Pennock's Fiero Forum
  Technical Discussion & Questions
  The White Bug (Page 4)

Post New Topic  Post A Reply
Email This Page to Someone! | Printable Version

This topic is 4 pages long:  1   2   3   4 
Previous Page | Next Page
next newest topic | next oldest topic
The White Bug by pmbrunelle
Started on: 01-03-2019 10:14 AM
Replies: 139 (3923 views)
Last post by: pmbrunelle on 05-26-2020 12:13 PM
wftb
Member
Posts: 3593
From: kincardine,ontario,canada
Registered: Jun 2005


Feedback score: (4)
Leave feedback

Rate this member

Report this Post05-11-2020 01:30 PM Click Here to See the Profile for wftbClick Here to Email wftbSend a Private Message to wftbEdit/Delete MessageReply w/QuoteDirect Link to This Post
Use a bigger exhaust pipe and get rid of the muffler. You need more total flow capacity, even if you do everything on your list the 2.5" pipe is still a choke point. I use 2.5" piping on my engine and if I had room I would go bigger. I have a Solstice OEM cat converter and no muffler. Only loud when you build the boost up high, rest of the time it is fairly quiet.

------------------
86 GT built 2.2 ecotec turbo
rear SLA suspension
QA1 coilovers on tube arms

IP: Logged
La fiera
Member
Posts: 1519
From: Mooresville, NC
Registered: Jun 2008


Feedback score:    (7)
Leave feedback

Rate this member

Report this Post05-11-2020 02:27 PM Click Here to See the Profile for La fieraSend a Private Message to La fieraEdit/Delete MessageReply w/QuoteDirect Link to This Post
I think you'll need an external wastegate.
IP: Logged
ericjon262
Member
Posts: 2653
From: everywhere.
Registered: Jan 2010


Feedback score:    (10)
Leave feedback





Total ratings: 62
Rate this member

Report this Post05-11-2020 02:40 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
idea:

the inlet and outlet of your muffler are inline, weld a V band to the inlet and outlet, and in between porting the housing, and installing the larger housing, take an intermediate step of installing a straight pipe. if boost control is improved, it tells you your muffler/exhaust is too restrictive, if it isn't improved, you can re install your muffler, and have an alternate exhaust for track days that is an easy bolt in install.
My thoughts:

if the exhaust is too restrictive, it will drastically reduce turbine and WG efficiency, because the pressure drop across the two components is reduced. reducing pressure downstream of the turbine will make boost control easier and more consistent, as well as reduce "spool" time. while straight through mufflers appear to be very free flowing, some actually choke down engines quite considerably.

------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

cognita semper

http://www.fiero.nl/forum/Forum2/HTML/119122.html

IP: Logged
pmbrunelle
Member
Posts: 3323
From: Grand-Mère, Québec
Registered: Sep 2008


Feedback score: N/A
Leave feedback





Total ratings: 54
Rate this member

Report this Post05-12-2020 08:44 AM Click Here to See the Profile for pmbrunelleClick Here to Email pmbrunelleSend a Private Message to pmbrunelleEdit/Delete MessageReply w/QuoteDirect Link to This Post
Considering my main problem now is that the turbine is generating too much shaft power, I don't think that unrestricting the turbine's exit will help it generate less power.

However, the wastegate would do a better job of stealing flow away from the turbine if it dumped to a short non-restrictive exhaust, such as a screamer pipe.

This is what the wastegate passage looks like for exhaust gas entering the inlet flange:


I think that this Saturday I will go to Princess Auto and purchase an electric die grinder + burrs. I need something more powerful than my Dremel to port this.

Even if porting the wastegate passage doesn't solve my immediate problem, the electric die grinder will be a useful tool to have. I don't have a big enough air compressor to run an air-powered die grinder.

[This message has been edited by pmbrunelle (edited 05-12-2020).]

IP: Logged
Will
Member
Posts: 13241
From: Where you least expect me
Registered: Jun 2000


Feedback score: (1)
Leave feedback





Total ratings: 234
Rate this member

Report this Post05-12-2020 09:46 AM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
If you could add as much radius as possible on the near edge while keeping the far edge sharp, that would help. Not sure if porting the wastegate port can get you where you need to go, but it's worth a shot.
IP: Logged
claude dalpe
Member
Posts: 82
From: montreal,quebec,canada
Registered: Feb 2009


Feedback score: (1)
Leave feedback

Rate this member

Report this Post05-12-2020 12:23 PM Click Here to See the Profile for claude dalpeClick Here to Email claude dalpeSend a Private Message to claude dalpeEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by La fiera:

I think you'll need an external wastegate.



