Real Fiero Tech

In other news, the new ignition module is in, and the 12v-USB socket with the little blue LED killed the battery dead while I was underwater... I could have sworn I pulled it out, but I guess I forgot. new battery in, meant I had to take it for a test drive, man did it feel good to drive that old beast again.

ericjon262 wrote: ↑Sun Dec 20, 2020 9:58 am

The Dark Side of Will wrote: ↑Mon Dec 14, 2020 3:02 pm My dad had enough trouble finding a gasoline tach for his Square Body. He actually carried the instrument panel over from his prior truck to install with the Caddy 500 into his current original diesel '90 because he had put the effort into assembling a cluster with full instrumentation.

I wouldn't mind finding a tach cluster for my truck, but it's also no a priority.

I recently watched an episode of "Enginemasters" on motortrend where they swapped the junk '193 heads for a set of L31 Vortec heads with similar intakes and picked up over 100 HP. it got me contemplating doing a very mild heads/cam/intake swap. I really wish this was a factory roller cam block, as I would rather not break in a camshaft.

I have a buddy swapping to aluminum heads, and I might be able to snag his old vortecs cheap.

Intake~$300 new, ~$100 used
cam- ~$180 or so
EBL-Flash ECU mod- $450
TBI to 4bbl intake adapter.~$50
I already have most of the gaskets I need on hand,

The pros:

MORE POWER!
probably better drivability

The cons:

Will probably need a better fuel pump, I don't remember what I put in, but if it's a stock TBI pump, they barely support stock power levels.

money could go towards a diesel or LSx series engine.

the big unknown:

fuel economy change, I feel like this could go up or down.



I think for now, if my buddy lets his vortecs go cheap, I'm going to keep my eyes out for a good deal on an intake, and maybe a used EBL setup, otherwise, I'll leave it as is and keep driving it.

It's totally worth doing.

My first megasquirt install was on my 84 GMC 1/2 ton. The 305 w/tired quadrajet was delivering single-digit MPG, even with 2.73 gears. Mileage was so bad, it factored in with asking my girlfriend(now wife) to move in with me. She lived across town and it was like $10+ round trip when I drove it.

With the TBI, I added headers and performer intake. Tuning with a single-wire O2, i ended up with 15-16mpg on the regular and it would squeal the tires easy.

If I was planning on keeping the truck a Gen 1 smallblock, I think I would be more inclined to drop the coin on the stuff, turns out though, the heads I thought my buddy had, are actually '70 truck heads, and, while they would probably be a step up from the junk TBI heads, I'll pass.

I did have a different thought though, If I were to find a set of LB9 305 heads (TPI) or Aluminum L98 heads, they would bolt on in place of my TBI heads, without the need for a different intake or adapter plate, and be a huge improvement over stock. coupled with a small cam and the EBL board, I could make a bit more power, and economy, with minimal effort and expense on an engine that probably won't be in this truck a whole lot longer...

What about doing the whole TPI? AFAIK those are the best sbc truck intakes, even though they never came on a truck.

Honest Don wrote: ↑Wed Dec 23, 2020 3:04 pm What about doing the whole TPI? AFAIK those are the best sbc truck intakes, even though they never came on a truck.

They aren't bad, but I prefer to minimize the number of new parts thrown at this, if I do the TPI intake, I have to find one, rewire everything, replumb everything, make a new air filter setup, the list goes on and on. if I swap the heads, all I have to do is tune it, and I could even skip the EBL and just have a few chip's burnt, but the EBL is really the way to go.

Honest Don wrote: ↑Wed Dec 23, 2020 3:39 pm https://seattle.craigslist.org/sno/pts/ ... 68603.html

notice the lack of injectors, fuel rails, or any associated wiring? not that I can't do the wiring, but it's just more time, and money when I have a TBI harness/intake/plumbing ect, intact and functioning fine. There's nothing wrong with the tried and true dual plane, and TBI isn't a bad setup, it gets a bad wrap for the shit computer, shit heads, and the fact that they look like a carb, so every hillbilly thinks they can tune it with a screwdriver... if I do anything performance oriented, it will retain the TBI for simplicity. realistically, I'm probably not going to do anything to this truck (other than drive it) until middle/late next year.

ericjon262 wrote: ↑Wed Dec 23, 2020 2:55 pm I did have a different thought though, If I were to find a set of LB9 305 heads (TPI) or Aluminum L98 heads, they would bolt on in place of my TBI heads, without the need for a different intake or adapter plate, and be a huge improvement over stock.

I don't think there's any competition for any 305 heads, but last I heard demand for the L98 aluminum heads was high... resulting in prices similar to aftermarket aluminum heads, but at a lower performance point.

