Fast355

iTrader: (2)

I just burned the chip on a bolt-on cadillac brougham L03 305 roller cam engine with "187" swirl ports on it, in a 1987 chevy truck. All that was on the engine was a pair of Flowtech P#11500 headers. Stock intake, stock TBI, stock air cleaner, high flow cat, and flowmaster 50 series. We then ran it on the Mustang dyno. With the stock 305 truck ECM it made 164.7 RWHP @ 4,000 RPM and 261.2 ft/lbs @ 3,400 rpm. That corrects to 219.6 HP @ 4,000 and 348. ft/lbs @ 3,400. After programing the same untouched, nearly stock LO3 made 181.7 RWHP @ 4,400 RPM and 284 ft/lbs @ 3,200 rpm. Those numbers correct to 241 HP @ 4,400 and 378.7 ft/lbs @ 3,200 rpm. Good numbers for a stock cam, stock head, stock intake, 305.

Edit-All numbers are uncorrected. I forgot to mention it was between 90*(around 9:00 PM), 86*(around 10:00PM), and 85*(around 11:00 PM). The humidity was as follows 55%, 67% and 67%. The BARO was 30.00, 30.05, and 30.02. The Elevation in Grand Prarie, Texas is around 590 feet. That gives a correction of 1.039, 1.038, and 1.036. That gives roughly 189 RWHP and about 250 at the crank.

MikeDirntRulez

So you got almost a 40-50 HP gain just from burning the chip?


Hmmm.... wanna burn me a chip?

a mack6

iTrader: (1)

Yea that is absolutely amazing...now i know next to nothing about chip burning, but what exactly did you change/adjust that added over 40 HP???

I WANT TO KNOW!!!

jimp2001

Yeah I can't believe that so much power is held back by the computer... I'm going to burn some chips for myself... Gotta invest a few bucks and start playing around.

Fast355

iTrader: (2)

I am only getting 17 HP with my math, and around 23 ft/lbs. That is around 22.5 FWHP and 30 ft/lbs. Having headers and the exhaust changed the fueling and timing requirements from stock, which resulted in a better gain. I doubt I would have gotten as much of a power increase with a totally stock engine, but then again it is pretty detuned for smog and MPG.

I am running a PE air fuel mixture that holds very steady at 12.8:1(verified on the dynos WideBand O2). The timing is set at 36* @ 2,400 rpm in PE mode. The throttle response is awesome. The torque converter clutch is set to mandatorily lock at 75 MPH so converter slippage is practically 0 in that situation. The VE tables are set almost perfectly even up to 5,300 rpm. It is the small details that make power.

a mack6

iTrader: (1)

Alittle off topic, but i've been looking for someone whose knowledgable about TBI tuning, whose not gonna tell me to just go look at the DIY PROM stickys... After adding a 3" hooker catback, and an open element..how much HP do you think i could gain over stock with a custom burned chip??

Now those mods together should add maybe 5-15 HP with the stock tune...but with a custom tune, how much would i be lookin at..roughly?

Fast355

iTrader: (2)

It really depends on how much those changes affected your VE tables. Before burning the chip I would add some headers and a good high flow catalytic converter. That should boost power by a signifigant amount. An edelbrock intake would also help make some more power.

I can see a person gaining 8-10 hp and 10-15 ft/lbs over stock on a stock engine just from tuning it.

You might be able to see around 12 hp more with tuning, but that is a guess, not a promise. What you will see after a good tune is better throttle response, a little HP, more torque off the line, and somewhat better fuel mileage.

a mack6

iTrader: (1)

VE Tables??

Another question i had was did you modify/change all the bins (is that what they are called? am i using the term correctly) or did you only change specific bins (ex: Speed limiter). The one thing that i never understood was that on what i plan to do to my car, which would basically leave the engine stock, would i have to mess with everything, or being that the car was only mildly modded, i would only have to change certain things... If this is true, can you give me examples of some stuff that i'd have to change/mess around with???

Fast355

iTrader: (2)

Download a copy of TunerPro, find the "8746" ECU file, then find a AXKS .bin file. Start the program and look over the settings. You don't have to change much on a slightly modified engine. There are only a few tables that require recalibration. Even my Van's engine didn't take too much to get it right.

a mack6

iTrader: (1)

Alrite thanks ALOT man...those were the biggest questions ive had about making my own chip, but ive always been to imtimidated to go the DIY PROM board because i dont understand half of the stuff in the stickies and i dont wanna seem like a moron by posting little topics here and there...

one question tho...is there any way to do the burning w/o a laptop (Seeing as i dont have one)???

