Hey guys, update: I finally got all the details worked out for the car, and I should be picking it up September 5th! Finally going to be joining Team Fiero. Going to be an interesting change, going from Team Trans Am to Team Fiero. Looking VERY forward to this though, the Fiero is one of my top 10 dream cars (four of which are pontiacs).
Stroke has very little to do with the ability of street engines to "REV" its has everything to do with airflow and camshaft timing, Neither of which this platform is designed for. What will happen, is with an identical top end, the lower displacement engine will achieve peak power and torque at a higher RPM. This has been proven time and time again the dyno.
Wear and tear is a factor, but it's affect on power production, as far as street engines are concerned, is effectively nil.
My point is, there is rarely ever a reason to not go with the maximum displacement possible. it makes reaching the desired power goal much easier, since engine speeds can be lower to achieve the needed airflow for a certain power level, provided you have the top end airflow (read: mass-flow) needed to reach that power level.
If I may jump in here.... I have a 4.9, now, with the Allante intake setup. I have considered doing a 4.5, simply for the reason that the 4.9 has all of that torque, way down low. Hoping the 4.5 could shift everything up higher. (The 4.9 isn't called a "tractor motor" for no good reason.) Your statement above makes perfect sense, though. And I believe the 4.x lower end, if balanced properly, is more than up to the task of spinning 6K or better. IF it could be fed enough air.
This premise is further precipitated by the crappy gearing available with most Getrags or F23s. Probably the most popular manual tranny options in use. Yeah... I get it. The ratios suck for a "tractor motor", but it's still a lot more fun to drive than the automatic. Seriously... Thanks for your input and information.
Hence why the Allante intake makes 20 more HP on a 4.5 than the TBI intake.
Are the TBI and PFI intakes essentially the same casting but with injector bosses in the PFI intake?
Has anyone actually done before/after dynos on a 4.9 with the PFI intake and Allante intake?
Edit: The TBI 4.5 made 180 HP while the Allante 4.5 made 200, right? The PFI 4.5 still made 180 HP, right?
Missed this... I don't know of anyone who has made back-to-back measurements on a 4.9 Allante setup. There is a dyno shop not too far from me. I might have to suck it up and go, if they'll take my car. It "feels" fairly well sorted, although I've never had a "pro" tune done on it. (OTOH, I've seen the results of a few "pro" tunes, that were perpetrated upon unsuspecting users. I can do better. Seriously.) With that said... They are a Nissan shop - specializing in 350s and 370s - so I'll probably get laughed at.
[This message has been edited by Raydar (edited 08-22-2020).]
This premise is further precipitated by the crappy gearing available with most Getrags or F23s. Probably the most popular manual tranny options in use. Yeah... I get it. The ratios suck for a "tractor motor", but it's still a lot more fun to drive than the automatic.
The ratios are terrible for just about any engine combo. They sit somewhere In between a close and wide ratios, with a very high 1st, no matter the transmission choise. Standing starts are the worst. But if you stay out of first the f23 is probably the best option behind this engine in my opinion.
Here is a Thrust chart I made of the 282 vs the F23, with a sample power curve I made up (based off of the two dyno graphs I could find online
Never checked but my trans is probably the 440 from the '88 Eldorado the engine came from. I don't like the shift points all that much for performance. It's ok for normal driving.
Heres a photo of a carbureted 4.9L (with a 2 barrel) dyno. It belongs to Arns85gt. It shows a lot better top end the the other dyno I referenced, which was Lous_dias. Not sure what was done to either engine but i believe lou_dias had a allante intake, which has extremely long runners relative the standard TBI manifold, and his tune was pretty rich up top.
Heres a photo of a carbureted 4.9L (with a 2 barrel) dyno. It belongs to Arns85gt. It shows a lot better top end the the other dyno I referenced, which was Lous_dias. Not sure what was done to either engine but i believe lou_dias had a allante intake, which has extremely long runners relative the standard TBI manifold, and his tune was pretty rich up top.
Here's a thrust curve with carb'd engine numbers.
I finally tuned it...
Ended up with 196 rwhp before they made some changes to improve idle and we settled where it is in the video... E85 fuel but heavy wheels.
I finally tuned it... Ended up with 196 rwhp before they made some changes to improve idle and we settled where it is in the video... E85 fuel but heavy wheels.
Pretty cool! That's actually about what I'd expect from an otherwise stock 4.9/Allante setup.
quote
Originally posted by FieroWannaBe:
From the looks of it, if both engines have factory cams, it looks like the Allante intake does shift the peaks down about 1000RPM...
I actually never thought about that aspect of it (as opposed to absolute peak power and torque) but it does make sense.
[This message has been edited by Raydar (edited 08-25-2020).]
If you look at my A/F graph, they tuned me down to 13:1 at around 3600 where as I personally kept asking for 14:1. It should have broke 200rwhp @14:1. E85 doesn't ping like regular gas so it's ok to tune it leaner and meaner. These 'classic' tuners haven't gotten around that in their heads yet...
