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very low numbers on a mustang dyno?

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Old 08-01-08, 07:44 PM
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very low numbers on a mustang dyno?

brought the car to have it tuned and ran into some problems tuning out my 10.8-11.3 afrs at idle/low loads. afrs under wot were still alittle rich. they did 2 pulls till 5000k. first pull showed 400whp and 600wtq, they said sometimes they get rediculously scewed numbers. second pull was 202whp and 217wtq at 5k. many people claim to see 320-350 with the mods i have done. do these numbers sound legit? i would expect 300whp at the very least. what could be wrong?

15k on stockport reman
30k on rebuilt twin running sequencialy at 11 psi
stock primaries
1000cc secondaries
greddy intakes
greddy 3 row with piping
koyo radiator
pfc with datalogit
greddy prefec b
rfl bov
aluminum ast
remanned motor stock port.
efini y pipe
act clutch and 9 lb flywheel
3" dp
3" resonated mid
3" corksport catback

havent tuned with datalogit yet but that will be tuned with on friday. also doing simplified seq, might as well buy new plugs also.
Old 08-01-08, 08:05 PM
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missing my fd

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https://www.rx7club.com/showthread.p...ang+dyno+spank

100+hp and torque at 5000 over my set up with a street port and modded primary? just doesnt seem right
Old 08-01-08, 08:54 PM
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sounds like they need to get there dyno in check! i mean the numbers you pulled a stock fd pulls that.. and your modded.. its def way off!! does she seem to be a lot faster now?? or does it seem worse than stock? i say its an issue with there dyno..
Old 08-01-08, 09:14 PM
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why do you let of at 5K?
Old 08-01-08, 09:15 PM
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I never had the car when it was stock but the previous owner claims 340whp so idk what's up with it. I saw a fp green sti make 330 at all 4s right before me which kinds seemed alittle low. Idk but I'm not happy
Old 08-01-08, 09:17 PM
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they were tuning my rough idle out. I don't know why the let off but they did and 202 at 5k with my mods isn't acceptable
Old 08-01-08, 10:17 PM
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Well for one thing mustang dynos almost always read a considerable amount lower than dynojets. Most of the dyno numbers people throw around on the internet are from dynojets.

Your power is low because you stopped at 5k. There is a lot of power gained from 5k to 8k.

Also, 340whp at 11psi on stock ports w/ sequential twins is pretty high. I doubt you will see that much. I would guess closer to 300whp.

For comparison my FD's old setup was similar to yours and I was making ~220whp at 5k on a dynojet. I made ~320whp at 8k.
Old 08-01-08, 11:39 PM
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I'll be running 13-14 depending on how my fuel looks. I deffinately have enough mods for over 300 ad with the datalogit I should be able to get a pretty solid tune
Old 08-01-08, 11:50 PM
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datalogit is the only thing im really missing for my complete setup.. but i dunno if i need it personally.. but you should be over 300 or near there already! and at 13-14psi your def over 300horse
Old 08-02-08, 01:02 AM
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tuning with the commander is tedious and time consuming. The dataligit cost me what it would forthrm to fullytune my commander. I just want it done at this point
Old 08-02-08, 03:07 AM
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Originally Posted by spinnin3rd
I never had the car when it was stock but the previous owner claims 340whp so idk what's up with it. I saw a fp green sti make 330 at all 4s right before me which kinds seemed alittle low. Idk but I'm not happy
that sounds about right for a suby w/ a forced performance green. awd cars have considerably lower hp at the wheels, but are incredibly fast (until you pass them up on the highway)

+1 on not stopping at 5k, why would you do that?
Old 08-02-08, 09:22 AM
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O.P. has stated several times he doesn't KNOW why the dyno operator let off at 5K, my guess is he isn't familiar with tuning a rotary.

I have to second afterburn27 in that the previous owner's claim of 340 RWHP is a bit...ambitious...at best, a downright lie at worst.

Still though, there can't be enough said about proper tuning, which is what it seems the O.P. was going after. Shoot...we have all seen GREAT running FDs that saw tremendous hp gains once someone like Steve Kan got done with them.
Old 08-02-08, 09:53 AM
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guys they were tuning out my my rough idle. obviously they were going to do a pull to redline but they pulled fuel across the board and it didnt change the afrs at all. litterally pulled 40% accross the board and didnt change anything so they said they needed to figure out what was wrong before they could tune it. they know how to tune rotaries, the tuner himself owns an fc. supposibly you cant have o2feedback on and tune idle which knowone knew at the time so we unstrapped it and called it a day. i now have a datalogit and am going to redo all vaccuums lines so if that doesnt change anything something is deffinately wrong
Old 08-02-08, 01:34 PM
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I have pretty much the same mods as you except I have a streetport and made 317 rwhp on a dyno dynamics which reads the lowest out of all the dynos. This was done at 14 psi.
Old 08-02-08, 02:33 PM
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I would be happy with that but it's hard to belive I'm going to jump 100 plus horsepower till redline. The tuner predicted 230hp and still felt that after the pulls
Old 08-02-08, 02:46 PM
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just an FYI a dyno dynamics generally reads 10 to 15 percent lower than your actual rwhp.
Old 08-02-08, 04:23 PM
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yeah so that put you above 350 with a 10% correction factor. So where is mine going wrong? You basically have a streetport over me and slightly larger secondaries but I don't think that the extra 300ccs would have mattered. Between my mystery rattle and tiny numbers this car is driving me insane
Old 08-08-08, 09:26 PM
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3rd failed attempt at the dyno. anyone want a r1?

ive been fighting a long battle with the idle on my fd. ive done everyyyything other than re-redo the vaccum lines and replace my fpr and fuel pump which is my final step and last straw. my idles/low loads are pinned at 10.9:1-11.2:1 afrs. many members told me i had my o2 feedback on in my power fc which i did. i turned that off figuring that it was deffinately the verdict and i spent another 200$ to have my idle tuned in return of nothing. we worked on my top end and got the afrs good under wot. still not satisfied with 265whp at 7200rpms at 11 psi on a mustang dyno. now that the o2 feedback is ruled out can anyone one tell me what im looking at ?

mods:
rebuilt twins with 30k running sequencially
stock primaries
1000cc secondaries
greddy intakes
greddy 3 row with piping
koyo radiator
pfc with datalogit
greddy prefec b
rfl bov
aluminum ast
remanned motor stock port with 14k.
efini y pipe
act clutch and 9.5 lb flywheel
3" dp
3" resonated mid
3" corksport catback

wastegate flapper-washer snapped off and is causing the rattle i have posted about previously. not sure if this is an issue performance wise but just letting it be known. thanks!
Old 08-08-08, 09:32 PM
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I would need to see your maps to try to solve your problem.
Old 08-08-08, 09:39 PM
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im not an expert with rotaries so bare with me while i try to explain this.
something to do with the milliseconds at idle not allowing it to run right. we pulled more then enough fuel for it to change. i know disconnecting the o2 sensor did something because it is running worst at idle/low load then it was previously. i just hope its an adjustment or line off at the fpr. i havent got a gauge on it because i dont have a gasket for the uim. ah!
Old 08-08-08, 09:45 PM
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265 rwhp at 11 psi on a mustang dyno isn't a bad number. Do you notice the car running rich at idle (bogging down at throttle tip in?, fouling plugs?, not a smooth idle?) or is it the fact you know it's rich that's bugging you?

Now that you have a datalogit, did you save the runs when you were working on the idle?

Tim
Old 08-09-08, 07:26 AM
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i met a guy there that races with the mazda owners club and he put down 302whp on the same exact dyno with less then half of my mods, stock ecu and injectors.i deffinately know its running rich at idle. it doesnt want to let me take off and it bucks when cruising. it sounds like a cammed v8

the tunner did it on his laptop so i only have the map that is currently on my car. i could post it but people would just say those numbers are completely scewed which i know. at this point im pretty sure its a mechanical problem.

i also lose boost in first gear when the second turbo kicks in. it goes 11-6 psi fast. i would drive the thing to KDR but it would cost me alittle over... a fortune at 11:1 when cruising.

Last edited by spinnin3rd; 08-09-08 at 07:33 AM.
Old 08-09-08, 07:44 AM
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Originally Posted by spinnin3rd
i met a guy there that races with the mazda owners club and he put down 302whp on the same exact dyno with less then half of my mods, stock ecu and injectors.
Then something was the matter with the dyno that day. There is no way he got 300rwhp on the stock ECU unless he had a piggyback ECU with the stock ECU. The most we've seen on the stock ECU with full bolt-ons (including midpipe) was about 266rwhp which is still up from the 215-220rwhp which is achieved by a healthy stock FD.
Old 08-09-08, 08:29 AM
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why are you bitching and wasting money dyno tuning at 11 PSI when you want to be in the 13-14 PSI range?

265rwhp isn't bad for near stock boost. Increase the boost, and you'll increase your power (up until the point where the turbo(s) reach their peak efficiency). It's the same fact on all turbo cars. increased boost + fuel to match = power.
Old 08-09-08, 09:41 AM
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why would i spend more money to have my car tuned to a higher psi when im going have to have it completely retuned if it has something to do my fuel pressure?!


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