700r4 or T5?

 

I haven't driven an LG4, 5 speed in many years, maybe in 1983. I do remember I had to flog it mercilessly to feel like I was going anywhere. Better breathing would have helped immensely. It ran out of breath early, like 4500 RPM and just made noise above that.

 

I remember Waaay back when I had mine (it was an auto), I was lamenting to a friend's older brother (who I though knew something about cars) about the lack of power. I thought that he might have ideas as to why it was so gutless. I mean, it was a Trans AM....so...it should have been able to "decimate all". Right?
I complained about how it just had nothing above 4500 or so. My friend's older brother replied that it was a truck motor. It may not have high end hp because it was all about low end tq!

I heard what he said, but thought to myself, "Well, no....it doesn't really have any low end tq, either". And of course, it didn't.

 

LG-4s didn't come with 3.73 gears in 1983...

 

According to tech data on this forum, they did. It was option code G92.

 

Nothing much changed even in later years - the LB9 in my '86 is all done at 4500. Just makes noise above that. And that's with full exhaust, headers, an 1.6 rockers. The heads and tiny cam just can't breath past 4500.

GD

 

The L69/L98 cammed LB9s are much better. Still pulling at 5500. My '89 with L98 cam and N10 pulls strong past 6000.

 

It will certainly be interesting to see the difference when I switch over to the 350 with Vortec heads and the 274 cam. I just had the TA on the dyno again last night tuning it's new LINK ECU and the VE just plummets after 4500. The power drops off, and basically it's just not pumping any more air. The fuel curve drops off a cliff after 3800. She spins up to about 5200 but it clearly doesn't like it.

GD

 

That would interest me as well. I have a couple of Dynojet sheets from my Vortec 350. What I don't recall at the moment is whether that was with the (similar spec) Comp 268H or the XR276HR. I suspect the small flat tappet as peak HP and torque were both just short of 290. I have time slips to go with that too.

EDIT: Checking my notes and it was the 276 roller with 1.6 ratio rockers.

 

I have the G92 3.73 rearend in my car, but it came out of a L-69 car. Pretty hard to believe anyone would order that for a LG-4 powered thirdgen...

 

700R4.

It was "Dyno Day" for a local F-body forum, so I went along partially as a lark (was supposed to be duking it out for low horsepower with a '79 305 Z28), but he was having Q-jet issues, and was a no-show. My car is bone stock original, so we knew what the number was going to be. But it was nice to get a baseline before any changes.

While they were hooking it up, they were struggling to find a place under the car to attach the strap. I was trying to monitor that, give the operator my name, and tell the guy getting behind the wheel that the L03 was all low end torque, and spinning it past 4500 was a waste of time. Unfortunately, with all those things happening at once, I didn't get that message across to the driver, so we all stood around for what felt like 5 minutes while he kept the pedal glued to the floor, waiting for the engine to slowly climb to 5k or so.

I was pleased with the 144, and so no need to abuse the engine with a second run. Unfortunately, they didn't even start tracking the numbers until 3500 or so, so the torque peak was very much in the rear view mirror by then.

 

Speaking of sigs, the dumb thing is on by default and I want it off by default. Anybody know where is that setting?

 

Open your "User CP" and scroll down to "settings & options" , open "edit options" and the first setting under "thread display options" will be the selection to hid sigs . Don't forget to click "save changes" at the bottom of the page

 

That doesn't stop your own sig from populating in each post. It just hides everybody's sig so you don't have to look at any of them.

 

OK , So I thought it was the other people's sigs you didn't want to see , I know of no way to make your own sig disappear beyond simply deleting it ....

 

I only see my sig when I'm not logged in. Otherwise it's only my "details" and avatar that are with each post. You would have to select my username and explore my profile to see my sig. (And as I understand it my "sig" is the detailed description I've written about my car).
Or am I missing something here?

 

Yeah, the sig is the junk that appears below peoples' messages. Forum version of spam. I have one, and sometimes show it, but most the time I don't want to (for the sake of others).

Next time you make a post from a real computer you'll see a checkmark toggle to display your sig. My checkbox is defaulted ON, but I want it to default OFF.

 

TRUE.

This thread can now be closed...

 

Test. I will include a screenshot of exactly this post.
Do you see my sig?




EDIT: I've never seen yours on your posts.

 

Yes.

