Finally got my website up documenting my 3.4L DOHC engine and turbo conversion . Also has some ecm stuff for those of you who are thinking of running this type of setup. The only thing that is still pending is some photos of my car - got it repainted in the fall, but it is off the road now - winter... http://home.cc.umanitoba.ca/~umfreedd
Damn nice setup. Maybe one day my Fiero will get that far.
Edit: Are you using stock pistons? If so, how much boost are you running? If not, where did you get the aftermarket ones, are they forged, and what compression are they?
[This message has been edited by Sacred (edited 01-28-2003).]
Great set-up. I hope we get get details on the turbo install for everyone wanting to do this with a 3.4 DOHC.
What do you want to know? I've listed all the sources for parts on my website (I think), the rest is getting a custom exhaust, plumbing in the oil and coolant lines, then spending hundreds of hours getting the ecm calibration right!
With the location of the turbo and IC, it is nearly impossible to get a pic showing the relation between the two. There is a pipe connecting the turbo discharge to the front end of the IC. The rear end is connected to the intake by a 4" hose.
umm if your running 8psi that intercooler isnt doing you a whole lot. 8psi is the minimum you need to use a intercooler for it to be effective.. if your not ever pushing 10psi there is really no purpose.. the interocooler is to cool down teh air before it enters the intake... this is kinda complicated to understand inless u remember alot about molecules.. hot air molecules move quick and spread apart.. causing friction causing heat. cold air molecules are close together and moving slower.. less friction. Now during compression you cause alot of friction which generates heat. if it stays compressed eventually it will cool to a under room temperature state. At anything lower then 8PSI your intercooler is almost doing nothing because the molecules arent being compressed to the state that they are generating a over excessive amount of heat. by the time the air moves threw the intake tube, threw the throttlebody, into the intake itself and down into the combustion chamber it has reached very close if not the same temperature as if it was pushed threw a intercooler. but since you have it there already might as well keep it..
just to let everyboyd else know that would like to try this setup. you can save yourself a couple of bucks.
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12:27 AM
AnimalGT Member
Posts: 1118 From: Chicago, IL Registered: Jul 2001
Looking great, Im alittle jealous. There are now 3 "completed"č Turbo 3.4 DOHC Fieros. I myself am doing a 3.4 DOHC Supercharged if you haven't seen it already. I just love the prospect of a boosted multivalve engine, especially greater then 4 cyls. The one thing I'm worried about is compression, the LQ1 has anywhere from 9.2-9.7:1. Mine was 9.7:1. I will be shelling out some $$$ for custom Forged pistons. This engine will be well tuned with a 1227727 (89 Grand Prix computer with a modified turbo code) Just going over your webpage, it looks like you have set up a great ECM boost resourse and will save ME A LOT of time. I really appreciate this free sharing of info!
č no car is ever COMPLETED
------------------
"How do I get one of those Smileys that rolls back and forth accross the screen?" -Archie
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01:34 AM
DKOV Member
Posts: 1564 From: Portland, OR, USA Registered: Mar 2001
Looks great although I have one question... Oil Return Line?
That thing is nearly horizontal. I've heard that the oil return line needs to be as close to verticle as possible and not more than 45 degrees at any point. Reason being, the oil gets pretty agitated as it moves through the Turbo and come out, well... FOAM. Because of this, you need the biggest and most verticle return route to the pan.
I don't know if this is true or not but I know of a 3.4L DOHC motor running a turbo that routed the turbo in the exact same manner. The oil return finally failed to drain enough of that FOAM and it all backed up into the turbo and punched through the bearing seals, into the intake and toated the motor.
Since then, they've moved the Turbo up and installed a verticle tube and no issues since.
I've been racking my brain to get my Turbo to install vertically for that reason.
How many miles is on your motor since the Turbo was installed in that place? How many miles under boost... Sustained Boost?
