All excellent info. Hudini: ingenious using the stock expansion joints for your crossover I need to go "shopping" at the junkyards for crossover parts. Personally I will be looking at the bit too small for a 3.4 T3 turbo as 4-5 PSI is exactly what I want. I want low boost that only gives the engine a little kick in the pants, 200HP on a 3.4 with a small turbo would be very nice. more would be better but I'm not greedy, I do not want to venture into the land of intercoolers.

Although that is a good topic. Intercoolers, even for low boost are a benefit right? at what point do they become a must have? Where can you stuff one? will even a tiny intercooler you shove down in the engine compartment by the cat give you a benefit?

Most turbo kits don't even have a intercooler included (Design1 kit for example) what is your take on them? Also since the intercooler is a part of the intakes, any benefits there? straight is better? are too many bends bad? what happens if you don't listen to to others and don't put in the blow off valve or it's set wrong? where can you put it? how do you keep your vac lines from popping off during boost?

[This message has been edited by timgray (edited 08-19-2007).]

Ok let me say this straight up, I am not a turbo expert, and am not claiming to be anything more than a shade tree mechanic. However when I was researching turbo info for my 2.8 many years ago, well before domestic cars and boost became a mod of choice, I wrote this article. I never ended up going further with it, because I chose to toss the V6 and slap in a bigger motor. I may still do the turbo however it will be boosted on my V8 rather than my V6.

http://captfiero.com/turbo.htm


Its a kinda Introduction to Turbo's for Fieros for Dummies. Nothing to high tech, just basic info in an easy to read and understand format.

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85GT 5spd ,93 Eldorado 4.9 Dual O2 Custom Chip, Archie Clutch. Custom Exhaust. MSD Everything 245/50/16's Not Your Average 4.9 Capt Fiero Com --- My Over View Cadero Pics Yellow 88GT 5spd Stock.

quote Originally posted by timgray: Intercoolers, even for low boost are a benefit right?

Yes, but like anything else it seems, intercoolers have advantages and disadvantages. The former center around (not surprisingly) their cooling ability.

An intercooler increases power potential by lowering the temperature of the incoming air to the engine, and it also helps reduce the possibility for detonation.

However, an intercooler also increases turbo lag, and the bigger it is and the farther away it is from the engine's intake, the more it increases turbo lag because it takes more time for the turbo to push the intake air through the additional plumbing required to get to the engine.

Also, for a Fiero, finding space for an intercooler that is nearby the engine's intake --- but without putting it in the trunk --- can be a challenge.

Probably an even bigger challenge is figuring out exactly how to quantify the aforementioned tradeoffs, as I would think those tradeoffs would be dependent upon both the engine's components (e.g., the engine's compression ratio) and the personal preferences of its driver (e.g., one's tolerance for turbo lag).

I can't take credit for the expansion joints. Joseph Upson showed me the error of my ways. When I asked him about intercoolers he mentioned 10psi as the point where a car would benefit from one. This is also mentioned by Capt Fiero in his article. There are several air/water units that could be used in our tight engine compartments. The air/air ones would need really long plumbing to get the cooler out front.

Anyone else have any intercooler insights? Do's and don'ts maybe?

a small intercooler that may work well for the Fiero is the SMIC from the Silvia compact and good for 8 to 10 psi. The guys at NissanSilvia may be a good source for used turbos, SMIC, and loads of information as well

With the large side vents on some cars (Madcurl's and Troyboy's), is there any chance to fit an intercooler on the side and actually have it function correctly through the side vent?

Bob

PS, I love those big side vents that could suck in a Yugo...

When considering to Turbo, does one keep the EGR system or delete,

Emmision consideration is a must

Thanks

quote Originally posted by RCR: With the large side vents on some cars (Madcurl's and Troyboy's), is there any chance to fit an intercooler on the side and actually have it function correctly through the side vent? Bob PS, I love those big side vents that could suck in a Yugo...

that's why I recommended a side mount (SMIC) that ones expensive but you could pick up a used stock one off a Silvia prity cheep I don't think your standard front mount (FMIC) would work in the side panels very well in a fiero but with a custom deck lid a top mount (TMIC) would probably work fairly well

The first gen DSM intercoolers are a side mount and can be used in the Fiero's side panel area with a scoop. The big plus to using the 1st Gen DSM intercooler is that the DSM guys practical give them away. I have seen them from Free to around 20 bucks. They are about the size of a large shoe box. Not great if you plan 20psi boost, but low boost I would call them pretty practical.

