I have a 96 #.4 dohc in a 87 GT with the getrag. It is fun, But I have to agree wuith Aaron, the pwer does fall off at around 6500 rpms in stock form. I dont know by how much, but it just always seems better to shift at around 64-6500 and slam into the next gear right back at the beginning of the powerband. It always worked better for me to stay in the middle of the powerband than run to the very end.

Just reading this post it seems as if everybody is arguing of each others definitions. Example, Aaron said the dohc wasn't a rev motor. maybe he thinks a rev motor should make power steadily as the rpm rises, and be able to withstand constant high rpms power. dave said that it is a rev motor. Maybe dave thinks a rev enginet can rev high and still make enough power to actually propel the car. Just from looking at the dyno charts, the 3.4's powerband does fall off in the 6k range, however it is still making enough power to steadily accelerate in a Fiero. Looking at Dave's defintion, the 2.8 with a turbo is a rev motor.

The lowend on this motor is strong, it will spin tires for days, but so did my 2.8. In fact my dohc feels like a strong 2.8 right up until 3500 rpms. After that there is no comparison. I remember in the 2.8 I would have to shift @ 5-55K or I would be just making noise. The dohc will keep going a ways further.

A stick in a Fiero, period, in my opinion does not suck, but does not suit my spirited driving habbits. I have owned an auto, and I would constanly drive it like it was an stick. Heck even the 2.8 feels zippier with a stick than it does with the auto. What turned me on most about this engine is that it already can rev to 7k, is more powerful, and spreads the power out better than most other swaps. This seems to be suited for a control freak...Maybe even a person who is indecisive....Never knowing what gear he wants to be in, but still wants to go. I like to be able, like Exotic Rida said, downshift into a stupid low gear coast through a corner, and get hard on the gas and have all the gears to build speed with again.

The 4.9 was nice but I kept hearing how it just would not rev. Spirited driving and that engine to me would not go with my 5spd too well. In fact a at first boought this engine, and took it back and got my dohc. from what I hear, the 4.9 is justa as easy if not easier than the dohc swap. I think it will also cost less.

So in short, it depends on your driving style....Whether or not to use any engine behind any tranny. If you like to get involved....all the time, manual. if you want a car that is faster than the 2.8, when you fell like flexing some, but still be able to cruise and just chill out, auto.

I agree with most everything you said.

My thoughts on the DOHC, it is a rev motor from the factory, but some people were just exagerrating it. We all know the mid rnage (3500-5500) is very strong on this motor, btu the high side (6000+), isn't. You have a 96 motor, so you have a bit more on the top end since most of us are running 91-95 motors. It is a high revving motor no doubt, but the power isn'tall up high, that is what I was trying to get at. The motor I am building in my sig, that will be a true high revving motor IMHO, where all of the power is from 4500 on, and there isn't much below that.

Mine seemed to pull hard right to 7000rpm, no noticable drop off. I would pass on the highway in 3rd gear and would shift into 4th at 7000rpm which was around 110mph. I would have had to get it on a dyno to see how hard the power fell off.

In 1st and 2nd gear I would bounce off the rev limiter because the motor just seemed to never run out of power. The previous owner of my engine said they had done some "performance" mods to the motor... I don't know if thats true or not but I had assumed they did a 13* exhaust cam retard. Power below 3500rpm was like the stock 2.8 but power above was like a light switch.

A rev motor tends to make it's power above where the normal pushrod engine does.
Again Aaron all your responses skip over the cam retard which does make power above 5500. How many times does this have to be said before you hear it? The cam retard, custom exhaust that must be used to be in a Fiero all contribute to the engine easily pulling on the high end. Not to mention that the engine has a lot less mass to pull than originally. Even without those things this engine is so much sweeter with a manual that I can't even believe you're arguing here about this. The auto Lumis are just a yawn fest where as the manual makes thie engine come alive. If you still don't afree then lets just agree to disagree and let it lie already.

