depending on my tax return/graduation money, i might be shooting for custom cams too which in that casei'd be shooting for low 13's to high 12's. With lightweight lifters and blue-printed/rebuilt bottom end i might get into the mid 12's but thats a long ways off. Besides, if I went that far, I would have a turbo too. Thats for when Im rich or when I win the lottery. I think that this motor has the potential for 450 horsepower turboed if built right.
So who wants to make a set of headers? I know that there was a webpage somewhere where a guy made a set... Dave? he was from Michigan... its not you Aaron. Also, does anyone know of a place where I can get 96-97 intakes?
------------------ REMEMBER: If you cant win the race you loose the argument!! 3.4 DOHC Motor Swap-14.7 in the 1/4 mile with no hook-up, crumby exhaust and automatic chip. Better exhaust, chip, cam retarding, and driver to come... I'm feeling lucky! www.geocities.com/j_depies
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01:47 AM
crzyone Member
Posts: 3571 From: Alberta, Canada Registered: Dec 2000
Fieromadman, 280 HP out of a DOHC has been done. One thing AaronZ34 will agree with me on, is that you could use a good equal length, tuned header in addition to tinkering with your cams and possibly, a short runner intake (96+ or build one even more radical).
Blue 1987 GT Getrag 5 speed, 1" lowering springs, 225 50R16 rims and tires, Fiero Store 9 3/4" HD clutch (Soon to be 3.4L DOHC powered!) Silver 1986 2m4 THM 125c automatic Black 1985 2m4 SE Isuzu 5 speed (no paperwork)
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03:38 AM
fieromadman Member
Posts: 2217 From: Oconomowoc WI, USA Registered: Jan 2003
I know that it has been done, and rather easily, but what Im trying to create is a whole 'nother beast. That website with the short runner project shows that there is a decrease in low end power, and your waiting forever for the powerband to come around. What I would like to be able to do is to use the stock powerband, preserving the low end, but then adding on to the mid range and top end. IMHO, this engine doesnt breathe well enough at high end, making the DOHC's less usefull. However since its a daily driver, I would like to retain some low end power. So I feel that equal lenth headers, a modified intake manifold (either ported out 96-97 intakes or a custom earlier intake (discussed later)), cam retard, 3 angle valve job, shaved heads, mandrel bent exhaust (thinking about routing it in the stock fiero way with a custom crossover in 3 inch diameter to a 3 inch bolt in cat (so I can pass emissions, but a resonator piece made to the same dimensions that is bolt in-able) then 3 inch back to the Y-piece then spliting off to 2.5 inch with 2.5 inch resonator tips (no muffler), then a CAI is the best way to get power out of this motor for the least ammount. If need be depending on dyno results, I may end up putting in light weight lifters and getting an chip burned so I can rev to 7500 easily to make the most of the power-band. In the future, custom cams, and a full blueprinted bottom end and another set of heads without them being shaved (I have 2 sets), and then a turbo kit with a conservative 7 psi. I think that should be good for around 450 horsepower, granted the other mods. If I end up doing a custom earlier intake it will be using 3" tubing to connect a LS1 thorttle body to the upper part of the intake chopped off to eliminate the the shitty T-body transfer and open up the breathing. Now, I have a few questions on that, since there is a built in IAC will the connector for the LS1 t-body work with the 3.4 DOHC computer? Also, what about the Coolent passage that goes through the intake area? Is there a way to bypass it easily?
------------------ REMEMBER: If you cant win the race you loose the argument!! 3.4 DOHC Motor Swap-14.7 in the 1/4 mile with no hook-up, crumby exhaust and automatic chip. Better exhaust, chip, cam retarding, and driver to come... I'm feeling lucky! www.geocities.com/j_depies
[This message has been edited by fieromadman (edited 02-10-2005).]
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02:58 PM
AaronZ34 Member
Posts: 2322 From: Colorado Springs, CO Registered: Oct 2004
It can be easily bypassed. Back when I was building my independent throttle body setup (I am finishing it, dynoing it, and selling it for a whipple supercharger), I had to negotiate these. There is one coolant outlet form each head, and they are on the driver's side of the engine. They combine, and exit. Once combined, there is the heater inlet, and a area for some coolant to travel up through the TB. After going around the TB, it runs around the engine in a small tube, and back into the mainstream cooling pipe right before the water pump. To bypass this with a new intake, you have to tap the hole where the UIM meets the LIM. There is a O-ring there that prevents leaking, but other than that, they just align. So you remove the UIM, and you tap the outlet, and put a plug in it. It is the uppermost plug in this pic, brass colored. The plug that is on the right side is in the heater outlet, which is already tapped, but don't plug that one, this was just for a simple mockup.