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85GT 5spd ,93 Eldorado 4.9 Dual O2 Custom Chip, Archie Clutch. Custom Exhaust. MSD Everything 245/50/16's Not Your Average 4.9 Capt Fiero Com --- My Over View Cadero Pics Yellow 88GT 5spd Stock.

one little trick i use to secure all vaccuum lines is to secure them with small tie wraps .also dont forget to relocate stuff like egr valve outlet to a non boosted part of the intake .leave on all your polution control stuff .the gains are not worth taking it off for .

Did you use one way valves on any vacuum lines that only need vacuum?

I have a KKK K26 turbo in my car. This turbo came factory on many an Audi and Porsche of the mid-late 80's... Anyone familiar with it?

From what I've read it is comparable to the Garrett GT25. It does not have an built-in wastegate so you need one of those. How is yours setup?

[This message has been edited by Hudini (edited 08-21-2007).]

Covering all basics so far, we have a intake, exaust and turbo + wastegate covered. We cant just slap this on a car and see it go. Other than ECM tuning and changes and the 2 BAR (or higher) sensor, what else is really needed. I have read that stock injectors are good enough, more injector etc...

also what about the very controversial double head gasket trick? If I boost and lower my compression will I stay farther away from the dreaded detonation? at what Boost level do I have to start thinking about reducing compression? Fuel delivery, is an adjustable regulator a must? Also what about all the other parts that use the system vaccuum? will the car freak out because the vac system is no longer working? Brake assist cylinder is Vac operated, do you add a check valve?

Plugs reccomended? Colder I am assuming. what do you use?

I also forgot... boost controller, What is it and how do you choose the right one. BOV, how do you choose the right blow off valve. Is using a n old stock OEM BOV good enough or do you really need the billet aluminum bright purple $500.00 type from a high end racing shop?

[This message has been edited by timgray (edited 08-21-2007).]

I woudn't try using two head gaskets. Probably wouldn't seal and having the wrong quench (distance between the top of piston at TDC and flat portion of head) can be more detromental than haveing too high of compression. You wont need an adjustable fuel pressure regulator if you're already tuning the ecm. I'm pretty sure the brake vacuum resevoir already has a check valve on it.

EDIT. Use two head gaskets but only one per cylinder head

[This message has been edited by Zac88GT (edited 08-21-2007).]

quote Originally posted by Hudini: From what I've read it is comparable to the Garrett GT25. It does not have an built-in wastegate so you need one of those. How is yours setup?

It's not bad but I have 2 exhaust leaks and it smokes when cold. It has the external VW wastegate. I am looking to get a spare on ebay and then swap and get this one rebuilt... I was wondering if there were things like the T3/4 hybrid mods that could be done to it...

quote Originally posted by timgray: Covering all basics so far, we have a intake, exaust and turbo + wastegate covered. We cant just slap this on a car and see it go. Other than ECM tuning and changes and the 2 BAR (or higher) sensor, what else is really needed. I have read that stock injectors are good enough, more injector etc... also what about the very controversial double head gasket trick? If I boost and lower my compression will I stay farther away from the dreaded detonation? at what Boost level do I have to start thinking about reducing compression? Fuel delivery, is an adjustable regulator a must? Also what about all the other parts that use the system vaccuum? will the car freak out because the vac system is no longer working? Brake assist cylinder is Vac operated, do you add a check valve? Plugs reccomended? Colder I am assuming. what do you use? I also forgot... boost controller, What is it and how do you choose the right one. BOV, how do you choose the right blow off valve. Is using a n old stock OEM BOV good enough or do you really need the billet aluminum bright purple $500.00 type from a high end racing shop?

I went with 24lbs injectors and had Darth Fiero tune the ECM for it (7730 ECM). I went big to make sure there was enough fuel later on when I go to a bigger turbo plus I want to run E85. I think the OEM 3.1L turbo injectors were even bigger.

5-7psi should keep the detonation at bay with enough fuel programmed into the ECM and the injectors can handle it. Any more boost and you need to start thinking about lower compression, alcohol injection, intercooler, bigger injectors, etc. I added an adjustable regulator JIC. I asked Darth to tune for 42-43psi though.

Vacuum for the brakes is there when off the throttle (and on the brakes). You don't need vacuum to the brakes when you are trying to go fast! The power booster has a check valve right on it. It is that plastic thing that sticks into the booster. Not sure about cruise control since I don't have it. The 7730 uses digital cruise anyways. The PCV valve is already a one way valve. The MAP sensor needs to sense both vacuum and boost. The EGR solenoid probably needs a one-way valve but I deleted mine so not sure. The EVAP canister probably also needs a one-way valve.

The new iridium plugs are supposed to be very boost friendly. No white hot tip to cause detonation. My turbo Volvo has them OEM.

Don't need a boost controller with the T3. The internal wastegate will handle that. Boost controllers are for bigger turbos with external wastegates. The boost controller actuates the wastegate.

The Bosch BOV/Bypass valve is a good cheap alternative. I bought one of the type RS (made in china) generic knock offs. We will see how it works for $54.

Anyone else?

Ok, maybe I missed it somewhere among all the responses but....

I am interested in adding a turbo. I'm not looking to build a 300hp burner or take on 'Vettes at the lights. Just interested in a bit more 'kick in the seat' performance. To me that means low boost, maybe 5-7 psi.

Is it the general concences that a stock 2.8 and 5 speed can handle this without strenghening mods?

Will the computer adjust for this appropriately or is a replacement/additional ECU necessary.

Other mods like injectors should not be required with only a slight boost addition, right?

Thanks for your replies and congratulations on a great thread.

[This message has been edited by Copper85GT (edited 08-22-2007).]

quote Originally posted by timgray: what about the very controversial double head gasket trick?

Robert Wagoner, the author of "High Performance Fieros," reported on page 28 of his book that he was warned not to do that, but it worked fine for him. He later employed a steel spacer and one head gasket on each head to reduce compression to 7.5:1 compression for use with a bigger turbo, instead of his original 9.0:1, or the 8.2:1 he realized with two head gaskets per cylinder for use with a smaller turbo, or the 9.0:1 he had with the engine in normally aspirated form.

quote Originally posted by timgray: If I boost and lower my compression will I stay farther away from the dreaded detonation?

Assuming compression wasn't already much, much too high to begin with, I think the short answer is "Yes."

quote Originally posted by timgray: Fuel delivery, is an adjustable regulator a must?

I don't know if it's a "must," but I use one just because I like the flexibility it affords for tuning pruposes.

quote Originally posted by timgray: at what Boost level do I have to start thinking about reducing compression?

I've actually a similar question to yours. How much boost can a (daily driver) 3.4L engine safely handle without pushing it to the ragged edge? It won't be using water injection or an intercooler, and it currently has 9.2:1 compression because the cylinder heads have been shaved slightly. Under those circumstances, should one not even bother trying ANY boost with 9.2:1 compression, but first reduce that to say, 8.5:1 or less?

All I have to say is that boost is a funny thing… you get some, you are happy. But you always know that one or two more pounds add up to 15 to 20 more horse… and that’s how boosted motors blow… good luck guys!

quote Originally posted by Copper85GT: Ok, maybe I missed it somewhere among all the responses but.... I am interested in adding a turbo. I'm not looking to build a 300hp burner or take on 'Vettes at the lights. Just interested in a bit more 'kick in the seat' performance. To me that means low boost, maybe 5-7 psi. Is it the general concences that a stock 2.8 and 5 speed can handle this without strenghening mods? Will the computer adjust for this appropriately or is a replacement/additional ECU necessary. Other mods like injectors should not be required with only a slight boost addition, right? Thanks for your replies and congratulations on a great thread.

From my research I do believe 5-7 psi does not require any engine work. The ECM will need to be reprogrammed to handle boost as it is setup now for only vacuum and a 1 bar MAP sensor. For extra protection many have switched to the '85 ECM as it has provisions for a knock sensor input. I swapped to the 7730 ECM as it was used on the 3.1L turbo grand prix. Personally I would go with bigger injectors. They are not expensive and the added insurance of sufficient fuel at WOT without running 100% duty cycle or higher fuel pressure is worth it to me. Especially if you are not running a wideband O2 sensor.

[This message has been edited by Hudini (edited 08-24-2007).]

quote Originally posted by Copper85GT: Ok, maybe I missed it somewhere among all the responses but.... I am interested in adding a turbo. I'm not looking to build a 300hp burner or take on 'Vettes at the lights. Just interested in a bit more 'kick in the seat' performance. To me that means low boost, maybe 5-7 psi. Is it the general concences that a stock 2.8 and 5 speed can handle this without strenghening mods? Will the computer adjust for this appropriately or is a replacement/additional ECU necessary. Other mods like injectors should not be required with only a slight boost addition, right? Thanks for your replies and congratulations on a great thread.

My setup uses a separate computer from the Grand National that just takes readings from a knock sensor and retards the timing. It's simple but it works.

On to the ECM. can you boost with a stock ECM other than the 85? is the only advantage of the 85 ECM the knock sensor input and capability? Other ECM's what choice is as easy and what is the benefit from using a newer ECM on a turbo build?

Other than buying your chip, what is the best place to start for tuning? I assume that you cant get a magical "add-a-turbo" chip from someone and it will work in all cars so a custom chip for your build up will be needed. For the low boost example would you need radical changes to the fuel and spark maps? anyone have any examples they would like to share?

I believe the answer is yes, you can use other year ECMs and yes, the knock sensor is the benefit of the '85. The benefits of the newer ECMs are faster processing speeds and more cells in the tuning table. (something like 8x8 cells versus 12x12 cells or more) Plus you can use a knock sensor and DIS if you go with the 3.4L pushrod engine. And the output of the ECM for tuning or datalogging software is 8192 baud versus 160 baud.

ECM tuning is magic to me. I just filled out a sheet with questions and Darth Fiero burnt me a chip. It is pretty close. I'll make some datalogs and send him the info for tweaking later. My plan is to drive to Ft Wayne on the way to Detroit and have the car tuned in person. Someone probably has the information you are asking about though.

My setup uses a stock 87 ECM with a separate buick controller that just takes in knock sensor input and retards the timing.

quote Originally posted by lou_dias: My setup uses a stock 87 ECM with a separate buick controller that just takes in knock sensor input and retards the timing.

any details on the buick controller? what car it came out of, etc...?

quote Originally posted by timgray: any details on the buick controller? what car it came out of, etc...?

Probably the early Grand National and Regal T-Type. I think in '87 they switched to a different setup.

It's only got 5 wires going in/out of it. There is a pic in the link I posted a few posts ago.

This link is to a recently purchased 1990 3.1L turbo Grand Prix: https://www.fiero.nl/forum/Forum2/HTML/085529.html

The turbo is a Garrett GT25. So add that turbo to your list of ones that work for the 60* V6 engines.

EDIT: Does the GT25 equate to 2.5 versus the T3? As in it's slightly smaller?

Note the crossover. That would make a sweet pre-made turbo crossover for an auto trans car. Especially if you mated the engine to the stock 4t60 4-speed auto trans.

[This message has been edited by Hudini (edited 08-26-2007).]

I found an old book on turbochargers that is incredibly full of info and details.

HPBooks Turbochargers by Hugh MacInnes ISBN 0-89586-135-6

It's old written in 1984 but it covers some of the details that rounds out all the info in this thread very VERY well. Outside the ECM tuning, I am convinced I can do a turbo project after the 3.4 install easily. and after talking to you guys a low boost 5-6 PSI boost would be inexpensive with the right parts.

Now to get the ECM tuning magic understood.

The aftermarket version of a boost timing controller is the MSD-8762. Summit has one for $228 on e-bay motors.

"If you run a blower, turbo, or even a naturally aspirated engine, MSD's Boost Timing Masters allow you to run at the edge of detonation for maximum power output. They can prevent detonation by automatically retarding the timing as your manifold pressure increases. The secret lies in a boost pressure sensor that's inside MSD's solid-state control box. The sensor reads boost pressure through a 1/8 in. vacuum hose attached to a boost pressure source. The result gives you peak power without harmful detonation. A dash-mounted control knob allows you to dial in the retard from 1 to 3 degrees per pound of boost pressure, up to a maximum retard of 15 degrees. Vacuum tubing is not included. These units are available for vehicles both with and without an MSD ignition."

In reality you could simply run a Boost Referenced Rising-Rate Fuel Management Unit and a Boost Timing Controller with no other changes. This was actually my first plan of action. Since the 7730 and a chip plus bigger injectors were less expensive and more accurate, I went that route.

Although I'm sure that MSD unit works, it sure doesn't sound like the right way to do it. It sounds like a 2-bar map sensor connected to a timing retard circuit. It has nothing to do with using knock sensor to retard the timing. By the time the user starts to "detect" knock, the motor could be fragged.

Bob

That timing box sounds like all it does is adds the boost spark map to the ECM without having to reprogram the ECM. That can be very useful! It's a part that would allow someone to add a Boost spark changes to a stock ECM without tuning. Add the Buick Knock sensor to that box, plus an adjustable fuel regulator and you would have enough to set the car up for boost without tuning the chip. Cool find! I am certain it would not be as perfect as a true tuned ECM setup but it would be a safe boost application.

My biggest question is that does the Fiero ECM detect any of the timing that the engine currently has or does it simply tell the Ignition module to retard timing? I am wondering if the ECM will flip out of it detects that the timing retard that is happening is not what it is calling for, or is the ECM dumb and is assuming the ignition will do what it is told?


One more question about Turbo oiling, What size of a lines are you guys using? also did you relocate your oil pressure sending unit to near the turbo or did you leave it where it was?

For oiling I am using -4 AN for the feed and -8 AN for the return. I extended the oil sender out a couple inches (non a/c car) with a brass pipe with a T on the end. Those with a/c would have an easier connection as the sender is on the front of the engine.

While a separate knock retard, timing retard, and FMU would work, it is the most expensive option. Simply switching to the 7730 ECM you get all the same benefits for less than $100.

Quick question on turbo choice. I have been looking at turbo maps all night. the 3.4 pushrod has 208cu/inch displacement. at 3000rpm it draws in 20 lb of air per minute. I am trying to achieve a 6psi boost.

I am looking at turbo maps and the T3-60 trim turbo that I assume is the turbo in the Thunderbird looks to piddle out of air efficiency at 6psi above 3000 rpm, yet if I boost my target PSI to 15 it works fine up to 4000 rpm. Am I reading these right? because that suggests I should look at a smaller turbo for my 6psi boost application. I want a 1.41BAR boost to cover from 3000 rpm to 5500 rpm.
Do I need to look at a different turbine blade then?

staying with the T3 housing will make life easier in the engine bay, the T4 is a monster.


As for the Upgrade to better ECM, I cant agree more, but I think more people would be willing to add a buick ECM module and knock sensor to an existing ECM. If we can make the whole idea as a super simple turbo design, just add these things, do this and then get ECM tuned.

I personally will probably upgrade to the new ECM like you did, I think my 3.4 will benefit from it and make my life easier.

[This message has been edited by timgray (edited 08-28-2007).]

The T3 is known to spool quick but run out of air at 5-7psi. The T3/T4 Hybrid though would run 5-7psi right on up to redline. You just get an adjustable wastegate actuator rod and set it to open at 6 psi (or an external wastegate and boost controller though more $$$). If you go smaller the turbo does even worse than the T3 and gives you even less boost at higher RPMs (but spools very quickly).

So basically a T3 turbo with a T4 exaust side on it to keep it from spooling up as fast right? Hmm, I'll have to start searching to see what cars came stock with such an animal so I can go looking in the junkyards. I hate dropping a grand on a new turbo when a used one + rebuild kit is far FAR more adffordable.

The T3/T4 Hybrid is the T3 exhaust side for a quick spool but a T4 compressor side for more air flow. I don't think any car actually came with this setup. For a starter turbo, the junkyard T3 is ok for me. Then when funds allow, upgrade to the T3/T4. They run about $250 on e-bay motors depending on which options you want.

I asked Joseph Upson from his 3900 swap thread which (2) turbos he is using. His reply:

T3 Turbos .60 compressor, .63 turbines, found on 80s Mustangs and Thunderbirds.
38mm Tial knock off wastegates with 8 psi springs, and ecm controlled boost solenoid for higher boost.

The K27 seems pretty equivalent to a T4 and my K26 seems close to a T3/4... The K26 is in alot of old volvos, audis and porsches. I picked on up on ebay for < $200 to replace the one I have installed that smokes when cold. I will probably rebuild that one and keep as a spare or put on ebay...

The K26 can make 250hp easy and some claim to 350 on a modded & tuned motor. It can do 14psi.

A useful link: http://www.80tq.com/turbo.html
More juicy info on K26 upgrades: http://www.clarks-garage.co...op-manual/eng-19.htm
http://www.geocities.com/jpeltopuro/pictures.html

So it seems the K26 is highly upgradeable... Bore out the housing to use the K27 compressor wheel and use the K26-8 hot side and you have 500hp.
The compressor wheel is a "993".

[This message has been edited by lou_dias (edited 08-30-2007).]