If you look at my A/F graph, they tuned me down to 13:1 at around 3600 where as I personally kept asking for 14:1. It should have broke 200rwhp @14:1. E85 doesn't ping like regular gas so it's ok to tune it leaner and meaner. These 'classic' tuners haven't gotten around that in their heads yet...
I had always been under the impression Rich Best Torque wasn't affected much by E85, so if peak power is at 12:1 or 12.5:1, AKA Lambda of .85-.82, you tune to achieve the same AFR reading on the dyno. Almost all tuners do not rescale their graphs for fuel types (stoich on Gas is 14.7, on E85 it is 9.76) Oxygen sensors are blind to fuel type, they report voltage vs lambda, the numbers reported are scaled typically for the fuel type i.e. gasoline. The benefit of E85, is its octane rating, allowing for more timing, at the cost of EGT's since the flam front propagation is slower.
The textbook chart for a "typical" relationship of Lamba. It will vary based of efficiency of design and flame front speeds, which is affected by a laundry list of variables.
Correct me if I am wrong.
*edit: I believe this chart is in % Mass ratio 6.8% mass ratio is stoich for gasoline
[This message has been edited by FieroWannaBe (edited 08-25-2020).]
I had always been under the impression Rich Best Torque wasn't affected much by E85, so if peak power is at 12:1 or 12.5:1, AKA Lambda of .85-.82, you tune to achieve the same AFR reading on the dyno. Almost all tuners do not rescale their graphs for fuel types (stoich on Gas is 14.7, on E85 it is 9.76) Oxygen sensors are blind to fuel type, they report voltage vs lambda, the numbers reported are scaled typically for the fuel type i.e. gasoline. The benefit of E85, is its octane rating, allowing for more timing, at the cost of EGT's since the flam front propagation is slower.
The textbook chart for a "typical" relationship of Lamba. It will vary based of efficiency of design and flame front speeds, which is affected by a laundry list of variables.
Correct me if I am wrong.
*edit: I believe this chart is in % Mass ratio 6.8% mass ratio is stoich for gasoline
Isn't it funny that 14.7 - 34% = 9.702 ... It's all in what "scale" you want to report on. Yes we added a bit more timing... But the bottom line is no matter how you scale it, if your injectors ECM/PCM can supply fuel fast enough, running a little rich only helps with snap throttle acceleration, not WOT. Leaner is meaner. When you are at WOT for more than a second you are losing power by being rich. You can prove this to yourself on any dyno...which I've done year after year after year. When I switched to E85 and fixed my engine code, I was running at 19:1 for a month. It didn't blow up. I tuned it and it made more power being closer to stoich. For what it's worth, the E85 pump I gas up from typically tests closer to E66...but typically, engine PCM's designed to run a variety of fuels have a fuel sensor which tells the PCM how scale and adjust the fueling.
If I was the one running the tuning software, I would have left with 14.0 a/f across the board. Early on we got it to 14.5 but it was pinging...so they richened it (too hell if you ask me)... My v6 with heavier wheels left there with 178 rwhp...and yes, it's only a 3.4L...and yes, I tuned it to 14.0:1 on E85(66)...
Originally posted by pmbrunelle: Well you can't ask someone to tune your car, and then tell them how to do it...
For me at least, when I'm told to do something, I want to do it my way!
Normally, if I'm really picky about something, I'll do it myself rather than try to micromanage someone else.
I told them what I wanted. They are like "no, trust us...we don't want you to blow up your motor". This is just the classic old-school mentality of tuners. The car ran at 19:1 for a month. NEWSFLASH - it didn't blow up.
Tuning was done with TunerCat. I don't feel like spending money on it. I am somewhat amazed no one has made a proper TunerPro .xdf file for the 4.9 yet... If someone did, I would be tuning it myself...
It wasn't worth arguing over a few rwhp when I already gained 20 over the dyno from years ago... Only trolls will crap on the dyno...and I don't care about them.
[This message has been edited by lou_dias (edited 08-25-2020).]
34% less energy density pretty much translates to 34% less available carbon and hydrogen atoms per unit of air. Its been a long while since I have had to balance a molecular combustion equation, but it sort plays out that way.
I had always been under the impression Rich Best Torque wasn't affected much by E85, so if peak power is at 12:1 or 12.5:1, AKA Lambda of .85-.82, you tune to achieve the same AFR reading on the dyno. Almost all tuners do not rescale their graphs for fuel types (stoich on Gas is 14.7, on E85 it is 9.76) Oxygen sensors are blind to fuel type, they report voltage vs lambda, the numbers reported are scaled typically for the fuel type i.e. gasoline. The benefit of E85, is its octane rating, allowing for more timing, at the cost of EGT's since the flam front propagation is slower.
The textbook chart for a "typical" relationship of Lamba. It will vary based of efficiency of design and flame front speeds, which is affected by a laundry list of variables.
Correct me if I am wrong.
*edit: I believe this chart is in % Mass ratio 6.8% mass ratio is stoich for gasoline
Let's play "How many scales can we fit on the same graph?"!
Let's play "How many scales can we fit on the same graph?"!
Snazzy plot... what book is it from?