As for headers, all I need is time. In order to build them I need my own Fiero with a 3.4L DOHC, and this will take some time. I don't know yet whether I am going to build the motor first, or get a 88GT first. If one comes around that I like, I'll buy it, but so far none have cought my liking. Keep an eye out for my ITB intake, the dyno numbers will tell all. And it will give much better midrange than the DOHC short runner since the runners are much longer. I expect a power curve of 4500-7500 or even 8.
------------------ 1992 Lumina Z34 5-speed For Sale, modified(high 13s), or stock 14.78 @ 92.68 1992 Lumina Z34 5-speed Stock, new crate engine and trannsmission 3.4L TDC V6, getting built to about 430hp at 8000rpm for a 88GT
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03:44 PM
AaronZ34 Member
Posts: 2322 From: Colorado Springs, CO Registered: Oct 2004
Forgot to mention. The rest of the LIM just blocks off the coolant lines, so all you need is a flange that blocks them off. I cut up a spare LIM that I had for the T-stat housing, and that will be included with my ITB setup. For my SC engine, I am going to build another LIM, using mandrel bent rectangular piping (BIG $$$ there), and I will be building that T-stat housing custom. The motor will have a T-stat incorporated into the electric water pump, so I no longer need a housing. I will run a single line from each head, and Y them together, with a bung for the heater line. Now I can make a single piece flange, which will support boost pressure much better.
can't wait to get mine in and start tinkering with the cam timing with my new tool... gonna hold off on going turbo till next year, so i'll have some time to play with NA power on a stock engine with a freeflowing exhaust and possibly a hollow plenum.
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07:54 AM
AaronZ34 Member
Posts: 2322 From: Colorado Springs, CO Registered: Oct 2004
Pros- The sound. It screams. It turns heads anywhere above 3500rpm. The wide power band. Its hard to describe the feeling of a motor that just doesn't stop pulling. Fuel economy. I get better mileage than the 2.8 from a larger more powerful engine. High 13 low 14 second motor -stock
Cons- Feeling the need to drive it like you stole it to get maximum performance Higher maintinance costs, but pretty insignificant really. Its a loud motor, hard to get around that with a 2.5" exhaust system.
Biggest con, never being able to resist the urge to drive it like you stole it
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11:12 AM
crzyone Member
Posts: 3571 From: Alberta, Canada Registered: Dec 2000
I just ordered a spec stage 3 clutch, the stock fiero replacement clutch bit the dust. Makes some interesting sounds when I push the clutch in, like a bunch of clutch material banging around in the bellhousing...
So fiero is out of commission for a few weeks. Ah well. Got 7000 hard miles out of a stock fiero clutch, not bad I guess. Now I will be able to drive it much harder with a clutch I know will hold.
Going to pretty up the engine when I have it out as well, I never intended the engine to stay in the car the last time I put it in. But it got cold outside so I left it in and drove it as is.
Have your car on the road yet?
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01:13 PM
fieromadman Member
Posts: 2217 From: Oconomowoc WI, USA Registered: Jan 2003
yes, its been prooven several times that stock fiero clutches dont hold up to the 3.4 dohc, listening darth? I like driving it like i stole it except for when it does this crumby misfire crap. For some reason my engine doesnt want to pull high rpms smoothly. i think that either fuel or ignition is to blame as it seems down on power and its un-smooth.
I just ordered a spec stage 3 clutch, the stock fiero replacement clutch bit the dust. Makes some interesting sounds when I push the clutch in, like a bunch of clutch material banging around in the bellhousing...
well you may want the stronger clutch anyways but I've had this happen to me before and in my case it was a couple flywheel bolts backed their way out and were tapping the clutch disk when the clutch was in (so that the clutch and the flywheel weren't moving together) some locktite and a retorque and they were fine - but at the time it sounded almost like a rod knock
i should mention though that i will never run a stock clutch even on a stock engine again - i've destroyed tomany (an no i never glazed them or burned them up - they actually failed, rather drasticly)
[This message has been edited by Kohburn (edited 02-28-2005).]
I will be using a stock clutch on my red Z34, just a factory replacement from Advanced Auto. I have used them before, and even how I drive they hold up pretty well.
The clutch in my white car, although not a stocker, looked brand new after 9,000 miles of racing the piss out of it. I am pretty easy on clutches tho, even when racing. Maybe the 284 clutches last longer I don't know (they are bigger IIRC).
I will be using a stock clutch on my red Z34, just a factory replacement from Advanced Auto. I have used them before, and even how I drive they hold up pretty well.
