13.9? From a 4.9? (Page 9/17)
86fieroEarl AUG 13, 08:02 AM

quote
Originally posted by AaronZ34:


Not EXACTLY, but close. The 3.4 DOHC, with the factory 4T60e gearing, using my stock dyno, has near perfect shift points from the factory, at just over 6500. But fact remains, that is close enough to redline. But yes, the DOHC does like the manuals.

4.9 auto vs 3.4 auto, the 4.9 will have a big advantage off the line, but from there on out every advantage is in the DOHC's hands. It would be a closer race, but in 1/4mi distance I think the 3.4 can overcome its poor off the line performance. And besides, a simple torque converter would change that race A LOT.

And Mizer, I gave ya a plus cuz I can't stand one more member getting banned from this stupid ratings thing.


I have to dissagree with everyone saying a 3.4 is dead even with a 4.9... A auto powered 3.4 is horrible (specially the one I test drove) It also could of been the fact the 3.4 was probally running behind a higher geared transmission ( I don't know)

When I drove this 3.4 it felt powerless compaired to the 4.9 I drove before I decided to go with a 4.9. At that time the test drive between them both was not fair I know. I loved the way the 3.4 sounded and looked in the engine bay of a fiero.... But at the time my fiero was a automatic and there was no way I was going to mate a 3.4dohc engine to it.


You can turbo charge a 3.4 and make it faster then a 4.9, But you can do the same to a 4.9, In the case of a 3.4 you would want a turbo to spool quicker to help it's torc, On the other hand you would need a slower spooling turbo to help the 4.9 in the higher RPM band.


In my opinion at the end of all the modifications the 4.9 will still beat the 3.4 hands down. A 4.9 really doesn't need much in mods to be competative. I also highly dislike the timming belts on a 3.4 dohc engine and the weight.


Anyway I have respect for all fieros with engine swaps , quad 4, 3800sc, SBC, LT1, LS1, 4.5, 4.9 ,ecotech, 3.4 pushrod, 3.4dohc, and any others if I missed any. The point to this is all of these swaps can be made to go fast, Some have advantages over others. The LS1 will have a huge advantage over all these swaps in my opinion.

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4.9 under construction... To lay the smack down on any mid 80s truck that stands in my way.

[This message has been edited by 86fieroEarl (edited 08-13-2005).]

AaronZ34 AUG 13, 12:55 PM
The auto 3.4s are just as fast as the 5-speeds once they get going. Off the line is where they have most of their problems, but after that, they are pretty similiar. The shifts hurt autos more, but the 3.4 has surprising midrange to make up for it. The one you drove must have had problems.

A turbo 3.4 will walk all over a turbo 4.9, at half the boost. The 4 valve ehads eat up boost like you couldn't imagine. And in the case of a 3.4 I'd want the turbo to spool at 3500, holding to 7k. I don't turbocharge cars for low end torque, few people do. I bet both engines require a very similiar compressor, the 4.9 has more displacement, but the 3.4 has much more efficient heads.

There is no way a 4.9 will beat a 3.4 when both are highly modded. Displacement is key yes, but when your heads suck as much as the 4.9s do, you have a huge disadvantage. A fully ported/polished set of 4.9 heads with larger valves won't flow what our heads do stock. Why do you dislike the timing belts? Is $150 every 60,000 miles too much?

But, I am not here to argue 3.4 vs 4.9, I was simply here to express my disgust with everything MTA has laid his hands on. including the dimes.

crzyone AUG 13, 02:55 PM
I imagine a 4.9 will feel much faster than a 3.4. The 275lb/ft will put you back in your seat, and the sound will roar. The only problem with a stock 4.9 is that it runs out of breath, the torque falls off quickly as rpm's rise.

A 3.4 will feel much like a stock 2.8 in low rpm's. When it hits 3500rpm, it is then in its powerband and will pull hard to 6500rpm or so. It never gets above 220lb/ft, it doesn't really have that put you back in your seat feel. It holds its peak torque longer than a 4.9, and after 3500-4000rpms or so, the 3.4dohc has more torque than a 4.9.

The 3.4dohc is only as fast as a 4.9 in the 1/4 because it can use the shorter gears longer, and had more torque up high than a 4.9.

As far as modifications go to each motor, you can go as fast as your pocketbook. Most of the turbo 3.4's are using small innefficient turbos that do not suit the motor. With an GT35R and an intercooler, the 3.4 will easily make 300whp. Only problem with that is cost, most just use an old GN turbo and no intercooler.

Rockcrawl has showed that headwork, a cam and some roller rockers will get a 4.9 into the low 13s, which is very respectable. PJB has shown a turbo 4.9 can be in the low 12s, with a diesel turbo no less.

GmetalGT AUG 13, 04:52 PM
Hello every one, My name is Chris, and I still have an unreliable 4.9 Fiero.
crzyone AUG 13, 06:12 PM
WB Chris, too bad you couldn't get your old password.

I doubt MTA will come back to this thread, especially now...
AaronZ34 AUG 13, 06:41 PM
Yah I think he realizes that he is quickly getting more people against him by the minute.

I don't despise the 4.9, it has its positives, but it is not my cup of tea. It does things a 3.4 never will--such as sounding like a V8.

Rhino88gt AUG 13, 08:01 PM

quote
Originally posted by crzyone:

PJB has shown a turbo 4.9 can be in the low 12s, with a diesel turbo no less.


And I hope to better that time with it in my car, hehehe!!! Im not gonna run the intercooler he used at first I dont think. But later on Im gonna have the local tuning shop (Street & Strip Performance) switch it over to the cyclone program and have it dyno tuned with the intercooler. THEN I might crank up the boost for even more power.

crzyone AUG 13, 08:07 PM
They are expensive, but you should consider an air/water intercooler. PWR's barrel type intercoolers are probibly the easiest way to efficiently intercool in a fiero. Run a small rad up front with a couple liquid lines and a small pump, all of which I'm sure are included.

http://www.pwr-performance.com/intercooler.htm

Lowers intake temps which adds power and prevents detonation.

Edit to add a picture of Rockcrawl's pwr barrel intercooled N*

[This message has been edited by crzyone (edited 08-13-2005).]

86fieroEarl AUG 13, 08:34 PM
hmm seem to pick up more negs..... Oh well, I guess ppl rate others on opinions If that was the case I would throw a few negs at certain ppl, But I haven't done that and if I do I will atleast have a backbone to tell you if I rate you a neg


My opinion still stands and im entitled to have it.... Until I get a ride or test drive a 3.4dohc engine fiero that proves to be faster or feel faster then the 3.4 I drove........ my opinion will stay the same


Have a nice day.

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4.9 under construction... To lay the smack down on any mid 80s truck that stands in my way.

[This message has been edited by 86fieroEarl (edited 08-13-2005).]

crzyone AUG 13, 09:19 PM

quote
Originally posted by 86fieroEarl:

hmm seem to pick up more negs..... Oh well, I guess ppl rate others on opinions If that was the case I would throw a few negs at certain ppl, But I haven't done that and if I do I will atleast have a backbone to tell you if I rate you a neg



Of course jumping in this thread to fling insults is only your opinion...