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ease up dave, maybe his custom made, perfectly tuned pin-hole filled headers are killing his top end.

quote Originally posted by crzyone: Mine seemed to pull hard right to 7000rpm, no noticable drop off. I would pass on the highway in 3rd gear and would shift into 4th at 7000rpm which was around 110mph. I would have had to get it on a dyno to see how hard the power fell off. In 1st and 2nd gear I would bounce off the rev limiter because the motor just seemed to never run out of power. The previous owner of my engine said they had done some "performance" mods to the motor... I don't know if thats true or not but I had assumed they did a 13* exhaust cam retard. Power below 3500rpm was like the stock 2.8 but power above was like a light switch.

I'll admit it feels like there is little drop off, even in a Lumina. But once on a dyno, you'd be shocked at how far is falls off. Below 3500 it should feel a lot like the 2.8, but it really is making more tq, and at 3500 there is a huge torque jump (20wtq), and the hp curve follows suite. On my white car this same curve came in, just at 4000rpm, and the fuel curve went lean at the same time.

quote Originally posted by AaronZ34: Unfortunately, no other component of my car was tuned at 6800rpm. And no, they aren't killing my top end. The air they flow is, becuz the chip isn't even remotely tuned for them, the ECU can't figure out why the **** the exhaust gets out so fast, and can't register it going pig rich at 6000+ rpm.

sounds to me like your problems with the 3.4 TDC engine are caused by your unwillingness to properly tune the motor.. seriously dude.. get yoru **** together, tuned, THEN talk about it's powerband. everyone else's 3.4 TDC pulls hard to 7k rpm.. so obviously there is soemthing wrong with yours

I do believe power falls off at high rpm, but with a manual transmission and a light car its hard to feel it. Thats why I said I would have to be on a dyno to see it drop off. My butt dyno isn't that accurate.

85 GT Larry... The origional poster of this topic... When you get a chance, Perhaps you should stop by Las Vegas Fiero club (located on alto, a block east of nellis you cant miss it) and discuss what you would like to do with your car with them. Or I, since I have done both swaps. Currently I drive an 88GT with a 3.4 Camaro engine with a 5 speed.

quote Originally posted by aaronrus: sounds to me like your problems with the 3.4 TDC engine are caused by your unwillingness to properly tune the motor.. seriously dude.. get yoru **** together, tuned, THEN talk about it's powerband. everyone else's 3.4 TDC pulls hard to 7k rpm.. so obviously there is soemthing wrong with yours

Sounds to me like you can't ****ing read. I have 2 Z34s, both 5-speeds, one stock, one modified. The stock one fell off badly after 5500, and it is a brand new crate motor, highest stock dyno I've ever seen a 3.4 pull, and an a:f at 13:1 from start to finish. My modified one wasn't tuned, but still made 40whp more than stock, with less high rpm fall off, but it still fell off. And it wasn't tuned, but the a:f was ok, not good, but not bad enough to hamr the motor (ranged from 11.5:1 with some 12.5:1 peaks, at 6500rpm on, it was under 10:1. No one here has a car that doesn't fall off to 7000, it takes cam timing, new intake manifolds, and headers.

I dont know, but I never bounced my 2.8 off the rev limiter. I just did again tonight in my 88 DOHC, Got going in a turn in 1st and floored it, ran straight to limit and shut off, then back on again before I got to shifing. It may be noticable in 3rd or 4th, but 1st definitly not, and I dont think so in 2nd either, but 2nd is long enough I can be ready to shift before it actualy shuts off.

Yah the power that the 3.4 makes, mixed with the low weight of the Fiero, makes feeling it really hard. Even in the Z34 you really can't notice it until 3rd and 4th gears. But that doesn't change the fact that the engine is dropping power, it most certainly is, but it is hard to tell. A few cheap ways to lessen the drop off:

Get a chip from Ben, www.60degreev6.com/store . He has been tuning the DOHC for a long time now, and has sat on the dyno to get the best results. His chip helps throughout the powerband, but really helps after 6000.

A cold air intake will help power tremendously on the 3.4, at all RPMs.

The 96+ intakes helped the most by far that I have done, my line barely dropped off to 6500, where $hit hit the fan as far as I'm concerned. But the cam timing will help more than the intakes, but I have no experience with it yet.