Hoping to build a really nice MPFI Gen-1 V6/60

[82-T/A]

Hey guys,

Well, I have an 87 Fiero SE / V6. I'll be dropping in a 5-Speed manual (Getrag). I'm trying to decide what the proper build should be. Ideally, I'd really like to see high 14s in the quarter in my Fiero, but I would be satisfied with low 15s.

As I understand it, the 2.8 can be made to produce higher rpms (I think, correct me if I'm wrong, because of the longer stroke?), but of course, the 3.4 produces more torque obviously because it has more displacement.

The motor I have in there right now was kind of a hack job. I didn't know much about cars back then, so I rebuilt my 2.8 into a 3.1 using a "stroker kit" from ARI Racing. It dropped my compression to something like 8.5:1. I installed .030 overbore hyperutectic pistons which I assume upped the compression slightly, but still lower than the stock 8.9:1.

Now... when it comes to performance, I COULD just drop a 3800SC or a 4.9 in there, but I'm really a stock nut. To me, everything has to look 100% stock or original, so I'm sticking to the V6/60 GEN-1 block. Plus, I also really REALLY like the sound it produces. With all of that in mind though, I'm stuck having to live with the pretty red Fiero intake plenum, which as I understand it is pretty restrictive to anything over a stock HO 2.8.


I guess I'm looking for some advice. I want to know if I should try to build a high-revving 2.8, or build a beast 3.4 (or something in between). My goal is 200hp, wether that's at 7,000 rpms on the 2.8, or 5,500 rpms on the 3.4 doesn't really matter. I figure 200hp is reasonable for a built up 3.4 with the H272, and odds and ends.


With the restrictive intake that is the Fiero, what do you think my best solution would be?


Thanks!!!


Todd,
2006 Pontiac Solstice
2004 Volkswagen Beetle
2002 Ford Crown Victoria LX-P74
1987 Pontiac Fiero SE / V6 5-Speed
1984 Porsche 944
1981 Pontiac Trans Am WS6
1973 Volkswagen Type-2 Transporter

[bjornmk1]

no way you're going to get 200hp out of a 3.4 with that intake.
no matter what cam or other stuff.

if it has to look stock you could have darrel morse extrude hone
you intake and get a larger throttle(also d.m.) that should be good
for a few HP but you're not getting 200hp without forced induction
on that intake NMW.

just my 2cts.

[82-T/A]

no way you're going to get 200hp out of a 3.4 with that intake.
no matter what cam or other stuff.

if it has to look stock you could have darrel morse extrude hone
you intake and get a larger throttle(also d.m.) that should be good
for a few HP but you're not getting 200hp without forced induction
on that intake NMW.

just my 2cts.

Thanks for the response. I do already have the ported throttle body and matched intake plenum from Darrel Morse. The way I see it though, nothing's impossible, it's just a mindset!

The 3.4 in the Camaro / Firebird isn't that much more free-flowing, is it? Doesn't that motor put out about 170hp? I'm only looking for 30 more horsepower (not rear-wheel horsepower).

What other options do I have for the plenum in terms of porting.

I've had thoughts of sending the entire thing to an extrude-hone shop and have them push that sludge through my entire intake tract.

[Superdave]

you'll spend TONS of money trying to get that kind of power out of that engine... it's just not going to happen w/o tons of custom parts.. then it won't look stock any more.

Best bang for your buck, a gen3 3400 SFI engine. bolt that in with a Jbody engine harness and '7730 ECM. guaranteed 190 WHP / 200+ tq bone stock with the right chip.

[82-T/A]

you'll spend TONS of money trying to get that kind of power out of that engine... it's just not going to happen w/o tons of custom parts.. then it won't look stock any more.

Best bang for your buck, a gen3 3400 SFI engine. bolt that in with a Jbody engine harness and '7730 ECM. guaranteed 190 WHP / 200+ tq bone stock with the right chip.

Thanks Dave,

I won't say that money is no object, but it absolutely must look stock. Is 3.4 absolutely the way to go? Or would I be better off building a high-revving 2.8?

CAN I produce those numbers if I spent upwards of $1,000 bucks on extrude-honing?

This was my first car, so it's my goal to pretty much keep it forever. I'm past the point of doing all the crazy mods, cold air intakes and all that other stuff, and I just want to make it perform well, but look stock. If at the very least, I'd like to get as close to 200 as I can (naturally aspirated and looking stock).

[El_Diablo]

why not go with a small port 3400SFI? that upper manifold looks kind of like it belongs in older cars and you could always get some decent numbers with the right P&P job, maybe a cam and higher compression aswell?

[Superdave]

Thanks Dave,

I won't say that money is no object, but it absolutely must look stock. Is 3.4 absolutely the way to go? Or would I be better off building a high-revving 2.8?

CAN I produce those numbers if I spent upwards of $1,000 bucks on extrude-honing?

This was my first car, so it's my goal to pretty much keep it forever. I'm past the point of doing all the crazy mods, cold air intakes and all that other stuff, and I just want to make it perform well, but look stock. If at the very least, I'd like to get as close to 200 as I can (naturally aspirated and looking stock).

I suppose you could grab a Camaro 3.4, slide in a H260 or H272 cam. Port the crap out of the heads and top end.. maybe some DOHC 3.4 pistons to up the SCR, then find some headers, larger TB and bigger injectors. it would perform nicely, might get you close to 180 crank HP but others on here have done all the same work to the iron head engines with lesser results.

extrude honing will help but i don't think you could port an iron top end to flow close to the gen3 stuff... they weren't built with the thought of anyone wanting to get 200 HP out of them all motor...


If you really want to keep it looking stock, i bet you could tuck a small T25 turbo in the bay somewhere and run like 8 PSI on the 2.8 with a H260 cam. that could put you close your 200 HP goal easy.


check out this site: http://www.turboz24.com/

he's using a 3.4 iron top end on a 3.1 FWD with boost making 400+ HP.

[82-T/A]

If you really want to keep it looking stock, i bet you could tuck a small T25 turbo in the bay somewhere and run like 8 PSI on the 2.8 with a H260 cam. that could put you close your 200 HP goal easy.

check out this site: http://www.turboz24.com/

he's using a 3.4 iron top end on a 3.1 FWD with boost making 400+ HP.

Thanks for the advice. My first goal really is to keep it stock, and then try to get the most power out of it as I can. Do you have links to some similar builds that people have made using the Gen-1 block?

Like I said, speed isn't overly a huge concern, I just figure the easiest way for me to get there is to do so with 200hp. But like I said, I want to be able to break into the 14s. But... if low 15s is all I can muster, I'm happy with that.

[34blazer]

i spent $1100 on my ironheads and they didnt even come close to the flow #'s of the gen3 heads (stock). the peak on the intake was 170cfm@.480 up from 130cfm. ill sell you my irons, they are already clearanced for higher lift cams

[ezrollin]

You can get 200 hp out of a 3.4 w / ironheads but I'm not sure if using a stock mpfi intake.Someone flowed a [mpfi] but can't remember the numbers. A 3.4 w / mpfi is rated 160 hp, a set of pocketedported heads will net you about 85 % of the power that's available and you can do it yourself,with a 272 cam you would see 180-185 hp.Don't know if the mpfi would be a restriction,the 200 hp one had a carb.

[34blazer]

http://www.trueleo.com/intake1.htm

[IsaacHayes]

That intake won't keep it looking stock... That's what you see first. And that intake isn't that great either.

It's just not really possible to do what you're asking. Something has to give. Either speed or looks..

A huge ass cam, 3.4 block, super high compression, ported everything, and headers might do it. But it may not drive very nice...

[34blazer]

trueleo flowed the stock intake. thats mainly why i posted the link

[ezrollin]

I did some research and found a guy that flowed a 2.8 intake,stock and ported. Stock was 418 and ported was 432 cfm,of course this could vary depending on how good the porting job. If a 3.4 flows 326 cfm @ 6500 rpms when does the intake become a restriction. Also, you can build a manifold with ports and runners to big which will reduce velocity and performance.

[sharkey]

the fiero intake is a huge restriction, no 2 ways about it. the plenum is too small and the runners have way to may restrictive bends and small runners. this intake was designed to increase torque (wich it does) however it does it at the expense of horsepower, typically a stock motor wont pull about 5000rpm, the more mods you have the worse it gets. yes you can build an intake too big, but thats were the research and design comes in. there are formulas to design an intake for your application.

as for 200hp, i think you will fall very short. i did a pretty decent build :
-86 2.8l
-probe industried forged 9.5:1 pistons
-beam polished conecting rods, arp rod bolts
-clevite bearings
-mellings high volume oil pump
-comp cams 260h2 cam
-comp valve springs, locks, retainers, and timing set
-SI stainless valves
-86 high output heads, ported
-ported fiero intake
-19lb injectors
-60mm throttle body
-megasquirt II engine managment
-custom headers
-full dual exaust with 2 vibrant 3 way mini cats and 2 flowbaster 60 series mufflers

my car still runs 15.4s with no traction issues. it pulls to about 4500 and falls on its face. i ran a best of 86mph, other cars running around that time were around 90mph or higher. and when i say ported heads, my dad has done race porting for years and spent over 20 hours on the heads alone. id guess i have about 160hp max.

if you really want to keep that intake, id suggest building a 3.4l with 10-10.5:1 compression and if you dont mind working on it, a solid roller cam. id also have some serious porting done on the heads, have the manifolds extrude honed, and at least a 60mm throttle body (i use a jeep 4.0l tb with a custom adaptor). it wont be very fun to drive with a huge solid cam, you can go smaller but you will miss your goal. my only other thoughts are to build it with forged pistons and stainless valves and throw a 100 shot of nitrous on it, that would deffinitly give you your 14 second pass you want.