The "4.9 liter turbocharger, stage 1" thread.

[N0DIH]

Remember too, as we discussed a while back, you want to go with a too big turbo on a 4.9L.

You have a base compression of 9.5:1 with a small cam. The cyl pressure is high enough already. A properly sized turbo will do 1 of things, blow head gaskets, ping uncontrollably in boost (even unheard pinging is deadly), melt pistons due to lean mixture (someone makes a fuel pressure regulator that ups pressure 1:1 ratio with boost, I think I was saying earlier that you needed 1lb more injector per lb of boost, I meant 1 psi more fuel pressure to 1 lbs more boost, sorry! Else the boost will be pushing back the fuel pressure, so every PSI higher the boost is the fuel pressure is that many psi LOWER, remember, the fuel pressure is maintained based on atmospheric pressure, not intake pressure). The engine will start falling off in cyl pressure around 3500-4000 with that cam. With a larger turbo you want boost coming on strong by 2500 to 3000 rpm to flatten out that torque/hp curve.

Check with the supercharger companies. Magazines show them all the time too.

So calculate how much fuel the stock 18lb injectors can support and see how much you think you will get out the 4.9L boosted and make sure the 18lbers will support that much power. Plan for a 12.3 or so fuel mixture, not 14.7. Turbos need extra fuel to keep from melting pistons. Been there done that, I have a reasonably designed 301 Turbo that DID get enough fuel and it will leaned out enough that I melted #7 @ 100+ mph......

So your TBI fuel will have to be boost referenced for sure, the stock fuel not really, as the TBI will support more than enough. But TBI's need around 10 psi, the PFI needs 45. Any thoughts on managing the fuel pressure? I don't know how much pressure is in the return rail, if it is higher than the TBI's outlet return rail, it will not be able to manage it's pressure well, it at all.

My 301 Turbo had a Garrett TBO305 with a .82 A/R. Which is ok for, but there are so many other restrictions the 301 never could live up to its potential. Once I get the $$, I don't see why a 350-400 hp 301 with a carb draw through system would not be EASY. As it was with as bad as it was with 7.5 psi I was putting 290 HP to the ground. No intercooler, just a M4ME Q-Jet, special HEI and a pathetic set of heads and intake....

http://www.turbomaster.info/eng/

http://64.233.161.104/search?q=cache...ri%20target=nw

[illumina]

Hey Tom, I have an interesting idea...

I was talking to someone who has several key items I may need to get this turbo project under gas. These items include the following:

Allante 4.5 liter intake manifold, both upper and lower,
Allante steel rocker arm supports,
Allante fuel rail,
Allante throttle body (TB).

All of this can be had for $250.00!!! (Another $20.00 for shipping.)

Basically what I was thinking was that the Allante intake manifold is much more open and could possibly support 8 more fuel injectors in addition to the 8 already on there for a total of 16 injectors: 8 for the stock system; 8 for the auxiliary system. I can fine-tune the auxiliary fuel system for boost and keep it quiet under normal driving so as not to disturb the stock fuel system while under closed-loop/part throttle operation. With all 16 injectors, it should be safer to tune this thing out.

The steel rocker supports are just a bonus for roller-rockers and a stronger valvetrain assembly.

The only thing I'm worried about is the throttle posistion sensor (TPS). I believe it is still the round connector type that is standard on the 4.9 liter, but I'll have to match sensors or part numbers to be sure.

Also with this setup, it may be easier to run a water injection aftercooler or just a plain intercooler too.

Let me know what you think.

[Stoneage_Caddy]

also remeber how much easier it will be to plumb that allante manifold to the turbo than the stock stuff

[CallMeCrazy]

Anyone have any thoughts on my application? Keep in mind that it is hopefully going on a 2.3 4cyl with 7.8:1 compression.

BTW- I've done some calculations on the GM3 compressor side and it works out to be a 53 trim. I haven't gotten to the exhaust side because the center section is fused to the exhaust side via rust :rolleyes2

Once I get the center cartridge seperated from the exhaust side, I'll be able to measure the turbines trim and the exhaust sides A/R.

Just from eyeball comparing, the turbine appears to be no bigger than my aiResearch .60/.63, BUT, that is only looking at the inner portion of the turbine. The inside could possibly tell a compeletely different tale. From looks though, it doesn't appear to be any larger than the turbine that I am using currently.

[Stoneage_Caddy]

crazy are you talking quad 4s ?

if thats the case stuff for you is readily avaible thru GM as a blower kit ....

[CallMeCrazy]

No, my motor is too small for a blower kit, it's a 4 cyl I'm planning on a late spool but not much later than what I am running currently. There are guys running the same .60/.63 and edging 11's in the 1320

[Stoneage_Caddy]

the quad 4 was a 2.3l 4 cyl .....came in everything from oldsmolbiles to chevy cavaliers and a few berattas ...gm relased the blower kit for it in late '00 if memeory serves

[N0DIH]

Originally Posted by illumina

Allante 4.5 liter intake manifold, both upper and lower,
Allante steel rocker arm supports,
Allante fuel rail,
Allante throttle body (TB).

All of this can be had for $250.00!!! (Another $20.00 for shipping.).

Awesome!! Hopefully it isn't too tuned, turbos aren't the fondest of intake tuning for NA engines, it can make them peaky. But I don't think it should be a problem at all.

Originally Posted by illumina

Basically what I was thinking was that the Allante intake manifold is much more open and could possibly support 8 more fuel injectors in addition to the 8 already on there for a total of 16 injectors: 8 for the stock system; 8 for the auxiliary system. I can fine-tune the auxiliary fuel system for boost and keep it quiet under normal driving so as not to disturb the stock fuel system while under closed-loop/part throttle operation. With all 16 injectors, it should be safer to tune this thing out.
Let me know what you think.