Honest Don wrote: ↑Wed Dec 23, 2020 3:39 pm https://seattle.craigslist.org/sno/pts/ ... 68603.html

Well throw down!

ericjon262 wrote: ↑Wed Dec 23, 2020 3:52 pm

Honest Don wrote: ↑Wed Dec 23, 2020 3:39 pm https://seattle.craigslist.org/sno/pts/ ... 68603.html

notice the lack of injectors, fuel rails, or any associated wiring? not that I can't do the wiring, but it's just more time, and money when I have a TBI harness/intake/plumbing ect, intact and functioning fine. There's nothing wrong with the tried and true dual plane, and TBI isn't a bad setup, it gets a bad wrap for the shit computer, shit heads, and the fact that they look like a carb, so every hillbilly thinks they can tune it with a screwdriver... if I do anything performance oriented, it will retain the TBI for simplicity. realistically, I'm probably not going to do anything to this truck (other than drive it) until middle/late next year.

That was the first one that popped up while searching the area and ones that are more or less complete get posted all the time. I just threw it out there since you're talking head swaps and other involved whatnot.

Don't get me wrong, I have nothing against TBI and I'm actually working up motivation to put one on my FJ60.

The Dark Side of Will wrote: ↑Wed Dec 23, 2020 4:52 pm

Honest Don wrote: ↑Wed Dec 23, 2020 3:39 pm https://seattle.craigslist.org/sno/pts/ ... 68603.html

Well throw down!

I haven't had an sbc anything in years; never say never though.

Honest Don wrote: ↑Thu Dec 24, 2020 12:14 am That was the first one that popped up while searching the area and ones that are more or less complete get posted all the time. I just threw it out there since you're talking head swaps and other involved whatnot.

Don't get me wrong, I have nothing against TBI and I'm actually working up motivation to put one on my FJ60.

I'm sure you already know this, but you can shave the "eyebrows" under the injectors, and it's good for a couple of HP supposedly.

the L98/LB9 stuff looks cool, and makes good torque, I just don't see the overall hassle being worth it. I would be interested in seeing a dyno comparison between a TPI engine with an optimized tune, and the same engine with the stock TBI intake and TB with an optimized tune. I would imagine the TPI intake would perform better down low, but the TBI setup would be better enough everywhere else to be a better overall setup.

I did a quick search, and I was able to find some 305 heads pretty cheap, but I need to research casting numbers to make sure I get the right heads, it would really suck to buy a set and end up with more swirl ports.

I found a few sets of Aluminum L98 heads, they aren't too bad, about $600, but I don't think I'll do that. Looks like the best bang for the buck will be the LB9 305 heads. L98's were factory rated at 245 HP, a gain of about 50 hp over my LO5, I'd bet the LB9 heads on my 350 with a small cam would be good for at least that much, maybe better. I should really just stop thinking about this though, before I start spending money on things I shouldn't.

This isn't what I bought a 3d printer for, but I couldn't resist...







I'll make some revisions, then maybe cast them in aluminum for the finished product.

ericjon262 wrote: ↑Thu Dec 24, 2020 8:29 am I would be interested in seeing a dyno comparison between a TPI engine with an optimized tune, and the same engine with the stock TBI intake and TB with an optimized tune. I would imagine the TPI intake would perform better down low, but the TBI setup would be better enough everywhere else to be a better overall setup.

Somebody at Gearhead EFI of maybe SpeedTalk has done that, I'm sure.
I've read that the TPI intake does indeed give up torque to the TBI intake below 2000 RPM, in favor of punch in the 3500 RPM range. I can confirm that a TPI 400 has brutal mid range torque. My dad has (still has, but the car hasn't moved in years) a TPI 400 in a '70's XJ6 Jaguar with 4L60E and 3.31 gears.

The Dark Side of Will wrote: ↑Thu Dec 24, 2020 4:04 pm Somebody at Gearhead EFI of maybe SpeedTalk has done that, I'm sure.
I've read that the TPI intake does indeed give up torque to the TBI intake below 2000 RPM, in favor of punch in the 3500 RPM range. I can confirm that a TPI 400 has brutal mid range torque. My dad has (still has, but the car hasn't moved in years) a TPI 400 in a '70's XJ6 Jaguar with 4L60E and 3.31 gears.

I realized after I posted that, that Richard Holdener did some tests on an "L98" a while back, I went and looked. This was with a carb, not TBI, but I feel like the illustration is very valid for a TBI setup on a dual plane.



source:

https://www.youtube.com/watch?v=QazvSzZ ... rdHoldener


In other news, I spitballed $40 at a guy on ebay for some L98** heads figuring he would say piss-off, he didn't, so I should have a set of L98 heads here in about 2 weeks... not quite vortecs, but simplify the overall install by letting me retain my stock intake.

**Edit: Iron L98 heads

Damn, dude! Right place, right time!

Soo... that carb conversion, while obviously not being a racing carb, is biased for more top end than the TPI. That being the case, it may be a little large to produce good low end. TBI fuel delivery should be much better at the low end, consequently making more torque than the carb.

