raemore Posted May 22, 2013 Report Share Posted May 22, 2013 Hi.. Does any one know if there are any aftermarket performance parts for the dohc 3.4 motor. Somebody must be doing somthing to them...... stainless headers.... comtroller tweaks......? awsome little motor though.... /alex Quote Link to comment Share on other sites More sharing options...
Psych0matt Posted May 22, 2013 Report Share Posted May 22, 2013 Not really, as the newest one is 16 years old. However, there's always a chip, CAI, or if you can find one an FFP underdrive pulley, poly dogbones, cam work, timing work, exhaust work, etc Quote Link to comment Share on other sites More sharing options...
z34Phoenix Posted May 22, 2013 Report Share Posted May 22, 2013 back in the day there wasn't much and now pretty much nothing. I know there is a site called http://www.milzymotorsports.com/ that has headers for the 96-97 DOHC's. Your PCM is not able to be rewritten if you had a 96-97 it could have been. I had done quite a bit of tuning on my old 96 DOHC. I never noticed much of a gain from the under drive pulley. I sold the one i had a few years ago anyway and the al engine mount can be fab'd up by using a simple piece of aluminum bar stock that i got from home depot. about 1/8" thick and 2" wide. drill two holes and done. there is enough flex in it to not be 100% solid and also i never had an issue or failure from metal fatigue. Suggestions i would make would be: -swapping to a 96-97 intake manifold and TB. the longer runners increases low end tq and still has plenty of flow to allow the same amount of top hp. -I ported the upper and lower intake and tb and saw great gains. but i would be careful about major changes to flow without a solution to tuning. -I saw a nice improvement from swapping to a 2.5" exhaust from the down pipe back. -If you want further gains i would recommend swapping to a 96 obd2 system and swapping pcms. that way you can be tuned and get more power from the car. -The gear swap i had done made the car pull very strong too. IIRC it was basically swapping the outer section of the diff with one from a 3100 series 4t60e trans. -deff need a cold air intake. i hope this helps. Quote Link to comment Share on other sites More sharing options...
jman093 Posted May 22, 2013 Report Share Posted May 22, 2013 back in the day there wasn't much and now pretty much nothing. I know there is a site called http://www.milzymotorsports.com/ that has headers for the 96-97 DOHC's. Your PCM is not able to be rewritten if you had a 96-97 it could have been. I had done quite a bit of tuning on my old 96 DOHC. I never noticed much of a gain from the under drive pulley. I sold the one i had a few years ago anyway and the al engine mount can be fab'd up by using a simple piece of aluminum bar stock that i got from home depot. about 1/8" thick and 2" wide. drill two holes and done. there is enough flex in it to not be 100% solid and also i never had an issue or failure from metal fatigue. Suggestions i would make would be: -swapping to a 96-97 intake manifold and TB. the longer runners increases low end tq and still has plenty of flow to allow the same amount of top hp. -I ported the upper and lower intake and tb and saw great gains. but i would be careful about major changes to flow without a solution to tuning. -I saw a nice improvement from swapping to a 2.5" exhaust from the down pipe back. -If you want further gains i would recommend swapping to a 96 obd2 system and swapping pcms. that way you can be tuned and get more power from the car. -The gear swap i had done made the car pull very strong too. IIRC it was basically swapping the outer section of the diff with one from a 3100 series 4t60e trans. -deff need a cold air intake. i hope this helps. Do you still have your .bin files from your LQ1? Quote Link to comment Share on other sites More sharing options...
z34Phoenix Posted May 23, 2013 Report Share Posted May 23, 2013 Yup I sure do. Quote Link to comment Share on other sites More sharing options...
pshojo Posted May 23, 2013 Report Share Posted May 23, 2013 IIRC, if you swap intake manifolds, the matching holes are different so you would need to swap lower intake and possibly heads with the swap? I had my 95 DOHC reprogrammed by GMTUNERS.com. He did help shift points and little extra for $60. Gear swap seems interesting. The DOHC came with 3:41ish gear ratio, did you raise or lower your ratio? Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted May 23, 2013 Report Share Posted May 23, 2013 UIM and LIM need to be kept as a set, but either set will bolt to either head design. Quote Link to comment Share on other sites More sharing options...
