Catback
Walbro Fuel pump
Apexi AVC-R
stock plugs
stock injectors
Stock twins rich man's non-sequential with ported wastegate


Everything was done here by me and my friends.. including the overhaul of the motor and the tuning.. with the help of the service manual and the forums as our guide


Best Run of the Night was 337whp and 294 trq @ 1 Bar

the other run was the last of the night.. I was attempting to flatten the torque band.. and fix some of the rich spots.. but the dyno's WB and my WB were showing diff numbers..

I've completely maxed out my stock injectors and cannot go higher until i upgrade the fuel system


i'm still new to the whole tuning thing.. so I think there's some more potential to be squeezed out..

temp was 23* C and 13% humidity


https://www.rx7club.com/attachment.p...hmentid=325264


are the squiggles in the top end normal? is that a sign I need more tuning?

how does the graph look to you guys?

the 337 was the best run.. and the 333 was the last "most tuned" run of the night..

comments/ opinions guys?

arghx 12-24-08 05:16 PM

switch to four BUR9EQ plugs.

the "squiggles" are because he set the smoothing to 0. Most dyno sheets you see have the max smoothing on (5 I think it is). Ask the dyno operator to put the .drf files on a flashdrive for you. Then you can manipulate the dyno plots in in WinPEP, which is free from dynojet.

Ottoman 12-25-08 12:08 AM

Yeah i figured smoothing would account for it.. but wanted to see it "raw" so that i could work with it like that.. just thought it was strange that only the upper Rpm was choppy and not all the way..
although i could feel the car vibrating on the Dyno.. perhaps that had something to do with it..


but how's the power band and dyno sheet look otherwise?

mdpalmer 12-25-08 01:24 PM

Hey looks good :cool: I posted in the 3rd gen forum asking about your dyno run files... check it out:

https://www.rx7club.com/showpost.php...84&postcount=9

arghx hinted at that in his post. I didn't stare at your plot too closely, but the torque looks a lot like mine (I'm nonseq too, but making less torque/power than you). Can you comment on your boost vs. rpm curve? You say 1 bar, but at what rpm did you make 1 bar and did it stick to 8 grand? TIA :)

EDIT: BTW, my WB in the downpip and the dyno's WB in the tail pipe read different too. The dyno read leaner as compared to my WB by a bit, and the other thing I noticed is that the dyno data was sampled at a much slower rate (I have to look it up but I think it's like a few samples/second versus the datalogit's 10-100 ish samples/second)...

smg944 12-25-08 01:36 PM

good numbers. definately go all 9's for plugs. and upgrade your fuel. what are you running for an ecu?

Rixio_Scon 12-25-08 02:31 PM

As other have said switch to 9EQP plugs, stock plugs are only good for stock motors.

Thats great power. Is the engine stock or ported?

Ottoman 12-25-08 04:37 PM

Thanks for the feedback guys..

the motor is bone stock.. I rebuilt it myself..

no porting what so ever.. I used brand new housings from japan and OEM 2 piece seals.. in fact everything is new internally except the housings, rotors and the E-shaft.. I replaced everything else...

manifolds are JDM (couple less holes in it, hopefully smoother airflow I hope) if not at least it looks cleaner..

ECU is a Power FC natrually.. Tuned by me as well.. I was nervous and didn't wanna get too agressive on the timing.. so I aimed to keep knock below 20 and A/F was mid to low 11's... at the very top end it went as Fat as 10.8




Can you comment on your boost vs. rpm curve? You say 1 bar, but at what rpm did you make 1 bar and did it stick to 8 grand?

yeah I saw ur other post on the other thread..I replied there as well...


as for the boost curve..

I have the rich man's non-seq. but I didn't weld the door open... I cut it out completly and plugged the hole... and ported the wastegate a bit..and I'm still running the Stock Y pipe not the efini one (it's on the wish list tho) i've also removed the butterfly from the pipe

I have my AVC-R connected slightly diff then the usual guys.. I don't know if it makes any diff to the boost curve or max boost tho...it seemed to work so i didn't tamper with it further


basically I see positive pressure in the 2,000's

by 3,400 I see 0.5 bar

by 3,800-3,900 I See full 1 BAR.

the defi needle wobbles and waivers.. which is a known phenomenon but the AVC-R shows it as a constant number.. it momentarily creeps ever so slightly.. reach 1.05bar for a short time but it's 1 bar for the most part

boost holds till redline and doesn't drop off...