Fast355

iTrader: (2)

It CAN be done, but it will be a PAIN. You cannot datalog without having a laptop. Well you could use a very long extension cord and a desktop.

A used laptop that will burn EPROMs and Datalog can be had for cheap anyway.

Benm109

No, not really. You need to be able to drive the car around with the laptop hooked up so you can record data. Just idling in park won't do it.

Not having a laptop is what's holding me back from PROM burning, as well. You don't need a new or expensive laptop, I've seen plenty of great ones for sale on Ebay for $50 to $300 (although, anytime I try to save up money for a laptop, I end up spending it on another car part ).

a mack6

iTrader: (1)

Yea i'll have to see about the laptop... im sure ill get one when i go to college, but thats a year away and i dont know if i want to wait that long...and my mom actually has a work laptop, which i might be able to use, but shes trying to get a different job so she probably wont even have it when im ready to do the chipwork. Looks like ill have to get one offa ebay durin the winter....

kdrolt

181.7 rwhp/0.85 = 213.7 fwhp
or
189 rwhp/0.85 = 222 fwhp
(using 15 % loss)

284/(1 - (0.15*3200/4400) )= 284/0.89 = 318.8 fw ftlbs
(using linear loss with rpm interpolation from 15%)

I think 214 fwhp and 319 fw ftlbs seem more reasonable for a 305 with a much-improved exhaust, tuning, and no other improvements. So I think you messed up in the math somewhere because these #s are not close to 240 and 380.

Even with 214 fwhp and 320 fw ftlbs, it's excellent and consistent with a test I remember on a stock Goodwrench engine having a really good exhaust (headers, aftmkt mufflers). The data are somewhere on the web -- it was a stock Goodwrench 350 engine, with only exhaust modded. IIRC it made around 230 fwhp @ 340 fw ftlbs with everything stock other than the exhaust + revised fueling (via carb). It shows just how poor the factory LO3 (and therefore LO5) exhausts are on the Caddy and Chev uses of the 305. It also shows that the heads, however poor they may be, are still good enough to make 215 fwhp even with the so-called peanut cam.

And for the critics, even if you assume that the Mustang dyno is grossly optimistic, it's not going to be THAT far off. With that thought in mind, has that dyno ever been used to test a well-known widespread car like a stock Ford 4.6 or Vette or Fcar? And if so, how close was it's rwhp and rw torque to the dyno numbbers obtained elsewhere?

Fast355

iTrader: (2)

I was told to use 25% loss through the driveline with a 700r4. That is where my numbers differ. I think 210-240 fwhp is good regardless considering the factory rating was 170.

a mack6

iTrader: (1)

Yea that is very good. I'm only looking to get a 10-15 HP increase over the factory 170 when im finished with my mods, but as it turns out that with a custom chip i may be able to get 25-30ish i'd be thrilled. I can't wait til i can get my other mods on and get to tuning!!!!!

ShiftyCapone

iTrader: (7)

Great info. This is just another example where the power to these cars lies in the chip.

kdrolt

No question -- no matter how you factor the trans loss, 210 to 240 fwhp is excellent. That's why I included the comment for the inevitable TGO critics in my last post.

On the trans loss:

700R4 (old name) is the same trans as a 4L60 (new name). 4L60 is mechanically controlled; the electronic controlled version is called the 4L60E. Same gearing for all trans, therefore same losses at WOT (which is what you're measuring).

LT1 (as used in the B, D platform cars) typically rwhp at 215 to 220 driving through a 4L60E, as shown in numerous tests across many dynos. The factory rating at the flywheel for the B/D LT1 was 260 hp. 215/260 = 0.827, or 17.3 % loss; using 220/260 = 0.846, or 15.4% loss. I don't know what trans you were using in the LO3 dyno test, but it's not likely to be vastly different insofar as internal gearing, and therefore internal friction.

The most common assumption is that the automatic trans run 15 to 18% loss, and that the manual trans (6-speeds e.g.) run 12 to 15% depending on the condition of the trans and how slipperly the trans lube is. The only (GM) trans that I know of that routinely gets factored at the 25% loss level would be the 4L80 and TH400.... and maybe even the Powerglide (for those that remember them).