If it's working out for you, I may just change my mind
umm if your running 8psi that intercooler isnt doing you a whole lot... At anything lower then 8PSI your intercooler is almost doing nothing because the molecules arent being compressed to the state that they are generating a over excessive amount of heat. by the time the air moves threw the intake tube, threw the throttlebody, into the intake itself and down into the combustion chamber it has reached very close if not the same temperature as if it was pushed threw a intercooler. but since you have it there already might as well keep it..
just to let everyboyd else know that would like to try this setup. you can save yourself a couple of bucks.
I've actually measured the temperature of the air post turbo and post intercooler. At 8psi, the temp post turbo is 63 deg C, and post IC is 31 deg C. That was on a day when the ambient was about 18 deg C. I would not omit the IC since you can usually buy these on ebay for less than $50! At the airflow rates that are present under 8psi boost, the intake charge is not going to get heated that much by the intake, therefore it is my opinion that an IC can only be a good thing.
Looks great although I have one question... Oil Return Line?
That thing is nearly horizontal.
How many miles is on your motor since the Turbo was installed in that place? How many miles under boost... Sustained Boost?
I know what you mean. I think that is the biggest concern about this setup. I haven't had any troubles so far, other than occasionally some smoke on startup - from oil leaking into the exhaust, I guess. The problem with low lying turbos is smoking at startup or idle as opposed to smoking under boost (usually). That is from oil seeping around the piston ring and getting into the exhaust. This winter I installed a stagger gap piston ring from Turbonetics - they suggest that these be used when you have a low lying turbo. We'll see if it works. The other possible explanation for smoking is that the oil supply is overwhelming the bearings and seals. You have to remember is that the turbo requires very little oil - I've read of some guys installing restrictors in the supply line - like .060 opening. Personally, that makes me nervous. I should really measure the oil flow rate I guess. Two other solutions: use a dedicated sump for the turbo, or use a "oilless" turbo like an Aerocharger (which Corky Bell seems to prefer).
You'll notice that the diameter of the return line is quite large - its 3/4" hydraulic hose. I'm hoping that its size will offset the low drain angle. I've driven this thing pretty hard - regularly autocross it, but it's only been about a year since the turbo install - can't recall the mileage right now, but boost is like a drug! That car is so fast, seems like I'm always on boost.
do you know what the a/r ratios of your turbo are? i haven't gotten around to finding the proper a/r ratios for the intake and exhuast housing but this would at least be some #'s to start with. TIA, later.
------------------ Eric '87 GT 5-speed Gold/Tan NOW with a 4.10 4-speed 3.4 TDC + other goodies coming summer of '03
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09:26 AM
DKOV Member
Posts: 1564 From: Portland, OR, USA Registered: Mar 2001
Originally posted by 3400Fiero: I haven't had any troubles so far, other than occasionally some smoke on startup - from oil leaking into the exhaust, I guess.
Have you checked the inlet side of the equasion for oil pass through? On my Lotus Esprit Turbo, I had the original Turbo loose a little Blow By into the exhaust and ultimately found oil in the intake crossover. Not a good thing. Talk about smoke in the exhaust
Your install looks a LOT easier than what I'm doing right now, but I guess I'm still afraid of the "low rider" turbo position.
Fierobsessed - get 3.4 pushrod pistons, they'll give 9.1:1 compression, then have them shaved .010"-.020" and you'll have 8.8-8.9:1. eyebrows may need to be cut into the pistons to clear the valve, i know i'm gonna have them cut in before i use them in my motor. my local machine shop only wants $18 a slug to mahcine them, so a set of forged 3.4 pushrod pistons is probably ~$300 then $120 to machine them, custom pistons are only $650 so you save a few dollars.