ETA: Also... things with a TPI are not quite as simple as old boy says in the video. The TPI is operating using the fourth reflection ~3000 RPM and the third reflection ~4000 RPM... that's why it has so much punch in that RPM range. However, it should operate using the much stronger 2nd reflection ~6000 RPM, assuming someone used a short duration high lift cam and built enough airflow into the system.... which is difficult, even with the Vortec TPI base.

Also note that that guy--and no one else either, really--loads up the engine from 1000 RPM. Where does most of your driving happen? That's why I mentioned above that the TPI intake gives up <2000 RPM torque to the TBI intake... but you can't see any of that from the curves the dude shows. And as noted above, a carb that makes peak power over 5500 is not going to be great below 2000 anyway.

ETA2: The '90's L99, LT1 & LT4 (Gen 2 SBCs) had essentially no runner... well, maybe 4.5" of runner length as the plenum was bolted almost directly to the cylinder heads, with just enough room for injector bosses in between. Since the reflections were active at such high RPM that the engine never saw them, the runners remained non-tuned and just dumped air in when the valve opened. That engine made a FLAT torque curve from idle to 4000 ish RPM then nosed over, but not nearly as hard as a TPI.

The Dark Side of Will wrote: ↑Thu Dec 24, 2020 6:28 pm Damn, dude! Right place, right time!

We'll see when they get here whether it's a good deal or not... I should add that these are the iron variety not aluminum.

The Dark Side of Will wrote: ↑Thu Dec 24, 2020 6:28 pm Soo... that carb conversion, while obviously not being a racing carb, is biased for more top end than the TPI. That being the case, it may be a little large to produce good low end. TBI fuel delivery should be much better at the low end, consequently making more torque than the carb.

Also... things with a TPI are not quite as simple as old boy says in the video. The TPI is operating using the fourth reflection ~3000 RPM and the third reflection ~4000 RPM... that's why it has so much punch in that RPM range. However, it should operate using the much stronger 2nd reflection ~6000 RPM, assuming someone used a short duration high lift cam and built enough airflow into the system.... which is difficult, even with the Vortec TPI base.

Also note that that guy--and no one else either, really--loads up the engine from 1000 RPM. Where does most of your driving happen? That's why I mentioned above that the TPI intake gives up <2000 RPM torque to the TBI intake... but you can't see any of that from the curves the dude shows. And as noted above, a carb that makes peak power over 5500 is not going to be great below 2000 anyway.

Either way, these heads and a small cam will make a radical improvement over what's there now. I'm honestly not a fan of the TPI setup, too many gaskets, too many leak points. they do look cool, but I'll take my TBI that is dirt simple any day of the week.

looks like I'll need to throw down for one of these again...

https://www.dynamicefi.com/EBL_Flash.php

I have a stack of 7730 ECM's in the closet, I'm going to see if he will give me a discount if I send them all to him.

Check out ETA2 above...

There used to be a guy who sold mods to the LT1 intake manifold to adapt it to a distributor style Chevy. Unfortunately his website no longer works.

Red lines are TPIS Miniram(extremely similar to LT1 intake) blue lines are L98 intake, both on a 383 w/AFR 195 heads and a big cam. The short runner still has a very flat torque curve, just much lower, and top end performs much better. as far as not starting the pulls earlier, I understand your point, but at the same time, you rarely are running WOT at 1000 RPM.



https://www.youtube.com/watch?v=B3Je1ML ... rdHoldener

Here's an LT1 dyno. Holdener has a ton of dyno videos.



https://www.youtube.com/watch?v=Z-IJi2x ... rdHoldener

ericjon262 wrote: ↑Thu Dec 24, 2020 8:36 pm Red lines are TPIS Miniram(extremely similar to LT1 intake) blue lines are L98 intake, both on a 383 w/AFR 195 heads and a big cam. The short runner still has a very flat torque curve, just much lower, and top end performs much better.

Not super relevant, but GM's own Big Block Ram Jet intake is pretty similar.

ericjon262 wrote: ↑Thu Dec 24, 2020 8:36 pm as far as not starting the pulls earlier, I understand your point, but at the same time, you rarely are running WOT at 1000 RPM.

My prior Northstar, even for all its faults would accelerate uphill from 1000 RPM in 5th gear... very relevant to daily drivng.

The Dark Side of Will wrote: ↑Thu Dec 24, 2020 10:35 pm Not super relevant, but GM's own Big Block Ram Jet intake is pretty similar.

as is their smallblock Ram Jet intake.

The Dark Side of Will wrote: ↑Thu Dec 24, 2020 10:35 pm My prior Northstar, even for all its faults would accelerate uphill from 1000 RPM in 5th gear... very relevant to daily drivng.

Whole package matters, your N* still has a low geared transmission in a relatively light car, with a fairly powerful engine.

I don't see it as being super useful info, but I also wouldn't mind seeing it available.