The Twin Screw Thread
07-03-2012, 05:33 PM
#2312
Race Car
I am looking at going to somewhere between 6-8psi. Looking for safe dependable stress free boost of about 100HP. I have been watching SC threads somewhat but could never claim to have anywhere near the knowledge as most guys on this thread. Can you give me other suggestions on what I should be looking for with that level of boost. Will my stock clutch be OK? Will I need an intercooler? I do have new knock sensors. This is for 87 S4 with squirter block.
Dan
'91 928GT S/C
475hp/460lb.ft
07-04-2012, 02:27 PM
#2314
Rennlist Member
Centrifugals has a lower discharge temps then roots blowers, so most of them in low boost applications don't use an intercooler. I think I would have one on a roots system regardless of boost.
As far as thoughts of throwing a Begi FMU as far as you can and hitting it with a hammer, I have to disagree. Sharktuning is optimal but the Begi does just fine if it is set up right. Mine goes from 13-1 progressively down to 11-1 as boost increases and makes 370 whp at 6 psi with an auto transmission!
If I had an 87+ car I probably would just do the Sharktuner but the 85-86 cars don't have a very cost effective solution to reprogram the ecu (unfortunately).
As far as thoughts of throwing a Begi FMU as far as you can and hitting it with a hammer, I have to disagree. Sharktuning is optimal but the Begi does just fine if it is set up right. Mine goes from 13-1 progressively down to 11-1 as boost increases and makes 370 whp at 6 psi with an auto transmission!
If I had an 87+ car I probably would just do the Sharktuner but the 85-86 cars don't have a very cost effective solution to reprogram the ecu (unfortunately).
07-04-2012, 08:29 PM
#2315
All,
Thanks for the input. I have a Sharktuner running 11psi boost. I had originally had the BEGI since I was running the stock pump, but have since added the 044 and purchased PEMs. The car has been down for a while since I was wrapping the interior, so I am going to run it with the BEGI until I get time to get back on the dyno.
Later,
Woody
Thanks for the input. I have a Sharktuner running 11psi boost. I had originally had the BEGI since I was running the stock pump, but have since added the 044 and purchased PEMs. The car has been down for a while since I was wrapping the interior, so I am going to run it with the BEGI until I get time to get back on the dyno.
Later,
Woody
07-05-2012, 07:24 AM
#2316
Rennlist Member
So how have you remapped your ignition for safety and power ?
The New SharkTuner 1 is priced at a reasonable $1500 and I might be persuaded to extend the introductory off of $1250 USD.......
The New SharkTuner 1 is priced at a reasonable $1500 and I might be persuaded to extend the introductory off of $1250 USD.......
Centrifugals has a lower discharge temps then roots blowers, so most of them in low boost applications don't use an intercooler. I think I would have one on a roots system regardless of boost.
As far as thoughts of throwing a Begi FMU as far as you can and hitting it with a hammer, I have to disagree. Sharktuning is optimal but the Begi does just fine if it is set up right. Mine goes from 13-1 progressively down to 11-1 as boost increases and makes 370 whp at 6 psi with an auto transmission!
If I had an 87+ car I probably would just do the Sharktuner but the 85-86 cars don't have a very cost effective solution to reprogram the ecu (unfortunately).
As far as thoughts of throwing a Begi FMU as far as you can and hitting it with a hammer, I have to disagree. Sharktuning is optimal but the Begi does just fine if it is set up right. Mine goes from 13-1 progressively down to 11-1 as boost increases and makes 370 whp at 6 psi with an auto transmission!
If I had an 87+ car I probably would just do the Sharktuner but the 85-86 cars don't have a very cost effective solution to reprogram the ecu (unfortunately).
07-05-2012, 10:59 AM
#2317
Rennlist Member
I have a custom EZF chip made by Porken to progressively remove timing with boost and add timing off boost so I have better power at low RPM. S3's have a pretty good safety net with stock timing anyway but I wanted to be sure.
$1250 is better then $2K for sure, something to consider. My Begi system in conjunction with the pressure switch to force LH open loop at .5 psi and above works pretty good. When I had the disk style Vortech FMU and no pressure switch I was lean at vacuum/boost transition and way rich at high boost, it was far from optimal. With my current tune I get a bit of black smoke when I get on it hard but I think that is normal on boosted cars, my little A4 even does it a bit and it has enough computers and sensors to choke a horse!
$1250 is better then $2K for sure, something to consider. My Begi system in conjunction with the pressure switch to force LH open loop at .5 psi and above works pretty good. When I had the disk style Vortech FMU and no pressure switch I was lean at vacuum/boost transition and way rich at high boost, it was far from optimal. With my current tune I get a bit of black smoke when I get on it hard but I think that is normal on boosted cars, my little A4 even does it a bit and it has enough computers and sensors to choke a horse!
07-05-2012, 03:38 PM
#2318
Rennlist Member
Fair enough, you seem to have it pretty well sorted, although I am sure more optimisation is possible....
I have a custom EZF chip made by Porken to progressively remove timing with boost and add timing off boost so I have better power at low RPM. S3's have a pretty good safety net with stock timing anyway but I wanted to be sure.
$1250 is better then $2K for sure, something to consider. My Begi system in conjunction with the pressure switch to force LH open loop at .5 psi and above works pretty good. When I had the disk style Vortech FMU and no pressure switch I was lean at vacuum/boost transition and way rich at high boost, it was far from optimal. With my current tune I get a bit of black smoke when I get on it hard but I think that is normal on boosted cars, my little A4 even does it a bit and it has enough computers and sensors to choke a horse!
