well, I thought I would give an update so as not to let my thread die, not like I have done too much since I last posted, although I have drawn up a template for the tranny adapter, which from the looks of it should work great, in a few weeks I'll take it to a machine shop and have it cut(though maybe I will make it a cad file first so they can just CNC it) also in a few weeks the engine is going to the machine shop to be bored from 3.0L to 3.2L(as far as engine work goes I am converting to a 3.2L setup, SHO engines had a 3.2 for the auto trannies for additional torque and 93-up 3.0 engines have enough cylinder wall to convert, which is how the factory converted from 3.0 to 3.2...they just bored it out) I'll just have the engine bored out, and cleaned, thats about it, I'll be using the stock rods(good to 600+HP) and my custom 10.5:1 wiseco forged pistons(nice shiny flat top pistons, which cost me $150 a pop, not exactly cheap) as far as the rest of the engine build goes, it will all be stock parts, the only performance part I'll be using are the pistons since the rest of the engine is capable of plenty of power, though I may go with some camshafts at a future date, but they are $700, more than I can stomach just now. I have also settled on the turbos I will be using, I have decided on Mitsubishi 14bs from a 1st gen eclipse, good for up to 300HP each, but still small enough to spool quickly on a 3.2, they will again go on at a later point though since I will be breaking the engine in NA, I have decided to take some advice you guys give and drop my street boost down to 7psi, which should give me roughly 330HP or so, 10psi race(360hp or so) to start with anyway, I will constantly be datalogging EGTs, wideband AFRs, cylinder head temps, oil and water temperature and if it looks safe I will be increasing boost, I am also considering running alcohol or water injection to cool things down further in addition to I/C and CO2 cooling to cool I/C further, if I can cool my intake temps to 80 degrees and combustion chamber temps as well I wont be as worried about slightly higher boost, again though, this engine will never see more than 15psi under any circumstance(another reason I chose these turbos, since 7-15psi is their best operating range)

So whats new man I have a connection with a 3.2 SHo engine but I want to see how yours works out first.

just curious, if your starting a build thread, why are there no pictures?

personally i LOVE the look of those yamaha engines, but i always wanted one of the 3.4L v8 ones, but ill take mine with the cam gears already pinned or welded please!

matthew

quote Originally posted by wicked93gs: I think your right about the fact that the car being heavier will stress the tranny more(my neon weighs in at 2200lbs curb weight) But I hope to do enough weight reduction on the fiero to minimize the difference(fiberglass or CF hood skin, removal of all PS and A/C stuff, back glass replacement by lexan,whatever other possible weight reduction I can think of)

Uh, just so you know...you don't have to remove the PS...(hehe) Just messin' with ya...how's it coming?

quote Originally posted by Marvin McInnis: 10.5:1 CR + 10 psi boost + "street gas" = Seriously ... I'm not trying to discourage you, but you do need a reality check.

tahst apointless argument.. that can happen on 8:1 compression pistons too... i look at it this way.. if the Honda K20a engines, out of the rsx type s and type r acuras, whcih are 11.5:1 compression.. can handle 9+ psi boost from a jackson supercharger, then ths guy can manage

edit: I missed where you said you decided to run 7psi, so ignore what I said there -- sorry

A few things.

A "full standalone" engine management won't completely prevent detonation. You can throw as much fuel at the engine as you want, but you'll have to retard the timing so much that you would have made more power with lower compression (and you lose the response that you want to keep). I know that you have already had the pistons sent to the machine shop, so you can't drop the compression now, but you should probably consider running less boost on pump gas with that compression. I'm not saying 10psi on street gas with 10.5:1 compression isn't possible, but if you are worried about durability (which you seem to be), then I would suggest using race gas for 10psi, as well as some methanol, and a nice intercooler.

Also, it sounds like you are planning to use an air to air intercooler in the trunk. The scoop on the decklid won't get much air to go over the intercooler. The Fiero has a low pressure zone over the decklid, which is why the stock wing isn't functional and why a vent on the decklid (rather than a scoop) works so well. I would use a water to air intercooler, with a nice heat exchanger in front of the radiator. Since you are getting rid of your A/C, you can put the exchanger where the condesor used to be.

I want to see this project finished. I would love to build an SHO V6 someday -- I think the engine seems to be very well engineered. I also think that high compression on a turbo motor is completely overrated. I am running 8.5:1 compression, and off boost, my engine is still very strong. Look online for something that approximates horsepower loss due to compression changes, and you'll see that two points of compression or so doesn't make a big difference in power.

Finally, I think that a single turbo will serve you better in terms of packaging and turbo lag. Remember, two turbos means twice the rotational drag of the turbos. Also, Corky Bell's book is a good read for basic information, but it's filled with a lot of opnion that people take as gospel.

Good luck with your project.

--Bryson

[This message has been edited by bryson (edited 07-07-2005).]

Dont know if this was mentioned before but the SHO V6 was originally designed for Ford "Fiero Fighter." The Ford mid-engined car got cancelled shortly before it saw the light of day (late 1987). Ford had already signed an agreement with Yamaha to build thousands of engines, so they had to find something to put this engine in. When I worked at the Ford Florida Eval Center I had an 89 SHO (awesome car). The lead engineer for the SHO program showed me a bunch of pictures of cars that were being tested with the SHO engine. Merkur XR4ti, Ranger, Windstar, Aerostar, Mustang and Taurus were all candidates. The plan was just to use up the engines they had paid for, but the SHO proved so succesful (it out performed every sedan in the US less than $50,000) that it kept itself going. It became successful enough that GM took notice and built their own SHO fighters, the 3.4TDC cars. Funny how what goes around, comes around.