------------------ Eric '87 GT 5-speed Gold/Tan NOW with a 4.10 4-speed 3.1 TDC + other goodies coming summer of '03 -2.8 aluminum head crank, 6" SBC rods, 3.4 psuhrod pistons (8.8:1), T3/T4, custom built headers and Y-pipe, 36#/hr injectors.....will be the 1st destroked TDC, 4th completed turbo
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12:54 PM
Fierobsessed Member
Posts: 4782 From: Las Vegas, NV Registered: Dec 2001
Keep in mind I have 96 heads, Very different from the 91-95's The problem with shaving the piston down to lower compression is that it adversly effects the quench area. The amount of detonation you would loose by lowering the compression would come back when the quench area is lost, the 96 heads have a good amount of quench area when compared to the 91-95 heads. I was thinking of just flat out going with the 3.4 PR forged pistons but only decided against it since the forged 3.4 pistons are specifically designed to raise compression. Stock 3.4 pistons would put me around 8.2-8.5:1 or somewhere about that figure. I will look into what can be done to the forged pistons in order to perhaps lower compression. I'd like to stay away from taking out the quench area if at all possible.
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08:25 PM
coinball Member
Posts: 1526 From: Raleigh, NC, USA Registered: Apr 2002
what exactly is different in the 96+ heads other than the ports, i thought the valves and combustion chambers were all the same? now what exactly is the quench area, i "used" to know what that was i can't think of what it is right now, its been a long day.....anyway, please enlighten me. i keep thinking the quench area has something to do with the compressed air/fuel getting shoved into the center of the combustion chamber, i dunno, anyway, u could get around shaving the pistons by destroking it and going with 6" rods , this lowers the top of the pistons .020" (difference in the rod+stroke length vs stock configuration)....will this affect the quench area also? i'm guessing yes.....
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10:01 PM
Jan 30th, 2003
DreXteR Member
Posts: 1763 From: Orlando, FL Registered: Aug 2000
It will definatly effect the quench area the same way. Quench area is where the piston nearly touches the heads surface, in the picture you can see the difference in the combustion chamber The (96-97) clover shape has more quench area then the (91-95) non clover chamber. The exhaust valves on the 96-97 heads are tuliped, meaning they are indented in the center of the valve. Before you consider using a 2.8 crank in a LQ1, verify that the 2.8 crank has rolled fillets. Without them the crank may be too weak for such a high powered application, unless you somehow come across a forged crank. The LQ1 crank is also specially balanced for "high RPM balance".
[This message has been edited by Fierobsessed (edited 01-30-2003).]
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07:06 PM
coinball Member
Posts: 1526 From: Raleigh, NC, USA Registered: Apr 2002
ok, so how do you change the compression without changing the quench area? or is it not possible, do u have to compromise between the compression you want and the quench area? i thought gmpartsdirect offered a rolled fillet aluminum head crank but they only have the iron head crank with rolled fillets. is they anyway to use an MSD external magnetic crank trigger with the stock ignition so that i could use the 2.8 iron head crank? i guess i could make that work but then i need to get a MSd DIS-4 ignition since the TDC ECU wouldn't have a clue what to do without a crank trigger....even if i went without the rolled fillet crank i should be fine with no detonation, hell if i have detonation bad enough to break the crank, the pistons i'm gonna use would be long gone before the crank gave way. with an intercooler and a 7th injector i can keep on top of 12-14 psi without any issues. speaking of 7th injectors, do i still use a pulse type injector or a constant flow injector like a cold start injector? i'll be controlling the timing and fuel issues with my dynotuner box, so i guess i should drop Ed an email about it....