Your wastegate comes out in your restrictive exhaust which prevents it from operating at full capacity!
IP: Logged
pmbrunelle
Member
Posts: 3323
From: Grand-Mère, Québec
Registered: Sep 2008


Feedback score: N/A
Leave feedback





Total ratings: 54
Rate this member

Report this Post05-17-2020 08:38 PM Click Here to See the Profile for pmbrunelleClick Here to Email pmbrunelleSend a Private Message to pmbrunelleEdit/Delete MessageReply w/QuoteDirect Link to This Post
I ported the wastegate passage. There is a radius of about 0.4 inches on the inside of the turn. I left a sharp edge on the far side.


Looking into the wastegate hole towards the inlet flange, with a light shining into the inlet flange:


The shape of the turbine housing lent itself to me carving a scoop shape to help divert exhaust gas towards the wastegate passage.

2nd gear pull from 905 RPM to 6131 RPM, followed by a 3rd gear pull:


During WOT, manifold pressure stabilises at about 155 kPa.

To see what would happen without engine acceleration, I brake boosted the car on the highway for a few seconds. Manifold pressure remained stable. I noticed that stock 84-87 brakes heat up quickly!

[This message has been edited by pmbrunelle (edited 05-17-2020).]

IP: Logged
La fiera
Member
Posts: 1519
From: Mooresville, NC
Registered: Jun 2008


Feedback score:    (7)
Leave feedback

Rate this member

Report this Post05-17-2020 08:53 PM Click Here to See the Profile for La fieraSend a Private Message to La fieraEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
. I noticed that stock 84-87 brakes heat up quickly!


Patrick, you being an engineer I thought you have the brakes upgraded for the forecasted HP. How did you spect the stock brakes to keep up with the demands?
Sometimes is a matter of trial and error, I've been there myself! "Keep pounding" like we say here in NC!
IP: Logged
pmbrunelle
Member
Posts: 3323
From: Grand-Mère, Québec
Registered: Sep 2008


Feedback score: N/A
Leave feedback





Total ratings: 54
Rate this member

Report this Post05-17-2020 09:04 PM Click Here to See the Profile for pmbrunelleClick Here to Email pmbrunelleSend a Private Message to pmbrunelleEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by La fiera:
How did you spect the stock brakes to keep up with the demands?


I didn't!

I suppose you could build up every system of a project car, and then fire up a finished car and go driving.

In addition to working on the car in the garage, I wanted to drive it even though it's not finished! Driving the car is also how you discover problems.
IP: Logged
La fiera
Member
Posts: 1519
From: Mooresville, NC
Registered: Jun 2008


Feedback score:    (7)
Leave feedback

Rate this member

Report this Post05-17-2020 09:31 PM Click Here to See the Profile for La fieraSend a Private Message to La fieraEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by pmbrunelle:


I didn't!

I suppose you could build up every system of a project car, and then fire up a finished car and go driving.

In addition to working on the car in the garage, I wanted to drive it even though it's not finished! Driving the car is also how you discover problems.


Keep at it!!!! Good job mate!!

IP: Logged
pmbrunelle
Member
Posts: 3323
From: Grand-Mère, Québec
Registered: Sep 2008


Feedback score: N/A
Leave feedback





Total ratings: 54
Rate this member

Report this Post05-22-2020 12:21 AM Click Here to See the Profile for pmbrunelleClick Here to Email pmbrunelleSend a Private Message to pmbrunelleEdit/Delete MessageReply w/QuoteDirect Link to This Post
There is a small puddle of oil on top of the transmission, and it's not coming from the turbo. The turbo is dry.

The shifter shaft which penetrates the case is wet, and the breather vent also looks wet with oil. I'm not exactly sure.

Any opinions regarding this issue with my Muncie 4-speed?
IP: Logged
PFF
System Bot
ericjon262
Member
Posts: 2653
From: everywhere.
Registered: Jan 2010


Feedback score:    (10)
Leave feedback





Total ratings: 62
Rate this member

Report this Post05-22-2020 02:36 AM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
possible that the trans was over filled? that would be my first guess, but it's been ages since I looked at an old 4 speed.