z34Phoenix Posted May 23, 2013 Report Share Posted May 23, 2013 Yes the lower intakes are diff too between 95 and 96+ I ended up with a 3.73 gear ratio. And with the smaller wider tires I ran it was as if I had a 4.10 ratio if I were on stock size tires. With the tuning I do mail order for the DOHC's. I do a good bit of work to the spark table that greatly increases low to mid range tq. And remapped shift points help to get you right in the sweet spot when you get on it. This engine has/had so much potential. The only reason I did the swap is that parts are getting hard and hard to find. Also being able to go boost gives me more power for a lot less money. Quote Link to comment Share on other sites More sharing options...
pshojo Posted May 23, 2013 Report Share Posted May 23, 2013 That is why I did swap in my DD, however my vert I'm trying to keep my stock. So I'm keeping DOHC, since I have two of these engines around. Quote Link to comment Share on other sites More sharing options...
gambler87 Posted January 4, 2014 Report Share Posted January 4, 2014 Z34 phoenix What was your tire size? And also what gear ratio did u throw in? My 96 came with a 3:43 gear ratio Sent from my MB886 using Tapatalk Quote Link to comment Share on other sites More sharing options...
z34Phoenix Posted January 19, 2014 Report Share Posted January 19, 2014 Like posted above I ran a 3.73 gear ratio. Tire size was and still is 245/45-17. The wider foot print and small dia tire helps. The smaller dia changes my final drive. To get the same effec I would need to run a 4.10 on stock tires Quote Link to comment Share on other sites More sharing options...
gambler87 Posted January 19, 2014 Report Share Posted January 19, 2014 (edited) Google search 3.4 Dohc short runner intake. Mine has a 75mm north star throttle body on it. I also have gasket matched heads, lower manifold, and upper plenum. I also bellmouth the part of the upper plenum that has the 3.5" pipe welded to it. I also have a ls1 MAF. SLR (Steve Long Racing) regrinds camshafts for the 3.4 Dohc. I have a full set of those but they do require an injector upgrade and tune. FFP under drive pulley. They are hard to find but I just out one on my gtp. U can find them on the Fiero forums every now and then. JE pistons. I have the spec sheet for 10.5:1 pistons. When I bought mine for my 97 Fiero 3.4 Dohc. They cost me $1,200 for six with rings. They are a OEM replacement forged. Which means a low expansion piston. Milzy motorsports is the only header manufacture for the wbody. I talked to him last week about making me a set of headers. They are still for sale and he said they would take about a month to make and would be $1,200 for the set. They are stainless ceramic coated with a 3" downpipe that deletes the cat. I'm in the process of doing the Z34phoenix diff change to my 96. WOTTECH has the ability to have head studs, mainstuds, rod bolts (all are ARP). He also can get stainless valves which he says doesn't flow as much as stock ones. And can get aftermarket springs to run big regrinds. And can get lock and retainers. I also have made what I call an exhaust manifold flip adapter, which let's u use a 96-97 front exhaust manifold on the rear head of the motor. 91-95 motors u can do this without needing a adapter but 96-97 u can't as the exhaust ports won't match up with the manifold. I know the Fiero people like them because they can run stock routing of the Fiero exhaust on the "hi flow" swap. I would suspect that the w body people would use them for running a turbo on the 96-97 motors. That is all of the aftermarket that I have found in about four years of building now two of these motors. Both will be running in the spring I hope this all helps someone Sent from my MB886 using Tapatalk Edited January 19, 2014 by gambler87 Quote Link to comment Share on other sites More sharing options...
pshojo Posted January 20, 2014 Report Share Posted January 20, 2014 Wow, impressive, what did cam regtind set you back? Have idea what hp you'll be running? Spare parts? Quote Link to comment Share on other sites More sharing options...
gambler87 Posted January 20, 2014 Report Share Posted January 20, 2014 The regrinds set me back $434 that included shipping Sent from my MB886 using Tapatalk Quote Link to comment Share on other sites More sharing options...
gambler87 Posted January 20, 2014 Report Share Posted January 20, 2014 There was a guy that had SLR cams and the tuned intake and an UDP and he had 275 at the wheels but that was with a stick. I will hopefully be dynoing it this spring Sent from my MB886 using Tapatalk Quote Link to comment Share on other sites More sharing options...
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