Even out of boost tho.. the engine feels peppy... anything after 2k rpm is fine for the commute.. over taking is easy and such.. even in 5th..

arghx 12-26-08 09:54 AM

there's no need to dip richer than 11:1 on your setup, I've had good luck on FD's with stock twins at that boost running low 11's. The car really seems sluggish under 11:1 AFR. The "ever-so-slight" creep could be related to the duty value in the AVC-R. I wouldn't worry about it.

jacobcartmill 12-26-08 07:48 PM

what were the intake air temps at the end of the runs? i'm curious as to how the SMIC handled the runs.

Ottoman 12-27-08 02:10 PM

the dyno I was using does not have a very strong blower..

more of a large fan that makes a "large" breeze..

so i had bags of Ice to compensate..

before a pull the SMIC would be cold to the touch... (the areas where ICE could reach that weren't blocked by the shroud) and the UIM as well

after a hard pull.. they would feel "warm" to the touch..

stock air temp location would show approx 10* change..

Ambient was about 25* C

after Icing Airtemp would be about 16


I had only 1 hr on the Dyno.. so i didn't want to waste too much time with cool downs... as I had to tune as much as possible..

I got about 6 runs in.. temps were always in the 20's...


on the street.. stock temp sensor usually shows in the 40's


I'll track the car in Jan. and see how it does..

jacobcartmill 12-27-08 02:33 PM

those numbers are pretty good. that's right at what i'd expect from those mods @14psi. you should trap about 113-115 in the 1/4.

Ottoman 12-28-08 05:15 AM

thanks dude..

i want to take her to the drag..

but my fear of breaking stuff is stopping me..

as shipping in another Diff would cost a fortune due to the weight..

(my greddy SMIC cost $140) imagine a heavy diff!

so i've been sticking to HPDE's and open track days on our F1 circuit..

tom94RX-7 12-31-08 01:05 AM

Nice hp for that boost, makes me want to rebuild my motor cause I can't make that much power at that boost level.

You need to get your own wideband and then you could do your tuning on a highway late at night. The first time I was on the dynojet, their wideband was so off, it was reading under 9.99 when my wideband was reading low 11s, so If I would have been tuning my car based on what their wideband said then my motor would be blown up cause it would be running way too lean.

Don't be afraid of the drag, I never broke anything there, stock diff. and axles. Well I do have the solid diff. mounts and other parts, but just take it easy off the start, don't drop the clutch, don't wheel hop it, and you will be fine.

Ottoman 12-31-08 02:06 AM

how do u cut a 1.53 60' if ur not launching hard? i thought the whole trick to drag WAS the good launch..

I have super pro bushings in my car and was considering getting the banzai diff brace.. some ppl say it doesn't help tho..

when u burnout and launch is there a trick to not wheel hopping?

or u're just slipping it alot off the line?

tom94RX-7 12-31-08 02:15 AM

Well ya I launch it hard, but the first year I wasn't launching it as hard, and ya I let the clutch slip. I meant that you can launch it not so hard and see how fast you can go at the end of the track. I have the banzai brace now for extra safety, but I was launching it hard without it and didn't break anything. You need traction, and those solid diff. mounts and toe links & trailing arms and you won't wheel hop, and of course the slicks help a ton. For now you could get away with slipping it alot off the line and may not wheel hop. I also put new pillow balls in.

jacobcartmill 12-31-08 12:59 PM


Originally Posted by Ottoman (Post 8837110)
how do u cut a 1.53 60' if ur not launching hard? i thought the whole trick to drag WAS the good launch..

I have super pro bushings in my car and was considering getting the banzai diff brace.. some ppl say it doesn't help tho..

when u burnout and launch is there a trick to not wheel hopping?

or u're just slipping it alot off the line?



i've never broken anything at the track either, and i've had multiple 1.8 60fts on normal street tires (my best is 1.72). I also have several friends with somewhat fast cars (11's and 10's) that run slicks regularly and they rarely break stuff.

the key is to not use drag radials. they are what make stuff break, and no one realizes this. they do provide a lot of grip, but they don't supply the big, soft sidewall to absorb that initial force, so the axles and/or diff take the brunt of the force. you can drop the hammer all day long off of the rev limiter on some ET streets (basically wrinkle wall DRs) or some full slicks and no break anything.

tom94RX-7 12-31-08 01:01 PM

I did run hoosier drag radials for a year and lots of hard launches and 1.6 60fts. Maybe those are better than most drag radials, Idk, I just didn't have any problems with using them. I know the ET streets are better for not braking anything.

BC-FD3S 01-14-09 11:56 PM

wow, that's a fat torque band. 100flbs at 3krpm and almost 200 at 4k is crazy with stockers. I'm going to have a similar set up to yours aside from a new motor, hopefully I will be somewhere similar power/torque wise.


All times are GMT -5. The time now is 02:49 AM.


© 2024 MH Sub I, LLC dba Internet Brands