------------------ Eric '87 GT 5-speed Gold/Tan NOW with a 4.10 4-speed 3.1 TDC + other goodies coming summer of '03 -2.8 aluminum head crank, 6" SBC rods, 3.4 psuhrod pistons (8.8:1), T3/T4, custom built headers and Y-pipe, 36#/hr injectors.....will be the 1st destroked TDC, 4th completed turbo
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07:20 PM
Fierobsessed Member
Posts: 4782 From: Las Vegas, NV Registered: Dec 2001
Some of the earlier second generation aluminum headed engines were 2.8's. They also had DIS ignition and therefore have the crank trigger, The external aftermarket crank trigger is a great solution to that problem. But I am still not sure if any 2.8 cranks were available with rolled fillets. Truthfully they arn't 100% necessary, just would be really nice to have for a high performance, REALLY high revving engine. About changing compression without changing quench area, simple answer: Dished pistons. The second generation engines all had low volume cylender heads and dished pistons, the quench area was good because the flat ring around the top of the piston still came up close to the head maximizing quench area. Assuming you have flat top pistons that come up level to the top of the combustion chambers, the area highlighted in red show your quench area, as long as the surface of the piston comes close to meeting this part of the head, you have maximized your quench, If your piston stops short of the bore, then none of it almost meets the head, meaning no quench area at all. Now, the area between the red, you can have the piston be dished as far away as you want without effecting quench, providing your piston top is still thick enough. Its the dishing like that, that will change your compression without loosing quench. Take a good look at the web page that 3400Fiero Posted in the top post. He has re worked a special code for his own engine to maximize performance, using a production GM computer. This is by far the cheepest way to do it right. No need for a seventh injector setup. I once installed a turbo on a ZC (DOHC) 86 CRX. We used a computer system that put 2 more injectors into the charge pipe and compensated for the need for additional fuel on boost. Worked pretty good. The injectors were standard style pulse type injectors, varying with boost levels. I don't see any way that you could get a fixed volume injector to work.
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10:54 PM
Jan 31st, 2003
coinball Member
Posts: 1526 From: Raleigh, NC, USA Registered: Apr 2002
what about dished pistons from the second gen TDC, what kind of compression would i be looking at? remember they'd be .020" lower becasue of the rod/stroke combination, hopefully around 8.5:1, this .020" would affect the quench area, but i guess i could have the head decked .020" to make up for it, but then i kick the compression back up. what about milling a set of stock TDC pistons (1st gen), like connecting all the eyebrows in the piston top to make a dish? i'm not too sure about milling hyperuetectic pistons though...
------------------ Eric '87 GT 5-speed Gold/Tan NOW with a 4.10 4-speed 3.1 TDC + other goodies coming summer of '03 -2.8 aluminum head crank, 6" SBC rods, 3.4 psuhrod pistons (8.8:1), T3/T4, custom built headers and Y-pipe, 36#/hr injectors.....will be the 1st destroked TDC, 4th completed turbo
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09:26 AM
DreXteR Member
Posts: 1763 From: Orlando, FL Registered: Aug 2000
Fierobessed hit in the nail. If you are going to boost is better if you go with forged pistons. JE and others manufacturers do custom pistons, you can make a set with lower compression and use the DOHC crank. Less problems to deal with, the custom pistons will solve your problem.
I just had a chat with a friend of mine who is old school - knows a bit about quench. He figures that quench area is important with the "domed" pistons that these engines run. If you are going to lower compression by removing the dome or by making a "dished" piston (which is what I am hoping to do - someday...) then quench is not really an issue. FWIW. Sounds reasonable to me.
I personally think that if you setup the engine correctly, and take all the necessary steps to avoid detonation, quench is not as great a concern. An example of what I mean is in Corky Bell's book, Maximum Boost. In there he demonstrates how to do a custom turbo setup on a Acura NSX that has 11.0:1 CR stock. He didn't change the engine at all, but added two turbos WITH intercooling, and is only running 6 psi (he got about 395 hp IIRC)! My phiolsophy with my setup is that I want to know what the stock engine can hold up to if every step is taken to protect it. As a result I haven't made any mods to the engine as of yet. I only recently upgraded the spark plug wires and decreased the spark plug gap (I am already using colder plugs) because I was getting misfiring under heavy load (read boost).
Just my .02
Fierobsessed: thx for posting the pics of the cylinder heads! ------------------ 1988 Fiero Turbocharged, Intercooled 3.4L DOHC http://home.cc.umanitoba.ca/~umfreedd
[This message has been edited by 3400Fiero (edited 01-31-2003).]