Figure 3-1. Representative Effect of Fuel/Air Ratio on Cylinder Head Temperature, Power and Specific Fuel Consumption at Constant RPM and Manifold Pressure in Cruise Range Operation, from Operator’s Manual Lycoming O-360, HO-360, IO-360, AIO-360, HIO-360 & TIO-360 Series, 8th Edition, Part No. 60297-12, dated October 2005. Page 3-7 https://i.stack.imgur.com/tJAao.png
That took some time to track down. I first saw it and similar plots during my ICE course as handouts from the Proff.
Originally posted by lou_dias: running a little rich only helps with snap throttle acceleration, not WOT. Leaner is meaner. When you are at WOT for more than a second you are losing power by being rich. You can prove this to yourself on any dyno...which I've done year after year after year. .
I would argue this is patently false. I dare say many professional engine builders or tuners would agree with me here. Unless, of course, those nerds who does this all day are just wrong. There is no Universal number, but universally there is a richer than stoich. point where best BMEP is achieved. It may not be lambda .8 or .9, but its probably not 1.0, since no fuel injected engine will safely burn 100% of its potential charge during the duration of the expansion and combustion process at normal engine speeds. However, there are many engines that run lean of stoich, and they require careful consideration to avoid pre-ignition.
[This message has been edited by FieroWannaBe (edited 08-26-2020).]
I told them what I wanted. They are like "no, trust us...we don't want you to blow up your motor". This is just the classic old-school mentality of tuners. The car ran at 19:1 for a month. NEWSFLASH - it didn't blow up.
Tuning was done with TunerCat. I don't feel like spending money on it. I am somewhat amazed no one has made a proper TunerPro .xdf file for the 4.9 yet... If someone did, I would be tuning it myself...
It wasn't worth arguing over a few rwhp when I already gained 20 over the dyno from years ago... Only trolls will crap on the dyno...and I don't care about them.
You could always dilute your E85 with gasoline, then have the A/F retuned by these folks to 13 or whatever. Then, after you leave, you run straight E85, bringing you to 14.
If there's still easy-to-get power left on the table, it makes sense to go get it. Retuning is cheaper than changing hard parts.
It just seems like a shame to not fully exploit a hardware setup because of imperfect programming.
quote
Originally posted by FieroWannaBe: there is a richer than stoich. point where best BMEP is achieved. It may not be lambda .8 or .9, but its probably not 1.0
Lou wants to run an (I assume) gasoline-equivalent 14 AFR, so lambda 0.95. Still rich of stoich.
[This message has been edited by pmbrunelle (edited 08-26-2020).]
Originally posted by FieroWannaBe: I would argue this is patently false. I dare say many professional engine builders or tuners would agree with me here. Unless, of course, those nerds who does this all day are just wrong. There is no Universal number, but universally there is a richer than stoich. point where best BMEP is achieved. It may not be lambda .8 or .9, but its probably not 1.0, since no fuel injected engine will safely burn 100% of its potential charge during the duration of the expansion and combustion process at normal engine speeds. However, there are many engines that run lean of stoich, and they require careful consideration to avoid pre-ignition.
Like I said before, it's 'old-school' or ancient trains of thought 'to be "safe"'. E85 resists detonation better than regular gas. These old-school tuners don't have that in their heads yet when they try to tune you to 12.5 or 13.0 ... Also as I said - there was pinging/detonation at 14.5 that's why we usually do 6-8 runs with various fuel setting, I only posted the final one.... and I saw this on my V6 as well so that's why my target is 14.0 which is still less than 14.7...
[This message has been edited by lou_dias (edited 08-26-2020).]
Figure 3-1. Representative Effect of Fuel/Air Ratio on Cylinder Head Temperature, Power and Specific Fuel Consumption at Constant RPM and Manifold Pressure in Cruise Range Operation, from Operator’s Manual Lycoming O-360, HO-360, IO-360, AIO-360, HIO-360 & TIO-360 Series, 8th Edition, Part No. 60297-12, dated October 2005. Page 3-7 https://i.stack.imgur.com/tJAao.png
That took some time to track down. I first saw it and similar plots during my ICE course as handouts from the Proff.
Figure 3-1. Representative Effect of Fuel/Air Ratio on Cylinder Head Temperature, Power and Specific Fuel Consumption at Constant RPM and Manifold Pressure in Cruise Range Operation, from Operator’s Manual Lycoming O-360, HO-360, IO-360, AIO-360, HIO-360 & TIO-360 Series, 8th Edition, Part No. 60297-12, dated October 2005. Page 3-7 https://i.stack.imgur.com/tJAao.png
That took some time to track down. I first saw it and similar plots during my ICE course as handouts from the Proff.
Airplane engines, cool. I have a Continental TSIO-520-H
In my drag racing days, we used to see a bottom end torque increase with longer individual runners on the manifold. The 4.9L doesn't seem to need more bottom end but more top end. The head valve size and ports were designed for bottom end torque. While I woud expect the Allante intake to give a power increase, I'm not exactly sure what the result would be in the 1/4 mile. IMO gearing may be more important.
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