Using 25% loss, your 305 would out power the 350 Goodwrench engine (tested on an engine dyno I mentioned above) .... and that makes no sense given that the biggest difference between them is the 45 cid. So I think 25% loss is too large, IMO, and very much over estimates the engine output at the flywheel.

Fast355

iTrader: (2)

Kdrolt, it was a Turbo 400(weird shaped pan and modulator, electric kickdown) that is why I used 25%. It also has a transfer case being 4wd. I doubt the transfer case loses much in 2wd HI.

As far as vs the goodwrench 350. That engine uses almost a full point less compression and a flat tappet camshaft. Plus the heads are large chamber smog boat anchors. Also the Caddy engine uses the L-98 camshaft, like some caprices of the era. The TBI had 350 injectors from GM as well.

Edit- my 700r4 power consumption was from working with my G20. I said 700r4 but it is not. Irregardless it is the power that makes it to the wheels that matters anyway. Mustang says there is not a way to accurately calculate power at the engine from a rear wheel dyno, period, so I am thinking I will believe them. Meanwhile, I'll just guess at the engines true power.

kdrolt

No pass car TBI LO3 used the L98 roller cam. I didn't know that Caddys had LO3. I thought they got the 4.9 TBI alum v8 engine up to 1992 and then it was replaced by the TBI LO5 for 1993. i.e. no LO3, and I doubt they ever used the L98 cam (773 part number suffix). So did you use the L98 cam or the peanut (stock) LO3 roller cam?

Understood on the TH400. Interesting.

And I agree that rwhp is the only thing that matters UNLESS you are trying to compare to a factory benchmark (where there is no rwhp, or even track metric available). You've done most of your work on the chassis dyno, with a little at the track and almost entirely in trucks. That makes it hard to compare with any factory numbers or with passenger cars.

JPrevost

correction factors; 1.041,1.037,1.036

http://www.eng-tips.com/viewthread.c...=116240&page=3
That link explains a lot if you think you can through around numbers as you please to back your assumptions of engine horsepower. Too many variables and not enough data even with the dyno correction values. The only thing you can say is that you picked up X amount of rwhp after applied corrections. THAT is enough for me to say good work. What takes away from my praise is posts that include the drivetrain as a % of loss. I posted a thread up a while ago that showed how wrong that assumption is and read the link above if you don't believe me.
https://www.thirdgen.org/techbb2/sho...hreadid=275789
I even tested the pumping losses and drivetrain on a DC electric dyno and guess what, the power loss was a fixed torque, not %, when kept within it's design specs (not overloading it with a billion ft/lbs).

http://www.chevyhiperformance.com/techarticles/46320/
That's the link to the Goodwrench 350 dyno testing. It's a more powerful engine because the heads flow well for the extra cubes. A perfect example of why a 350 is worth more to everybody than a free 305 . You just have to rev the 305 that much higher to move the same amount of air/fuel through the engine. With higher revs comes more heat and pumping losses hence the reason for drag racers to use the "no replacement for displacement."

So to kdrolt; you are a false. You think you know what you're talking about when infact you are using "Hot Rod" magazines as your "proof" that I am wrong. Yes, I went there, I called you false. I'd like to hear you dig yourself out of this one as your last post was very entertaining to share with my friends. We had a few drinks over it and the conclusion was you are a waste of my time. I personally didn't think so but I guess they were right. So consider this my last personal reply to you. Now you can go ahead and say whatever you want, I won't even try and to defend myself.