The clutch in my white car, although not a stocker, looked brand new after 9,000 miles of racing the piss out of it. I am pretty easy on clutches tho, even when racing. Maybe the 284 clutches last longer I don't know (they are bigger IIRC).
I've had two main failures.. one the presure plate diaphram finger snapped off and shreded the clutch material in a matter of 20 miles the other the damper springs worked out of the disk and jammed the clutch on forcing me to drive with no clutch (was better than the first type because i could still drive - only hard part was turning off the car when i had to stop and using the starter to get moving)
haven't had any problems with stronger clutches
I really don't think FWD clutched take the same loading as rwd clutches - fiero clutch takes a lot of load launching with all the traction it gets.. IMO
[This message has been edited by Kohburn (edited 02-28-2005).]
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06:47 PM
AaronZ34 Member
Posts: 2322 From: Colorado Springs, CO Registered: Oct 2004
Yes that is true but the FWD has a lot harder time under part throttle, everyday driving becuz of the 1000+ additional pounds. I've never had a bad failure like that in any of my Getrags, but I have had clutches wear down abnormally fast (when I was first learnign how to drive it).
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08:35 PM
Mar 1st, 2005
fieromadman Member
Posts: 2217 From: Oconomowoc WI, USA Registered: Jan 2003
it was acting up before i put on the wires, i tried the wires to see if they would fix it.. i think that it is a fuel problem. Time to pull some plugs to see if im rich or lean. The scan tool showed 100 for the lt fuel trim i think... where is it supposed to be?
it was acting up before i put on the wires, i tried the wires to see if they would fix it.. i think that it is a fuel problem. Time to pull some plugs to see if im rich or lean. The scan tool showed 100 for the lt fuel trim i think... where is it supposed to be?
just curious but did you replace the O2 sensor when you swapped in the engine? trying to think of various things that can cause that - I suppose the fuel tables on the chip just might need tweaking..
Yes that is true but the FWD has a lot harder time under part throttle, everyday driving becuz of the 1000+ additional pounds. I've never had a bad failure like that in any of my Getrags, but I have had clutches wear down abnormally fast (when I was first learnign how to drive it).
this is what happens to me with stock clutches
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07:23 PM
Mar 2nd, 2005
fieromadman Member
Posts: 2217 From: Oconomowoc WI, USA Registered: Jan 2003
No i didnt replace the o2 sensor when i put in the motor, but i was thinking, isnt the o2 snsor only used when the car is floored? well i have this happening all of the time. Can it still be connected? dont they usually run rich anyhow? I dont think that the chip would be at fault, because it has been on there for months before the car started doing this. What is the deal with the FPR on these motors? I would actually like to replace mine with an adjustable one anyhow. Im thinking that this weekend im gonna change the fuel filter and plugs and see if that helps at all. If that doesnt then i might get my coils tested. If that doesnt do it, ill swap in the stock chip. if that doesnt do it, im gonna check my plug wires (even though thier new). If that doesnt do it then i'll check my fuel pressure (fuel pump is new 2 yrs ago and professionally installed). If that doesnt do it then ill change theo2 sensor (it should be running rich if thats bad though, id think anyhow) and if that doesnt do it im gonna drive the car off a cliff.
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12:47 AM
Fieroking Member
Posts: 2148 From: Coeur D Alene Idaho USA Registered: Jun 2002
didn't even think of the fuel filter - that'll definately cause problems with revving as would a fuel pump thats on its way out and not quite keeping up.. but you said that was new - I went with a walbro so i shouldn't have to worry
[This message has been edited by Kohburn (edited 03-02-2005).]
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06:34 AM
Will Member
Posts: 14252 From: Where you least expect me Registered: Jun 2000
No i didnt replace the o2 sensor when i put in the motor, but i was thinking, isnt the o2 snsor only used when the car is floored? well i have this happening all of the time. Can it still be connected? dont they usually run rich anyhow? I dont think that the chip would be at fault, because it has been on there for months before the car started doing this. What is the deal with the FPR on these motors? I would actually like to replace mine with an adjustable one anyhow. Im thinking that this weekend im gonna change the fuel filter and plugs and see if that helps at all. If that doesnt then i might get my coils tested. If that doesnt do it, ill swap in the stock chip. if that doesnt do it, im gonna check my plug wires (even though thier new). If that doesnt do it then i'll check my fuel pressure (fuel pump is new 2 yrs ago and professionally installed). If that doesnt do it then ill change theo2 sensor (it should be running rich if thats bad though, id think anyhow) and if that doesnt do it im gonna drive the car off a cliff.
Exactly the opposite. The O2 is NOT used only when the car is floored.