8 injectors addtional seems pretty excessive, you won't need that much. Not to mention the plumbing of them. But then again, they require the same pressure as the rest. A potential issue is with all 16 injectors dumping fuel it very well might overcome the capacity of the fuel pump. A 255 liter/hr pump might be needed to keep up with the demand. Again, an issue is if the injectors are boost side, you will need boost pressure+fuel pressure to keep the same fuel pressure relative to the injectors. A special boost referenced regulator is required.

I like the ease of the TBI unit, and how easy it would be to trigger it (2 drivers instead of 8). I will look into having 8 injectors to drive and see what I can come up with. I can't imagine needing large injectors, smaller here might be a good thing. Consider at WOT and 14.7 psi boost (1 bar) you, in theory, would need 2x the fuel delivered over stock. That is assuming that you have 100% VE at stock and used all of what you had, and boosted you are equally efficient, 200% VE by then. But in reality a boosted engine will see more like 120-130% VE (Volumetric Efficiency). And stock engines are typically more like 80-85% VE at best. And that is not always at all RPM's. It might be 50% VE at 1000-2000 rpm, 75% by the time you hit 2500 rpm, etc... Maybe peak at 85% for a short time at 5000 rpm. MAYBE. If the planets line up.... And how to calculate?? Dyno time.... BSFC, power and rpm make up some of it.

So I would anticipate if all was running well, you would need upwards of 45% more fuel than stock. So like 30 lb injectors would handle it all with only the stock 8 locations. And then tweak the code in the ECM (the BLM value and the fuel cells) to supply it when boosted (>1 bar on the MAP)

[CallMeCrazy]

Originally Posted by Stoneage_Caddy

the quad 4 was a 2.3l 4 cyl .....came in everything from oldsmolbiles to chevy cavaliers and a few berattas ...gm relased the blower kit for it in late '00 if memeory serves

Yeah I know about those motors but this is entirely different. It actually started as a 2.2 12V but with overboring .50, it ends up being a 2.3 which is why you might be confused on the actual motor. Mine is the F2T found in the 88-92 Mazda MX6 Turbo. The pistons are still the stock 7.8:1 c/r, but after all is said and done with the block and head, my compression will be roughly 8.5:1

[illumina]

Originally Posted by N0DIH

8 injectors addtional seems pretty excessive, you won't need that much. Not to mention the plumbing of them. But then again, they require the same pressure as the rest. A potential issue is with all 16 injectors dumping fuel it very well might overcome the capacity of the fuel pump. A 255 liter/hr pump might be needed to keep up with the demand. Again, an issue is if the injectors are boost side, you will need boost pressure+fuel pressure to keep the same fuel pressure relative to the injectors. A special boost referenced regulator is required.

The thing is, I've always planned on using a secondary fuel pump for this project anyways. It will be an either an in-line deal that will be controlled directly with the Megasquirt (MS) system or seperate from the stock fuel system all together just using the MS system. The stock fuel system will therefore be untouched in the latter matter. I forgot too, the MS system reads 2 bars...Good news for the project.

The only thing with using the TBI system...Well, I could still use that system I guess...

By the way, I would love to just hack the stock ECM and forget about the expense of a MS system and all, but as of now, the only person willing to help with that needs my car in-garage (yeah, like that's going to happen) somewhere far from my state. I have priced an EPROM reader/burner and EPROM programmer for this but it will cost near $1000.00 extra than I have right now.

[85coupeJase]

use of 16 injectors is to much, especially piggyback. the reason people may say to stay away from piggyback systems is that with only one injector per cyl.. if it fails no problem. but if there are two and one fails then you have an extremely lean situation.
"MegaSquirt has just two injector drivers (that can handle up to ten injectors each), "
if you wanted to be creative you could multiport inject off one driver and tbi inject extra for boost off the other. haha fun.
all im saying is 16 injectors = problems arising in my mind.
take care, sounds really cool

[N0DIH]

Here is some additional reading: http://www.junkyardturbos.com/101_1.asp

http://www.junkyardturbos.com/projects.asp

http://www.junkyardturbos.com/forum.html

He runs 12.80's with 3 psi boost on a LS1 in a Z28. Not bad!!

[illumina]

I went with the GM3 for two reasons:

1.) Cheap.

2.) The Fiero guys used the similar GM4 on theirs and ran 12.27 on 6-7 psi...They modded their 4.9 liter to get the 12 second quarter mile, but even before then the used engine without mods and 3.13:1 gears (modded 440T4 tranny) with a posi was running low 13's.

Tom, great links dude They are doing the same thing I am doing: a budget turbocharger project. I am likely going to join their forum for extra input.

[JunkyardTurbos]

Originally Posted by N0DIH

Here is some additional reading: http://www.junkyardturbos.com/101_1.asp

http://www.junkyardturbos.com/projects.asp

http://www.junkyardturbos.com/forum.html

He runs 12.80's with 3 psi boost on a LS1 in a Z28. Not bad!!

I actually ran the 12.8 before the turbo. I had a few mods done at that point. At 3 psi, I'm hoping for low 12's. I'm going to jump to 6 or 7 psi with alky injection. The kit cost me about $850 using a junkyard Holset turbo.

I really want to do a Caddy project. There is a guy on my site doing a Fleetwood turbo kit. I was thinking of a Coupe DeVille sleeper project. Any other suggestions on what might make a nice turbo sleeper?

[N0DIH]

Almost like the person who is on the Junkyard Turbo site is lurking here as well....

Hmmm......