Fast355, you said the caddy L03 got an L98 cam of sorts. Well if that's the case, take a look at this post. https://www.thirdgen.org/techbb2/sho...hreadid=188413
It's similar but don't go comparing it to your numbers for the following reasons; Who knows exactly what cams are in which, there are various "L98" cam profiles just like there are Lt1 cams. Then there's the driveshaft, the transmission, the actual dyno, the correction values, the tire profile and rolling resistance, the actual rollers (double pinchers aren't good for tires), exhaust differences, intake manifolds, fuel injectors, ecm's, calibrations, rear gears, rear in general, wheel weights, etc. As much as people want to put down the dynojet compared to the mustang, I consider them both great so long as you stick to the same one and use REAL correction values (your's were within 0.002 of mine) . There are more considerations to be made that people don't want to look at as being a factor when in reality it is. Things like your driveshaft weight, rear gears, pinion to ring angle, rear gear teeth angles, tire profile height, double vs single roller, heat soaking without proper fans up front, engine temperature, and fluid levels ALL effect the actual power that gets to the ground. My professor at school showed me a graph of the power lost as heat on a ring and pinion gear set with varied pitch angles and then vs position. From that day forth I've tried to eliminate as many variables as possible and prohibit myself from comparing 2 different vehicles to eachother for hp numbers. It's just not fair to the engine, let alone the casual reader to be comparing horsepower numbers with so many variables being unknown. As for the transmission loss, the th400 definatly sucks up more power so I'd say you've done well with your progress JUST from looking at the big picture but mostly (90%) looking at the stock dyno vs after your tuning. That to me is all I needed. I'll leave kdrolt to come up with some engine horsepower numbers using his "engineering" practices of filling in the gaps. I only that I know my car has a similar drivetrain to others on this board and I'm trapping some decent speeds. So I only go as far as saying yes, I'm putting down more horsepower than stock . I've seen some thirdgens post 40hp more than the next guy but trap slower and get a slower ET with the same 60', go figure.
Good luck with the tuning if you're going to do more. Look at a good torque converter as a future upgrade. The $800 units can recoop the costs in gas saved if you tow a lot or drive lots of miles in the city. Also, the intake manifold could be improved with a performer with carb adaptor. The extra plenum volume is good for flow through the stock TBI. Other than that, might look at going to a newer pcm but that might not gain you much. In the end, you've proven gains and for that you should be very proud! Continue the good work.

edit; That's the smartest thing I've ever heard you say.

Fast355

iTrader: (2)

I said it was a stock 305, which it is. I am not decieving anyone. It wasn't the peanut cam but it was the swirl ports. It is a stock L03 vin E out of a 1991 Brougham. When the carbed 307 died in 1990, the TBI small block Chevy replaced them. The 1991-1992 Brougham came standard with the LO3 and optional with the L05. Both came with the 773 cam, I also believe the caprice 9C1 came with the L-98 cam even when equiped with the 305 or the 350. It is definately the L-98 because the specs in the service manual for both engines shows the same lift specs and the cam had 773 stamped on the snout when we changed the timing chain. It was definately a stock engine as it came out of my grandpas 1991 fleetwood brougham(it is being replaced with a 400 TBI). It had 350 injectors in it from GM as well, how do I know? The BPWC in the cadillacs ECM was 125 instead of the normal 148.

http://market.autopartsfair.com/cadi..._694ioy_8.html

I wish I had the money to switch to an edelbrock intake and a larger TBI. I don't right now and my bored intake and 454 TBI are on the G20. I can't have both down at the same time.

JPrevost

I haven't found a single 5.0 L bin with a ~148 bpw. They're mostly 135, are they different in the 7747? I'll look later but I could care less . The injector size is approx 58# and most "350" injectors were in the 62-68 size with the 305's being between 52-58.
Fast, could you send me the stock bin? I didn't know the Caddy used an 8746/7747 in 91-92, learned something new today .

Fast355

iTrader: (2)

The ECM had a different part number, can't remember it exactly, seems like it was 1228036.

kdrolt

That link, for the benefit of everyone here, is a discussion about extrapolating fwhp estimate from rwhp measurement, and JPrevost is suggesting that one of the writers within the thread (Harold Bettes of Superflow) has the last-word final-answer on the subject. I intend to write to Bettes so that his comments in the above thread are not taken out of proper context in JPrevost's argument with me.

Interesting that Prevost should showcase Bettes' post when

(a) Prevost doesn't think Superflow makes good equipment
("Also, if you want REAL flow numbers with heads you need a better test bench than a "superflow". They're really useless when comparing heads to one another."

and

(b) that there are other threads, with MUCH more detail, on the www.eng-tips.com website that offer BOTH sides of the argument. One in particular on that web site deals directly with Transmission and Driveline engineering. JP neglected to post those links.

You used a hand waving argument, no physics, no math. Not a very good showing for a Mech Engr student. I gave you the right answer but you still don't get it. In that thread JPrevost offers his views, and I offered mine. Here's an excerpt

from JP:

The recurring theme is that JP says so, so it must be true.

In my argument, I used an engineering approach via math based on sliding friction problem. The work done in a sliding friction problem can be converted to the power loss. It leads to the idea that power loss (in the driveline, which includes geared components like the transmission and the rear end) is proportional to rpm, and proportional to load (input power from the engine). It's starts from first principles (free body diagram) and is then developed into work and power relationships.

So JP's argument is that he says so; mine is based on physics, engineering & math.

To save me from typing, and to allow everyone to see both sides of the argument from another group, look here:

http://forums.corvetteforum.com/show...0&page=1&pp=20

It's a five page discussion, and it offers most of the usual arguments. How it differs from most is that there are several MEs (ones that have actually finished college, remember much of it, and that actually went to the trouble of citing actual physics & math). Look carefully at the comments made by Terry Humiston and SWCDuke. Humiston offers a viewpoint that's close to mine, SWCDuke offers one that differs. They don't agree.... initially.

Page 4 is the most interesting because closure occurs, wherein several people agreed with what Humiston view, and the punchline was driven home by ZeeOSix when he quoted "Elements of Machine Design" by Kimball and Barr.

The drivelines power loss topic has been discussed elsewhere on TGO before, it's not a new topic. This thread

https://www.thirdgen.org/techbb2/sho...hreadid=289640

is one of many, and it also has both sides of the argument. RB83L69, a person I have disagreed with before on other subjects, has IMO the most concise and detailed answer, with ME Leigh closely behind. I agree with both of them. There are also opposing views by two moderators.



JPrevost knows that torque*rpm/5252 = horsepower, where torque is in ftlbs and hp is hp. So if the torque is constant (fixed) with rpm, per JP's own words, then testing over a wide range of rpms gives a linear increase in power loss as rpm increases ---- which is the exact math I used to derive Fast355's estimated fwhp. Thanks for unwittingly demonstrating my math JP!



Yes, I do think I know what I am talking about. I have a BSME (you don't, yet). I went to grad school and got the same degrees that your professors at OSU have. I don't advertise that here but you're giving me a reason to. I know the material on the same level that they do. I don't show ALL of that here on TGO because I'd lose people --- but I use enough of it when needed. You don't. This discussion, and the several that preceded it, are proof enough of that.



I cite magazines here on TGO because there are people here, including me, that read them. I seldom cite Taylor, Heywood, Mackerle or SAE techical papers because I might be the only one at TGO that owns them, nevermind can read & understand them. But if you do search for those names, I'll probably be the one that posted them, not you.

JP, they don't use hot rod magazines at MIT (where I went to graduate school and got my masters and PhD --- verified by anyone doing a library search there) as part of the graduate engineering curriculum. I doubt they do it at Princeton University (you have people you can ask about this), and I know they don't do it at the Ohio State University (because I know several people who came out of there).

All of them, however, use math a lot. They also use systems analysis, and they often take measurements using data aquisition systems. They try to reconcile (make agree) the math with the data, even if they have sparse data (which is sometimes unavoidable), to give them confidence in the math and so that they understand what is occuring. I know that because I've been there, I've done that, and I still do that for work (for MIT).

As far as digging is concerned, it should be obvious that you're the only one that needs a shovel.

Finally, there are many papers listed at the SAE web site, http://www.sae.org including the SAE paper 750924 on the Borg Warner T-50 overdrive five speed that SWCDuke cited and summarized. Those papers, plus many more that I won't list here (I've wasted enough time), plus several done at Southwest Research Institite (SWRI), are enough to settle the dispute.

The following paper also gets good reviews for it's coverage of drivetrain losses because they specifically relate to how to correct rwhp to fwhp:

Listening to the Voice of the Customer: Inertia Dyno Horsepower Versus Oem-Rated Net Horsepower, by R. A. Smithson and J. J. Carter - Southwest Research Institute
http://www.sae.org/servlets/productD...D=2002-01-0887
It was probably the prototype for Marlan Davis' dyno article.

To put this back on the rails, rwhp from a dyno measurement can be estimated back to the source at the engine. It's not a requirement to do this, as everyone already knows, but it is useful for comparison with the stock engine ratings. Drivetrain losses have been used by the big Three since the 1960s (or earlier) before a car model gets built so they know what to expect for performance & economy. That type of system modeling (of the entire car) still gets done today, only with bettter models and with computers, even by professors at OSU. Driveline loss is well understood even if it doesn't seem so here, especially when you hear it from a self-proclaimed (but erroneous!) "expert" that says


This little lesson is short and simple. Transmissions don't suck up a percentage of horsepower, it's a fixed drag with the only variable being speed. So forget all that 20% drivetrain loss, it's not a percentage!,

and especially as it relates to the Thirdgen, where the drivelines are basically the same, and the transmissions are limited to a few different automatics and manuals.