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11:14 AM
coinball Member
Posts: 1526 From: Raleigh, NC, USA Registered: Apr 2002
drexter - the whole purpose of the 2.8 crank is to destroke it so i can rev to ~8500 with the appropriate valvetrain.....plus the 6" rods will give a longer dwell at top dead center for more power...
drexter - the whole purpose of the 2.8 crank is to destroke it so i can rev to ~8500 with the appropriate valvetrain.....plus the 6" rods will give a longer dwell at top dead center for more power...
What mods for the valvetrain do you have planned? I would be careful reving that high unless you are planning to increase valve spring rate and convert to a chain driven valvetrain. I personally think there is way too much flex with the valve timing belt to have reliable valve timing at that high of an rpm, especially if you start increasing the stiffness of the valve springs. I've had my engine up to ~7300 rpm, and it doesn't sound pretty...
i haven't cross referenced yet but i'm planning on using SBC springs, or whatever springs match the stock TDC springs the closest. i don't think the t-belt will be an issue, ferrari uses belts in their DOHC motors and they rev to 8 without any problems, i'll have to find out whether or not the t-belt makes it to 8500....
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01:48 PM
Sacred Member
Posts: 180 From: Midlothian, VA Registered: Mar 2002
I thought I read some where that the quad4's springs and 3.4L TDC's springs had the same gm part number. If this is true then couldn't you use quad4 aftermarket springs?
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03:09 PM
PFF
System Bot
Fierobsessed Member
Posts: 4782 From: Las Vegas, NV Registered: Dec 2001
perhaps the Northstars springs might do the trick too, but I dont know much about them. According to www.60degreev6.com the Quad 4 lifters should fit the 3.4 DOHC engine fine, and they are shallower, perhaps even lighter.
I have to agree, good high Rod to Stroke ratios are VERY effective for eliminating detonation, Quench has a nice effect and spark plug location is another (its in the center; the best place possible) The type of metal used for the heads also helps, aluminum being better then cast iron for some reason.
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06:56 PM
Feb 1st, 2003
coinball Member
Posts: 1526 From: Raleigh, NC, USA Registered: Apr 2002
as soon as i finish paying for my wiring harness, finish my 11.25" brake swap, and finish my suspension crap (roughly early april), then i will start to buy all the internal parts....i should have the short block completely assembled by the end of may, and hopefully have the whole car done by mid late june....only time will tell, anyway, keep an eye out for my progress....
------------------ Eric '87 GT 5-speed Gold/Tan NOW with a 4.10 4-speed 3.1 TDC + other goodies coming summer of '03 -2.8 aluminum head crank, 6" SBC rods, 3.4 psuhrod pistons (8.8:1), T3/T4, custom built headers and Y-pipe, 36#/hr injectors.....will be the 1st destroked TDC, 4th completed turbo
That's my TGP code disassembly on your website. I put it on the DIY-EFI site a couple of years ago. It looks like someone added more to it and cleaned it up a bit. Nice job.
That's my TGP code disassembly on your website. I put it on the DIY-EFI site a couple of years ago. It looks like someone added more to it and cleaned it up a bit. Nice job.
Yes, TK, good eye!! Thanks for figuring out the ALDL stream. That gave me a good place to start. Unfortunately I had to do ALOT of work to get it in the shape its in now, and I'm still not completely done... I've also posted this updated/revamped hack to the diy site, FWIW.
I am curious, what are the other two images of the 8F code? I guess that AUAF is Federal emmissions, and one of the other two are California emmissions, so whats the third one?
Oh I found some stuff in your Dissassembly, I kinda like it!
8D98 00 MANUAL VEHICLE OPTION FLAG (01 = MANUAL) hey, it already has all the histerics for a shift light, so why not?
8F1E C9 MAP 157 KPA MAP BOOST LIMIT CUTOFF Lets see now, increase this value...
Another interesting thing, in the program, as boost increases past 160KPA (around 9 PSI) of boost, the injectors dutycycle maxes out. Fortunatly the boost is limited to 160KPA.