86 Sport Coupe, gunmetal grey, black interior, IROC rims, GlassTek cowl hood, 355 Gen 1 SBC, GM forged crank, Elgin rods, Mahle pistons, RHS ProTorker 170cc heads (ported by AMS), roller valve train, Comp XR288HR, Air Gap intake, 750 BG VS carb, MSD dist and 6ALbox, Canton pan, Hedman ML headers, Griffin rad, stage 4 TH700 w/10" converter, Hurst Dual Gate shifter, 1350 u-joints, 3" steel driveshaft, Dana 44 w/3.73 TracLoc, LS1 front, PBR rear brakes, Intrax 2" drop springs, Del-A-Lum/poly bushings, Spohn strut mounts/SFC's/LCARB's, UMI TA, Air Lift air bags, data logger, full AutoMeter gauge panel. 12.48/109 mph (cor.), 3450 lb.(no driver), all street suspension, 24 MPG (Imp).

 

That's because I manually turn it off most the time when posting from my computer. But it appears without choice when posting with my phone on the mobile version. I don't post much from my phone.

 

Damn. Well you learn something new everyday. I can't say I care much for my sig messing up the scene either.
And now I understand what you were talking about with the default on, etc.
I think I'll toggle that little checkbox off as I move forward. That is until someone (aka QwkTrip) comes up the answer.
PS. Did my sig show on THAT post?

 

Nope.

You can check this too by changing your settings in the USER CP to make sigs viewable. You are apparently hiding view of all sigs at the moment.

I got nothin'. One thing that does help is to make your sig the smallest text size possible (like mine shown with this post). It will make it a little less conspicuous, and provide clear separation from your normal posts. Nothing worse than an endless 15 line sig to blot out the actual messages.

 

FWIW I've never seen your sig on any of your posts. And having reviewed them back to May of this year (ten pages worth), still nothing. I have to dig for it in your profile whatnot.
Further to that, I find this website behaves differently depending on the browser. But that is probably not unusual.

 

I read somewhere that ,

the longer the sig, the slower the car

it must be true because.... Internet!

 

Well the internet never lies right?
In my case, because I'm fully aware of my vehicles limited performance, I'm just laying it all out there. Hence the longish and detailed list that is my signature. ( and I had no idea that it would be posted and re-posted, ad nauseam!) Lots of nice bits but sadly, not what it takes to be fast anymore. When I put this together having a "REAL' street car in the 12's. that was actually driveable (as in across town or across countries). had some significance. This is no longer the case.

 

Hey man I ain't pokin no fun at you. cars is cars, know what Im sayin? We all love the same thing, power, flash, show and go stands the test of time

That said. I feel you about the pain of modern day performance. 2L engines now are coming capable 500hp regularly.
It's a tough stage to race something 1000lbs lighter with 100hp extra and less than half the displacement.
gota adapt, gota learn from it. Thats why I always push to look at what the competition is doing.
displacement can be a huge advantage. Just have to learn how to use it.
Those front wheel drive, small displacement engines got nothing on a 2-step transbraked 6L at 20psi RWD w/ drag radials... thats called lunch

 

Never took it that way.
As for adapting, yeah, a racing friends daily driver is his 2018 turbo 4 cylinder Cadillac. Upgraded with the newest available parts, he's a decent match for my 5.7 litre dinosaur. Plus he gets 40+ MPG (maybe 50!) and has all the creature comforts of his living room.
That's how it goes. But I'm V8 all the way. Love the sound more than anything else. Always have. Even my LG4 with intake and headers (to get back on point here) at least had the V8 rumble.

 

oh yes, the sound is what wakes me up in the morning. The sleepiness instantly fades when I remember what will happen when I turn that key

I caught myself the other day taking out air and fuel from 80*F cold-start just to make sure the engine is most cranky when it wakes up, I named it the grumpy bitch tune.
I think the general goal for daily drivers is to get a smooth start but for me that is not the case, I want it to kick over like a carb'd engine at -20*F with a huge cam or somethin rofl

 

Interestingly, that's exactly when my car sounds best (see sig for details). Unfortunately it's also the sound of my cylinder walls emptying into the oil pan a few thou at a time.

 

piston wall coating,
makes special cases for us
to do things we love

haiku of the day

 

Reading through this thread, its almost like an older user who was also a young kid then came back to start crap again. His name was Aaron and he also felt the 305 was unrated and he was going to do basic mods to triple its HP.

On the subject of Dyno inaccuracies, this was recently re-enforced when they dyno'd the new C8 Corvette. They said it made 560whp. And a few people I know went nuts raving about how amazing it is. All I could think of was who done screwed up the dyno calibration?

AMS also did a video where they screwed with Dyno calibrations on purpose to fudge numbers.

This spoof video explains how you can screw with the numbers.

 

the people on thirdgen.org dont use horsepower calculators as they are a rookie toy.an h/0 305 is 190 horsepower,an lg4 305 is 150/160 horsepower.
these are not horsepower numbers that were guessed,they are tested and accurate.what you feel is v8 torque and it will make you think you have more
power than you actually do.

 

This is why I only use and recommend the use of dynojet

A dynojet roller is a set mass and cannot be ****ed with

It is a useful tool for comparing all cars, as they are all measured against the acceleration of a known-weight roller. which never changes in mass.