------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

cognita semper

http://www.fiero.nl/forum/Forum2/HTML/119122.html

IP: Logged
claude dalpe
Member
Posts: 82
From: montreal,quebec,canada
Registered: Feb 2009


Feedback score: (1)
Leave feedback

Rate this member

Report this Post05-22-2020 09:43 AM Click Here to See the Profile for claude dalpeClick Here to Email claude dalpeSend a Private Message to claude dalpeEdit/Delete MessageReply w/QuoteDirect Link to This Post
and the breather vent also looks wet with oil. I'm not exactly sure.
Like ericjon262 said maybe over filled? Or your breather not working properly ! or your shifter shaft is loose in the case (I suppose you had put a new seal there)
IP: Logged
pmbrunelle
Member
Posts: 3323
From: Grand-Mère, Québec
Registered: Sep 2008


Feedback score: N/A
Leave feedback





Total ratings: 54
Rate this member

Report this Post05-22-2020 11:04 PM Click Here to See the Profile for pmbrunelleClick Here to Email pmbrunelleSend a Private Message to pmbrunelleEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'll check the transmission oil level this weekend.

Some yahoo put a turbo above the transmission, which makes that job more tricky
IP: Logged
ericjon262
Member
Posts: 2653
From: everywhere.
Registered: Jan 2010


Feedback score:    (10)
Leave feedback





Total ratings: 62
Rate this member

Report this Post05-23-2020 01:09 AM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by pmbrunelle:

I'll check the transmission oil level this weekend.

Some yahoo put a turbo above the transmission, which makes that job more tricky



Engineers are jerks aren't they! lol!

------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

cognita semper

http://www.fiero.nl/forum/Forum2/HTML/119122.html

IP: Logged
La fiera
Member
Posts: 1519
From: Mooresville, NC
Registered: Jun 2008


Feedback score:    (7)
Leave feedback

Rate this member

Report this Post05-23-2020 11:07 AM Click Here to See the Profile for La fieraSend a Private Message to La fieraEdit/Delete MessageReply w/QuoteDirect Link to This Post
Hey Patrick! How much HP are you expecting your engine to produce? Be gentle with that Muncie, they don't like sudden bursts of torque.
It will last a lot longer if you can program boost by RPM or MPH. Just a thought, keep up the good job!
IP: Logged
pmbrunelle
Member
Posts: 3323
From: Grand-Mère, Québec
Registered: Sep 2008


Feedback score: N/A
Leave feedback





Total ratings: 54
Rate this member

Report this Post05-23-2020 12:15 PM Click Here to See the Profile for pmbrunelleClick Here to Email pmbrunelleSend a Private Message to pmbrunelleEdit/Delete MessageReply w/QuoteDirect Link to This Post
I would guess in the 250 to 300 hp range when everything is working right. For now though, I am running off the wastegate spring while I solve other problems. Increasing the boost with the electronic solenoid is a project for later.

I remember that you split open the smooth case on your Muncie! I have the ribbed case (from a V6 Fiero) on mine, so hopefully it is stronger than the smooth version.

My hope is that this turbo setup does not shock-load the transmission much more than a stock 2.8 V6. After an upshift at WOT, when I get back on the gas and release the clutch pedal, the manifold pressure should be close to atmospheric. So during the shock-load of the gear change, the engine torque is not too high.

Because of the turbo lag, it takes about 0.3 to 0.4 seconds once I'm in gear for full boost to return. I think that the turbo lag makes the re-application of torque a gentle process for the transmission.

The MS3 has a flat-shift feature to maintain the boost as much as possible during the shifts; I think I will avoid using this feature, to be more gentle on the transmission.

I never had a turbo car before. I thought that maybe I would be bothered by the turbo lag, but finally I think it gives the car a special character. The lag is like foreplay before full boost.
IP: Logged
La fiera
Member
Posts: 1519
From: Mooresville, NC
Registered: Jun 2008


Feedback score:    (7)
Leave feedback

Rate this member

Report this Post05-23-2020 03:57 PM Click Here to See the Profile for La fieraSend a Private Message to La fieraEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by pmbrunelle:

The MS3 has a flat-shift feature to maintain the boost as much as possible during the shifts; I think I will avoid using this feature, to be more gentle on the transmission.

I never had a turbo car before. I thought that maybe I would be bothered by the turbo lag, but finally I think it gives the car a special character. The lag is like foreplay before full boost.