Looks like its going to be just tweaks to the fuel and spark tables, as well as some rev limiter mods, and get rid of that pesky speed limiter. can't wait!
[This message has been edited by Fierobsessed (edited 02-02-2003).]
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01:20 AM
bushroot Member
Posts: 496 From: Grand Rapids, MI, USA Registered: Jan 2003
I am curious, what are the other two images of the 8F code? I guess that AUAF is Federal emmissions, and one of the other two are California emmissions, so whats the third one?
I know of 3 TGP .bin files: AUAF, AUFR, AZRC. It looks to me like AUAF was the earliest (released 1989), AZRC is the latest (released 1991) and AUFR is somewhere in between. Don't know about emissions, though. I think AZRC is also Federal...
quote
Oh I found some stuff in your Dissassembly, I kinda like it!
8D98 00 MANUAL VEHICLE OPTION FLAG (01 = MANUAL) hey, it already has all the histerics for a shift light, so why not?
That flag is not for the shift lite; it is for the throttle follower. When that flag is selected, the IAC steps specified in 8D99 are added to the total throttle follower steps. Unfortunately the shift lite algorithm is completely missing in $8F, so the cals are never called, and the lite won't work.
quote
Another interesting thing, in the program, as boost increases past 160KPA (around 9 PSI) of boost, the injectors dutycycle maxes out. Fortunatly the boost is limited to 160KPA.
Are you referring to the BPW mutiplier vs 2 bar map index table at 8EE4? That is mearly a multiplier (0-2) and is not reflective of what your duty cycle will actually be. Duty cycle will depend on what injectors you choose to use.
quote
Looks like its going to be just tweaks to the fuel and spark tables, as well as some rev limiter mods, and get rid of that pesky speed limiter. can't wait!
I wish it were that easy. It took me about 50 chips just to get the thing started and idling nicely, and about another 100-150 to get it where it is now. Although I'm a bit of a perfectionist - I like driveability - I wouldn't expect it to work without alot of work. Although it is quite easy to tune a car to go fast, it is quite another thing to also make it driveable with decent gas mileage. I'll be here to help you when the time comes - if you desire.
Originally posted by Fierobsessed: Looks like its going to be just tweaks to the fuel and spark tables, as well as some rev limiter mods, and get rid of that pesky speed limiter. can't wait![/COLOR][/SIZE]
I seen 3400s responce as well but I have a question...
My 1991 GTP, and consequently now, my Fiero has the 3.4L TDC motor on board and it does NOT have a speed limiter.
I am told that the early release, as in the first 60 motors or so, that were released with the Getrag 284 transmission came that way. All the motors that followed added the Speed Limiter and then the year after, added the MAF sensor.
I don't know if this is true but I have had my car to 156 and with the limiters I've been told it's only 121 mph
your right, the 89 GTP didnt have a speed limiter. it maxes out at 255, witch I wouldn't worry about going that fast yet I know Ill be burning insane amounts of chips, because I probably burnt 15-20 and have gotten practically nowhere, I couldnt get the car to Idle for nothing, surge surge surge die. I quickly got the hint that it wouldn't be so simple. I dont know why I thaught that that table represented the duty cycle based on boost, thats what happens when you stay up way past bed time. I know that duty cycle is based on MANY different factors. Are you running lean cruise (hiway mode) on your car? How did you go about tuning it? wideband OČ sensor? Dyno? Scan tool and BLM?
[This message has been edited by Fierobsessed (edited 02-02-2003).]
. Also has some ecm stuff for those of you who are thinking of running this type of setup. The only thing that is still pending is some photos of my car - got it repainted in the fall, but it is off the road now - winter... 
Although I'm a bit of a perfectionist - I like driveability - I wouldn't expect it to work without alot of work. Although it is quite easy to tune a car to go fast, it is quite another thing to also make it driveable with decent gas mileage. I'll be here to help you when the time comes - if you desire.