Be wary of any dyno plots not done with dynojet dynometers
All of my tuning and graphs posted are dynojet graphs

 

junior:
why argue about 10-15 horsepower? go run the quarter mile and be prepared to be underwhelmed

 

Here's the thing with trying to equate an engine's HP value and how it'll run in the 1/4 mile.
I'm not trying to bust your chops here Bandit but something I'll throw out there and see what kind of responses it gets.
The ET argument holds true for a given chassis, not engine is that not correct? I can take the same lame 140 HP wheezer (give or take 15 HP) and make it much faster with gearing, converter, tire, etc. Remember that an elapsed time is not about peak horsepower but rather average HP put to the tires. Take the LG4 powered car, put the aforementioned parts in it to keep the RPMs at or near peak and you'll be a helluva lot quicker.
Is that not true? I believe it is.
Case in point, my 86. Just by changing the converter, IIRC, I sliced nearly a half second off my ET. Rather than dropping well below peak torque on the shifts, the revs stayed closer to that sweet spot. On top of that, (only marginally though as the converter wasn't really spec'd), launch RPMs were also further into the meat of torque curve. Further to that, although in a different car altogether, going from a TCI generic 2000 RPM over stock Street Fighter converter (according to TCI), a change to a better engineered YANK converter took another half a second off the original improvement over stock. Nearly a full second all told. Peak engine HP remained the same. Overall average to the tires increased considerably.
So while the LG4 is still a slug, it can be a considerably quicker slug with out engine mods.
Just saying...
As an add on here, take the same chassis, put a more powerful engine in it, and it'll be faster too. Just to head that argument off before it lands.

 

Agreed, I've seen 430hp go 9's at 3800lbs and I've seen 1200rwhp go 12's at 3500lbs





Power, especially the way we tend to look at power as a single peak, is somewhat useless in a general context.

Its why I tend to use power envelopes, or power ranges. My 140hp is your 210hp. Your 250hp is my 160hp.

 

And that's why we shouldn't use ET to calculate HP. ET is so much more sensitive to the first 100ft of the run compared to the last 100ft.

The HP calculators based off Trap Speed vs Weight are much closer to the real power output. A converter/tire/etc... will all help your ET tremendously, and to be fair will have an effect on trap too but nowhere near as great of an effect.

So the Trap speed vs weight is much more consistent data to use.

 

Long story short, yes. My 85 T/A with a wheezy 305 when I got it put down 145 to the tire through a T-5 and the only mod I did was hooker shorty headers. The 700r4 has a short first gear therefore you're probably going off the ol' butt dyno which can be misleading. Cool car man!

 

Any resolution at your end? I've contacted JT ( or whoever runs the show in this regard) through the help forum but have heard nothing in reply.

 

Correct! Although the DynoJet can be manipulated, it is much harder to do so. Also the new software can perform exactly like a Mustang if you have the load absorber (retarder) option. When equipped, the retarders can load the vehicle using all the same factors that you *must* input into the Mustang. You just don't have to input this information for inertia mode on the DynoJet. The drums on our DynoJet weight 2,250 lbs each. It calculates HP based entirely on drum acceleration over time.

DynoJet, or any other chassis dyno, are only for reference against previous (baseline) runs on the same dyno, under the same basic conditions, and for tuning the vehicle under loads that are not safe or legal on the street. Comparing runs between different dyno's is largely a useless internet pissing match. Especially when comparing a DynoJet to a Mustang to a DynoCom, etc.... that's stupid and yields garbage conclusions. What DynoJet has tried to do is largely eliminate the difference between individual serial numbers of THEIR dyno's. So that a DynoJet is a DynoJet and they all read fairly close to the same given the same conditions. By removing the operator inputs the inertia dyno design is much more consistent across all the DynoJet's in operation, while each Mustang is an individual snowflake that reads according the whims of the operator.

GD

 

Dyno time is about getting a job done. Buying time on a Mustang dyno is money much better spent than on a Dynojet.

 

And why exactly do you believe that?

GD

 

Bingo. TRAP & weight tells the HP story. It's all about the trap speed.

 

Exactly. A Top fuel dragster could idle when the light turns green for 10 seconds and run a 13 second pass at 330mph+. And the ET formula would say it probably makes less than 400hp while the Trap Speed formula would tell a story much closer to the truth.

 

Remember that trap speed is an indication of the averaged horsepower. You could, theoretically, take your dyno graph, plot the HP vs RPM, compare that to the actual shift points, launch RPM, etc and arrive at a potential ET. So the top fueler would have zero HP for 10 seconds and 8000 HP (less the clutch timing) for the next 3 seconds and arrive at 400 HP.
See kids? Fun with numbers!