actual results
04-11-2021, 05:45 PM
#2
somewhat satisifed with the numbers, keep in mind this is a 2000 camaro with a t56 9 inch, 247/261 cam.
so the good stuff is the numbers arent too shabby for a 9inch car. the tq curve and number are actually slightly above average considering cam size. the tuner brad spent tons of time with it on the dyno and feels its 99% what can be done. the driveability may need touched up. he said the gen 4 ecu is way faster, easier to tune, and driveability is easier to get with those. not saying thats an excuse cause its not horrible. actually i can cruise in 6th at 1200 rpms and it has basically 0 surge at 10%ish throttle. its the cruising in 4th around 17-2200 rpms where it needs work. so that can be done later.
the bad is something still isnt right. no way should it be falling off where its at and no way should it be peaking where it is. right at 5700 is where power stops climbing and tq starts falling so solve that issue and we clear 600. pls no suggestions right now until we address exhaust. literally we have made 65 pulls with this so all angles have been checked. power starts to fall, airflow stops rising, fuel levels off and matches airflow. map kpa is 98. something around 5700-6000 and stays steady til time to shift, its SD and pulling filter only made 2 more hp.
so at this point it has to be exhaust related. it is 3 inch collectors to a not the best y pipe, flowmaster merge, 4 inch dynomax bullet, then dumped. when exhaust was dropped and added extensions it made under 5 more hp and curve stayed the same shape. so goes back to somehow we need to make an x-pipe for this thing. i know the vette exhaust is darn near perfect, could getting a real well done x pipe on this thing really shift peak up a few hundred as well as stay flatter?
so the good stuff is the numbers arent too shabby for a 9inch car. the tq curve and number are actually slightly above average considering cam size. the tuner brad spent tons of time with it on the dyno and feels its 99% what can be done. the driveability may need touched up. he said the gen 4 ecu is way faster, easier to tune, and driveability is easier to get with those. not saying thats an excuse cause its not horrible. actually i can cruise in 6th at 1200 rpms and it has basically 0 surge at 10%ish throttle. its the cruising in 4th around 17-2200 rpms where it needs work. so that can be done later.
the bad is something still isnt right. no way should it be falling off where its at and no way should it be peaking where it is. right at 5700 is where power stops climbing and tq starts falling so solve that issue and we clear 600. pls no suggestions right now until we address exhaust. literally we have made 65 pulls with this so all angles have been checked. power starts to fall, airflow stops rising, fuel levels off and matches airflow. map kpa is 98. something around 5700-6000 and stays steady til time to shift, its SD and pulling filter only made 2 more hp.
so at this point it has to be exhaust related. it is 3 inch collectors to a not the best y pipe, flowmaster merge, 4 inch dynomax bullet, then dumped. when exhaust was dropped and added extensions it made under 5 more hp and curve stayed the same shape. so goes back to somehow we need to make an x-pipe for this thing. i know the vette exhaust is darn near perfect, could getting a real well done x pipe on this thing really shift peak up a few hundred as well as stay flatter?
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04-11-2021, 08:19 PM
#8
and forget about this setup, i have never seen an fbody build of any kind stay relatively flat for a few hundred rpms after peak yet all vette builds seem to just hold power past peak without dropping off.......this again raises some questions. the power number doesnt really concern me. where it peaks and how it acts after peak is whats telling me something somewhere is costing us.
Last edited by Floorman279; 04-11-2021 at 08:21 PM. Reason: .........
04-12-2021, 06:13 AM
#9
After that many runs and that many issues, why not yank the engine out and put it on a engine dyno? Take all the other "issues" away. Take any variables away from it being the car etc. I would hate to do it but it'll narrow down a lot and you can get much better data.
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jmilz28 (04-12-2021)
04-12-2021, 03:44 PM
#12
No mention of cubes, heads, injector size, and some other key variables that would help. Have you checked measured fuel pressure on these runs? All that said, you need 3" true duals stat, with the power you're already making. Even a 3" to 4" Ypipe won't flow with 3" true duals. Assuming nothing else is out of whack, that may be a big part of your issue. I tend to agree there is a tad more on the table, and also that exhaust is contributing. https://www.texas-speed.com/p-6234-t...st-system.aspx
EDIT: Just saw your build/help thread. I'd still take a HARD look at fuel pressure as well as injector duty cycle during the dyno runs. Your dual pump setup is a bit of a power hog, have you checked power feeding that pump? I would do 3 things (not necessarily in this order):
1. 3" duals
2. Keep in mind, dynos are all different and can change. Also, should really have SAE numbers. Even then, dynos are a tuning tool much more than a reliable and accurate instrument and comparing runs on different dynos is a fool's errand.
3. Call Mamo
EDIT: Just saw your build/help thread. I'd still take a HARD look at fuel pressure as well as injector duty cycle during the dyno runs. Your dual pump setup is a bit of a power hog, have you checked power feeding that pump? I would do 3 things (not necessarily in this order):
1. 3" duals
2. Keep in mind, dynos are all different and can change. Also, should really have SAE numbers. Even then, dynos are a tuning tool much more than a reliable and accurate instrument and comparing runs on different dynos is a fool's errand.
3. Call Mamo
Last edited by jmilz28; 04-12-2021 at 03:55 PM.
04-12-2021, 04:11 PM
#13
After finishing your original thread - I wouldn't be afraid to call Mamo again but I would DEFINITELY triple check your electrical (see your other thread) and fuel pressure at WOT first. You should have plenty of fuel IF both pumps are on, but that doesn't mean the pair is getting the current they need. I'd say you are definitely stretching it if you are running this on a single 250 pump. If your headlights are dimming on the dyno, your coils, injectors, and pumps are almost certainly lacking also.
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G Atsma (04-12-2021)
04-12-2021, 05:12 PM
#14
After finishing your original thread - I wouldn't be afraid to call Mamo again but I would DEFINITELY triple check your electrical (see your other thread) and fuel pressure at WOT first. You should have plenty of fuel IF both pumps are on, but that doesn't mean the pair is getting the current they need. I'd say you are definitely stretching it if you are running this on a single 250 pump. If your headlights are dimming on the dyno, your coils, injectors, and pumps are almost certainly lacking also.
anyway yea figured anybody responding to this thread would have 90% of an idea of my setup thats y i didnt post much about it just to keep the thread a little more dumbed down. will get the std numbers this weekend.
injectors are only 42s so 48ish at ls1 pressure. duty cycle is around 88-91% i think so in a decent spot. didnt wanna go any larger than necessary to help with driveability. the engine dyno theory is entertaining, to go that route which honestly is a decent idea, i would have to find a decent place in pa or de to do it. i do plan on doing a clutch swap and or magnum swap so doing it then wouldnt be a bad idea.
well obviously tony was contacted months ago. he says numbers in this chassis are decent, not sure if he is/was aware of whats its doing after peak.
everyone kept saying fuel issues months ago, however tuner is confident its not fueling. we are only running one pump which i dont remember if lonnie uses 340 or 255 pumps. so we never have turned on second pump and here is why. his words roughly, i think pressure is fine, fuel injector pulse rises at a normal rate and drops off when power drops which indicates air flow isnt increasing which means fuel pressure is maintaining. also said in your situation i see airflow level off, idc level off, all indicators of engine becoming inefficient which is what dyno is saying also.
whats just interesting is we literally made roughly same numbers upon removing the 4 inch maf housing and big maf card and SD tuned.
he didnt have any other large cube fbodies dynos to compare to but all his vette cars are dynoing roughly what every other dynojet puts them at.
the headlight dimming, i have a good original gm truck alt in there, forget what i had to look for but 99% certain its the 160 amp or whatever when i bought it. the batter however is mildly old so could be worth swapping that to see whats up. i did replace the single wire going to alt with the ws6store pigtail i think, the other wire in the big 3 is stock.
04-12-2021, 05:26 PM
#15
If you ran it with open headers with collector extensions and the curve shape and power stayed almost the same then the X-pipe will make literally no difference to the curve or overall power.
If you think something is wrong you aren't going to find it in the exhaust.
If you think something is wrong you aren't going to find it in the exhaust.
04-12-2021, 05:32 PM
#16
ok my train of thought/idea was while it may not be a restriction, wouldnt the high rpms benefit from a scavenging xpipe? maybe not a ton but on a setup like this which is moving a decent amount of air maybe it could really use some help pulling the exh gasses out
04-13-2021, 09:30 AM
#18
Performance wise, sounds like intake and exhaust aren't major issues. For my sanity, at minimum, I would toss in a new battery AND upgrade the big 3. https://learn.sonicelectronix.com/how-to-big-3-upgrade/ It's not a ton of money and your car is telling you the current flow is inadequate. Seriously, if your headlights aren't getting what they want at WOT, neither are the injectors, coils, or pump. Truck alts are a definite upgrade for normal driving, but will likely fall flat above 6k, they weren't designed to spin that high. Combine those 2 issues, and it will create a ceiling. If battery and big 3 show no difference, I'd look at replacing the alt. Also confirm if your pumps are 255 or 340, if it's a single 255, that is really a reach with your power level.
04-13-2021, 01:26 PM
#19
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