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09:01 AM
joshua riedl Member
Posts: 1426 From: watertown wi USA Registered: Jan 2004
the o2 sensor was reading good the day you brought it over. we can check it again if you want though. i suppose just because it's reading doesn't mean it's correct.
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09:44 AM
AaronZ34 Member
Posts: 2322 From: Colorado Springs, CO Registered: Oct 2004
how much bottle can a 3.4 dohc take. and does any one have a good install on how to do the exaust timming retard.
I saw one running a 75 shot at the track. Pretty sorry that my Z34 was only running 2 tenths slower without N2O. But that is risky, I'd keep it at a wet 50 shot. Go to www.60degreev6.com and there are a few writeups on cam timing.
------------------ 1988GT 5-speed Black with grey leather, I pick it up this May! 1992 Lumina Z34 5-speed 14.78 @ 92.688, high 13s at sea level 1992 Lumina Z34 5-speed Stock, new crate engine and trannsmission
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11:34 AM
Mar 3rd, 2005
fieromadman Member
Posts: 2217 From: Oconomowoc WI, USA Registered: Jan 2003
i really need to get to the bottom of my problem. Its pissing me off, this whole week has been absolute crap.
What did the terminals on your coils look like when you changed your plug wires? They can have rust on them and cause problems. Could be bad/dirty/old plugs. Does the car start hard too?
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01:19 AM
Mar 4th, 2005
fieromadman Member
Posts: 2217 From: Oconomowoc WI, USA Registered: Jan 2003
starts perfectly normal.. i actually drove it today for the first time since last weekend and it felt pretty solid, so maybe it took care of its-self/it was in my head in the first place. It seems to have more viabration at higher rpm than it used to though, which is prolly why i thought that it was firing un-even. It might just be because my mounts are all like in perfect condition finally so it just makes it seem like its viabrating more. i dont know, there still might be something wrong with it, but we'll see. I'm still gonna do somebasic maintance and look at the plugs, change the fuel filter, check those coils etc.. maybe there is something wrong.. who knows. Anyone know where i could pick up and adjustable FPR?
you can buy an inline adjustable fuel pressure regulator and put it in the return line after the stock FPR. can't remember if you need to disable the stock one or not for that to work.
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07:21 AM
Mar 5th, 2005
fieromadman Member
Posts: 2217 From: Oconomowoc WI, USA Registered: Jan 2003
hmmm.. i would like to just eliminate the stock one and put that in there anyhow, maybe when i have time to look at it closer in my manual ill see if this works.
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06:42 PM
May 3rd, 2005
85frankenstein Member
Posts: 687 From: Kenosha, WI 53142 Registered: Nov 2001
It's been requested that I include this thread on the DOHCFiero website because of it's content. I've already got Cliff's blessing, but I also want to make sure that all of the participants in this thread feel comfortable with it. Like I've said before in other threads, I try to avoid sponging content from other sites, but I feel that many of the comparisons along with other data is pertinant to the build and probably very hard to get everyone to participate any other way. Is there any participant in this thread that has a problem with utilizing it on the DOHCFiero website?
Although I've already told you in an email that you have my blessing to use anything I have said here, I'd just like to make it public by saying it again; you are welcomed to use anything you like or that's helpful in this thread as far as I'm concerned. It'd be really nice to think that maybe something in here can or will help someone with this swap or help their decision to do or not do this swap.
------------------
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11:59 PM
May 4th, 2005
fieromadman Member
Posts: 2217 From: Oconomowoc WI, USA Registered: Jan 2003
It's been requested that I include this thread on the DOHCFiero website because of it's content. I've already got Cliff's blessing, but I also want to make sure that all of the participants in this thread feel comfortable with it. Like I've said before in other threads, I try to avoid sponging content from other sites, but I feel that many of the comparisons along with other data is pertinant to the build and probably very hard to get everyone to participate any other way. Is there any participant in this thread that has a problem with utilizing it on the DOHCFiero website?
Bob
feel free to make anything I say publicly known
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08:19 AM
85frankenstein Member
Posts: 687 From: Kenosha, WI 53142 Registered: Nov 2001
Thanks for the permission! I think a lot of this discussion would fit very well under the FAQ section which hasn't been worked on at all.... If you think anything else will fit there, send it on over as well...
fieromadman:
Something tells me that once this thing is put together, dialed in, and broken in, there's going to be a lot of rides in this car! It should be a screamer.
or when I win the lottery. I think that this motor has the potential for 450 horsepower turboed if built right.
I like driving it like i stole it except for when it does this crumby misfire crap. For some reason my engine doesnt want to pull high rpms smoothly. i think that either fuel or ignition is to blame as it seems down on power and its un-smooth.