Brett

LoL True though! It seems GM wanted a DOHC so bad they told there engineers to slap some DOHC heads on a 3.1 and punch it out for alittle more kick! (perhaps not literally, but thats what it seems) But, alwas keep in mind that the 3.4 DOHC (3200 TDC at that time) was put into the 90 prototype, witch was created in 1986 IIRC... So they must have seen it coming well in advanced. It still amazes me how far ahead of the market the car companies REALLY are... usually 4-5 years. And its always there goal to suprise the competition, at the same time build interest in it before it comes out. A balancing act of sorts. Even still the motor is a freak, I like the 3.4 DOHC. But I suppose Iv'e gotten off the topic at hand... the SHO.

Ever seen a SHOgun? I saw one of the seven made at a car show on Long Island. That was one cool little car, fast too.

quote Originally posted by Fierobsessed: LoL True though! It seems GM wanted a DOHC so bad they told there engineers to slap some DOHC heads on a 3.1 and punch it out for alittle more kick! (perhaps not literally, but thats what it seems)

Thats essentially the SHO engine. It's a 3.0L "Vulcan" pushrod block. The bottom end was modified a lot, but its roots are in a pushrod motor.

Brett

Trying to reduce the weight of a Fiero is an exercise in futility. It's already skinned with plastic and the back glass acts as part of the frame. I've read post of 2000 pound Fieros but I'd have to see the weight slips to believe it. When I built my trike I was amazed to find that it weighed in at 1750, only 750 pounds less than my 87 GT.

this is prolly a little late, but i wanted to get it out about the compression ratio. I have a fwd 3800 from a 91 olds in my s-10. !'m running 17 psi with stock compression and cast pistons managed by a sds and i have yet to melt a piston. case and point its all in the tuning

Well you have the heads off open up the combustion chambers a bit to knock down the compression. Also if you plan to replace the valves opt for... i think they are called tuiped versions .... the ones with the circular relievs in the bottom... they are lighter and will lower your compression a bit too. Just a sugestion.

No amount of tuning will prevent detanation at that high of boost and compression. And you mentioned innefficient intercoolers, well, frankly, you can use the best intercooler in the world and chances are its going to suck in a Fiero, that's just how the Fiero is. You should consider air/water, as there isn't very many places to find air/air in a good, dependable, and sightly manner.

It is the same thing N/A, the best overall compression ratio for a standard, 4 valve central plug head, is 11.2:1. Yet people can't stop saying how more compression=more power. It simply isn't so. With the type of management you are running on the aforementioned N/A motor, I'd say 12:1 would be max. Any more than this, and you have to pull timing SOOOO much that you end up loosing power. Sometimes it is better to have timing that compression. These numbers are confirmed by "Four Stroke Performance Tuning," by A. Graham Bell.

But from reading, it seems evident that you know more than a man who has been building forced induction and naturally aspirated Cosworth racing engines for almost 45 years.

Good luck, it is definately a unique and sweet engine swap, and I can't wait to see it further along, but I'd seriously reconsider your numbers. Also, if you are only looking for 300-350hp, why are you using a fuel management system that is going to be well into the thousands, made to control 600-1200hp? The stock SHO ECU, tuned for boost ($200), is capable of 500hp, reliably! Not at 10.5 compression it isn't, but as I said above, that much compression is doing more harm than good. You will make more horsepower, more low end torque, better drivability, at a much cheaper cost, with a stock ECU tuned for boost, 8.5-9.0:1 pistons, and a single compressor. Just my opinion though...

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"Item might be dangerous and cause death, do not use in a real car."
"Proper capitalization is the difference between helping your Uncle Jack off a horse and helping your uncle jack off a horse."

quote Originally posted by triker: Trying to reduce the weight of a Fiero is an exercise in futility. It's already skinned with plastic and the back glass acts as part of the frame. I've read post of 2000 pound Fieros but I'd have to see the weight slips to believe it. When I built my trike I was amazed to find that it weighed in at 1750, only 750 pounds less than my 87 GT.

Our roadster weighed 2050 with V6 and 4 speed. Quad 4 or Ecotech should take it under 2000 Lbs. Probably close to the weight of a Lotus Elise. A couple pix of tje roadster can be found here: https://www.fiero.nl/forum/Archives/Archive-000002/HTML/20040710-1-037446-2.html

It was still licensed for the street after the top was removed, but clearly does not have enough windshield to avoid equipment (or more correctly, lack of equipment) violation.

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FierOmar

quote Originally posted by AaronZ34: No amount of tuning will prevent detanation at that high of boost and compression.

Tell that to Steve Saleen, whose S-281E uses 10.5:1 CR and 6 or 8 lbs boost-I don't remeber which, for around 500hp. Yes, it IS in the tuning...mostly.

Wicked, good for you. Good luck on this project. I'll be watching. And one day, just to irritate the narrow minded, I'm going to build a 351 powered Camaro and a 350 powered Mustang. (Hehe-a "Camarang and a Mustaro ). Then maybe a <gasp> VTEC Fiero...

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86 Fiero GT
-SBC, Eibach/Koni suspension, in prog...

04 Mustang Cobra
-Stock, for now

[This message has been edited by Hulk (edited 08-22-2005).]

My N* has 10.3-1 compression and runs on 87 octane. This is a 2000+ engine. I imagine I could run up to 8psi of intercooled boost with an efficient turbo and pump gas.

Its in the tuning, but it also has alot to do with the combustion chamber its self.