The good thing about Flat-shift is that you can fine tune it to how strong the engine comes into power.
You can also use it to keep the RPMs of the turbo up thus avoing lag.
Another antilag trick is to retard on deceleration (foot off the throttle) at the lower part of the timing table,
lets say from 7000 to 4000 RPMs and at the same RPM window on the VE table you add fuel.

That will create violent explosions between the head and the turbo and as the expanding combusting gas goes past
the turbine at high speed, even with the throttle closed the turbo is turning at high speed and creating boost, once on the throttle again
and hang on for your life!

Yes it creates A LOT of heat in the exhaust, they'll glow RED. But you can have that only at high RPMs like I said before.
To cool down the pipes all you have to do is keep it rich lets say from 3950 to 3500 and advance the timing to about 44-47,
below 3500 go back to normal fueling keeping the timing normally hi.

Every time you do that there will loud BANGS and visible fire out of your exhaust! That's foreplay
IP: Logged
ericjon262
Member
Posts: 2653
From: everywhere.
Registered: Jan 2010


Feedback score:    (10)
Leave feedback





Total ratings: 62
Rate this member

Report this Post05-26-2020 03:30 AM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by pmbrunelle:

I remember that you split open the smooth case on your Muncie! I have the ribbed case (from a V6 Fiero) on mine, so hopefully it is stronger than the smooth version.


From what I remember reading before I put an F23 in my car, the V6 4 speed is slightly stronger than a getrag 282, the downside being that it doesn't have overdrive, so it's not as hwy friendly.

------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

cognita semper

http://www.fiero.nl/forum/Forum2/HTML/119122.html

IP: Logged
pmbrunelle
Member
Posts: 3323
From: Grand-Mère, Québec
Registered: Sep 2008


Feedback score: N/A
Leave feedback





Total ratings: 54
Rate this member

Report this Post05-26-2020 12:13 PM Click Here to See the Profile for pmbrunelleClick Here to Email pmbrunelleSend a Private Message to pmbrunelleEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by La fiera:
That will create violent explosions between the head and the turbo and as the expanding combusting gas goes past
the turbine at high speed, even with the throttle closed the turbo is turning at high speed and creating boost, once on the throttle again
and hang on for your life!

Yes it creates A LOT of heat in the exhaust, they'll glow RED.


I am not ready to start beating the crap out of my exhaust. This build is too new; I am not ready to break it, yet!
However, I suspect a time will come when I have the itch to make the torque come back faster.

For example, now that the MAP stabilises at 155 kPa, I'm convinced that the engine needs more boost...

 
quote
Originally posted by ericjon262:
From what I remember reading before I put an F23 in my car, the V6 4 speed is slightly stronger than a getrag 282, the downside being that it doesn't have overdrive, so it's not as hwy friendly.


For some perspective, here in Québec, the speed limit on highways here is 100 km/h, and the typical maximum cruise speed is 110 km/h. Somewhat slower than the typical 80 mph (so I've read) highway cruise in the USA. My datalogs shows an engine speed of 3240 RPM for a vehicle speed of 110 km/h, which seems quite reasonable to me. I calibrated the VSS reading with a GPS. Eventually I'll probably install taller tires than the 215/60R14 tires I have on the car now.

However, this is the first 4-speed car I have ever driven. Compared to the 5-speeds (and to a lesser extent, 6-speeds) I have driven, I noticed that the wider gaps between gears make the car a bit harder to drive. Downshifts require bigger throttle blips, and it takes more concentration to match the revs right. I'm getting the hang of it though.

Durability-wise, I would guess that the Getrag 282 and the ribbed-case Muncie would be in the same league. People have blown up both boxes. When I was shopping for a replacement planet gear for the differential I found that the Muncie and Getrag 282 share the same part numbers for the differential (planet + satellite) gears.

What's bad for the durability of my transmission is the 1984 M19 gearing (3.53 1st, 4.10 final) vs. the M17 V6 gearing (3.31 1st, 3.65 final). Shorter gear ratios result in greater gear-separating force that can potentially split open the case.
IP: Logged
Previous Page | Next Page

This topic is 4 pages long:  1   2   3   4 
next newest topic | next oldest topic

All times are ET (US)

Post New Topic  Post A Reply
Hop to:

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery | Ogre's Cave
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock