How would you get 250 rwhp?

[crytical point]

I would like to install a 3X00 into my Fiero and use a 4t60 but I would like about 250 at the wheels to give me the performance I would like. I have been reading this forum for a while now and I have seen so many ways to get power out of these engines that it is hard to choose. So I would like to ask every one how to get that much power out of a 3X00 and keep it reliable enough to drive daily. My Fiero has the stock anchor 2.8 and I hate it more than anything because my 2.0 cosworth vega puts more power and tq to the wheels (180hp 190tq) and my girlfriends 85 rx7 with a 1.2L rotary would smoke me in almost any condition. If there is an effective way to make that much power with out loosing driveability or bolting a turbo or supercharger on because I am tight on space then I would like to hear it.

[El_Diablo]

to keep it reliable i would deffinetly go with a turbo and you wont lose any space at all if you mount it in place of the muffler

if not i would look at the 3500 to start at for a base, your deffinetly going to want to look at a cam, heads and intakes though, you should be able to use a powertuner to run a w-body bin file for the 3400 and modify it a lil to work with the 3500, but of course this would require swapping to an obd2 setup... but i doubt you'll get the performance out of one of these engines without doing so, its just the best way to go about it IMO

[sil]

heh those rx7's sure do boogy

hard to keep it strait with a turbo even with 255's on the back
there so darn light

onsubject:

what he said ^^
turbo a 3400 or 3500 with a not so huge cam will give you enough power to please you
cant say much about obd2 cuase i have no exp in those ecu's
but i hear its a much better system to work with

but ya, you wont need alot of work done to the motor, jsut turbo and tune tune tune some more

[geoffinbc]

You don't need a turbo 3500 to make 250HP you can do that with simple mods and keep it N/A and streetable. There is 300 HP 3X00's rolling around on this board right now.

If I were to do a buildup this would be my suggestion. Since this will be an N/A build you will want to stick to the old adage "There is no replacement for displacement." So start with at least a 3500. Keep the bottom end stock and don't mess with the pistons either, assuming this engine is in good working order. The heads flow very well but I would gasket match them and the intake manifold. I would also smooth all the runners in the intake. Install a TCE throttle body to work with your old cable system as well. Do any blending required in this area to smooth out intake flow. Next address the cam. This will be key to making power. Since the car is old you don't have to worry about emissions, anything a tuned up 3500 will spew out will pass emissions as long as the cat is in place. Rocker arms are an option but not necessary in the least. Headers will also be requirement since the manifolds from a 3500 wont work anyway. This should get you most of the way but the last key will be ECM choice. The OBDII systems are very well hacked and programmable. But the after market systems offer more user friendly software and a good company support system. They also come with clear instructions for installation. This is your choice and it will depend on your confidence with these systems and budget.

Stock 3500's are making over 200HP today in production vehicles. To get another 50 or 60 HP is not going to be that hard. Considering stock vehicles are toned down due to emissions, have crappy exhaust and production casting flaws with low lift and duration cams.

[Superdave]

Here is how to get over 270 WHP out of a 3500.. http://www.v6z24.com/registry/whitelightning2/


Not very streetable but it sure is fun!

[SappySE107]

250 whp is not 250 hp though if you are comparing to 200 stock. Boost is the easiest solution, if adding boost is easy for you. To do it NA, I believe you can get close to 250 with the stock bottom end. Powerband you want though, different story. I can run simulations with the stock compression and see what its possible. 9.8:1 stock, add SI valves and shave a little off the heads should be closer to 10:1.

3500 will need the external crank trigger too.

How about this idea. 3400 block and bottom end, 3.4 iron head pistons, 3500 top end. Streetable with the right cam. Did I mention that you should give me a budget for 250whp:P

[geoffinbc]

Yea I guess what percentage of loss are you guys accounting for? Who tuned your computer Superdave?

[crytical point]

Well I live in FL and do not believe in emissions and remove all of them or disable them. Florida has no emission laws other than the federal law but I don't care about that one and I just cut the cat out. As for competence with cars, I have built a 10sec 3rd gen camaro with a 350 and junk yard parts with a little nitrous and I have a 78 monza that is my autoX car and it has a cosworth 4cyl that I built and I have ALOT of experience that I just don't have alot of room for but I can port, polish, grind, weld , and just about anything I need to do. When I swap I will be using OBD2 and will get it tuned but as for cam shaft for the 3500 what would I do about that because I can get a cams for 3400 but would they swap into a 3500? What would I get as far as compression using 3500 heads on a 3400 with the iron 3.4 pistons because I know the aluminum heads on a 3.4 will get a really high compression and I would love to have 10:1 and 11:1 would be streching it on 93 octane. Also I would like to say that after being on pennocks forum it is great to be on a board that understands these engines will not explode with more that 200hp but this is going into a fiero with a 4t60 and I don't want to break axles and not worry about the god awful rear slip that a 40front 60 rear weight distribution gives a awsome car for doughnuts but scary in the rain.

The Rx7 is a AWSOME car and the engines put down awsome power with two power strokes. My girlfriends car is not stock since I made a race header, ported the intake manifold, removed emissions, jet the carb, and tuned. Now if I did all of that to another engine I would get alot of power but her car gained almost 60hp and 35tq and that puts it at 157hp and 122tq at 6800rpm. for christmas I have a ported and polished engine with a performance intake and holley carb and that will put this little 1.2L engine will put about 260hp and 200-220tq to the wheels at around 9000rpm.

ohh yea and budget is not a big factor because I do 90% of my own work and the other 10% I have a awsome machinist and I will build the engine piece by piece over a couple months because my 2.8 is slow but not going to give up any time soon. Sorry for this being long but I just get carried away with cars and performance.

[SappySE107]

The 3400 and 3500 use the same cams so no problems there.

[ForcedFirebird]

Where in Fl are you? I'm in greater FT Lauderdale area

I'm currently building a 3.4/3500 hybrid that will use 3.4 pistons. Bolting stock 3500 heads with 3500 gaskets will give you 11.5:1.

I also have a 3rdgen, but mine is driven by 60*'s

[Superdave]

Yea I guess what percentage of loss are you guys accounting for? Who tuned your computer Superdave?

15% loss in a HM282

Moonwell and I.. still needs alot of fine tuning.


It's stored for the winter now, next spring i'll pull it out and play with it more...

[ForcedFirebird]

15% loss in a HM282

Moonwell and I.. still needs alot of fine tuning.


It's stored for the winter now, next spring i'll pull it out and play with it more...

Ahhh, winter. It has been getting down into the 80's here finally - and the rain has stopped!

As far as RWHP, a 3400 top end on a 3.4 in an fbody was chassis dynoed at 191whp. It had a small cam and headers other than the top swap.

I like Ben's idea of using 3.4 pistons 11.5:1 SCR FTW.

[SappySE107]

Personally, id run the DOHC pistons. With 3500 heads its about 12.4:1 compression. I know it runs now...

[ForcedFirebird]

Personally, id run the DOHC pistons. With 3500 heads its about 12.4:1 compression. I know it runs now...

Has anybody gone that high on premium fuel with 3x00 heads? I think the OP wanted to use pump gas. Could always add a little xylene

[SappySE107]

It ran on pump gas and not tuned...for a little bit. I know 11.5 can run on midgrade so 12.4 and premium should be a good push on the limit.