$1250 is better then $2K for sure, something to consider. My Begi system in conjunction with the pressure switch to force LH open loop at .5 psi and above works pretty good. When I had the disk style Vortech FMU and no pressure switch I was lean at vacuum/boost transition and way rich at high boost, it was far from optimal. With my current tune I get a bit of black smoke when I get on it hard but I think that is normal on boosted cars, my little A4 even does it a bit and it has enough computers and sensors to choke a horse!
08-20-2012, 10:53 AM
#2319
Supercharged
Rennlist Member
Rennlist Member
Join Date: May 2002
Location: Back in Michigan - Full time!
Posts: 18,925
Likes: 0
Received 59 Likes
on
33 Posts
I was pretty sure I had "cooked" a seal on the SCer last fall when I was attempting to hit 500RWHP. I was running a really small pulley that was overspinning the SCer. It was a gamble - I lost. I now have a 2.1L that is a direct bolt-on to replace the little 1.7L. That should put me at the 500 mark. I delayed and delayed pulling the SCer off but I couldn't delay any more. When I pulled it, there was 50wt blue oil everywhere! That seal was way worse than I had anticipated. The rotors are covered in oil. I'll bet I was ingesting a bit of oil which may be the cause for the lack of pull (plus I'm pretty sure I had a boost leak).
QUESTION: What is the green linoleum-like gasket material? Anyone have a source? Also, how have others cut those things? I kind of remember doing it once before but it's really foggy!
Here are some pics of the DR SCer with about 30k miles on it driven hard every time! Not bad considering.
QUESTION: What is the green linoleum-like gasket material? Anyone have a source? Also, how have others cut those things? I kind of remember doing it once before but it's really foggy!
Here are some pics of the DR SCer with about 30k miles on it driven hard every time! Not bad considering.
08-20-2012, 11:16 AM
#2320
Supercharged
Rennlist Member
Rennlist Member
Join Date: May 2002
Location: Back in Michigan - Full time!
Posts: 18,925
Likes: 0
Received 59 Likes
on
33 Posts
I decided to try using the stock intake manifold gasket under my Andy Keel Supermodel "pizza box" manifold. Andy originally used a rigid gasket material. It didn't completely seal, I suspected due to heat warping of the rather thin bottom plate. I reinforced the bottom plate, but thought the rubber gasket might help. In order to prevent crushing the stock rubber gasket, I cut some 1/8" thick spacers, which would allow a 1/3rd crush. Seemed like a good idea. The rubber gasket has a metal frame inside, which is good for resistance to blowing out from boost, but DR warned that the 1/3rd crush resulted in cut gaskets. Too late - I had already installed them. Well, 2 years later and about 25K miles, I pulled the SC, and sure enough, the gasket is a bit chopped up. BUT it's not exactly at the metal frame and none of the cuts ran across the seal. It looks bad, but I'm not sure what consequence it had. Some of the little tabs around the injector notch almost sheared off, but I'm not sure why they were more vulnerable. None of the splits resulted in pieces coming completely off. Also, the spacers were cut from cold rolled steel. A few of them got slightly crushed, which surprised me since I only torqued to 11 ft-lbs. I didn't notice this when I removed them, but I suspect the crushed ones were at the front due to the belt tension on the neck. The last pic shows some.
\
\Bill or anyone else running stock gaskets... I really like the idea of running stock gaskets. Would you still recommend 1/3 squish? More? Less?
08-20-2012, 11:54 AM
#2321
Rennlist Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Holy crap Andrew..has it really been 6 YEARS and 30k MILES... unbelievable!!
I am honestly surprised how well that older style system has help up, Kudos to you!! Not sure if you are aware but that is the ONLY "Series I" left from my first few systems. All the others were replaced to Series II. If you are interested in one of the newer style intakes I will give you a new lower raw casting for free and assist you getting anything else needed to upgrade. The timing looks to be perfect for both of us to do this. I am currently in the process of ordering some of the parts for another new system I am building and could piggyback anything you need, including the larger dual pass intercooler used in the S2.
In the end the intake would be like this and be much more robust....OH and easily use Stock Gaskets as it was designed that way.
OH, and just for fun, here is a pic of your recently acquired "Twin Screw" just before it was installed. :-)
Cheers,
Dave
I am honestly surprised how well that older style system has help up, Kudos to you!! Not sure if you are aware but that is the ONLY "Series I" left from my first few systems. All the others were replaced to Series II. If you are interested in one of the newer style intakes I will give you a new lower raw casting for free and assist you getting anything else needed to upgrade. The timing looks to be perfect for both of us to do this. I am currently in the process of ordering some of the parts for another new system I am building and could piggyback anything you need, including the larger dual pass intercooler used in the S2.
In the end the intake would be like this and be much more robust....OH and easily use Stock Gaskets as it was designed that way.
OH, and just for fun, here is a pic of your recently acquired "Twin Screw" just before it was installed. :-)
Cheers,
Dave
__________________
David Roberts
2010 Jaguar XKR Coupe - 510HP Stock - Liquid Silver Metallic
928 Owners Club Co-Founder
Rennlist 928 Forum Main Sponsor
www.928gt.com
928 Specialists on Facebook - 928Specialists
Sharks in the Mountains on Facebook - 928SITM
David Roberts
2010 Jaguar XKR Coupe - 510HP Stock - Liquid Silver Metallic
928 Owners Club Co-Founder
Rennlist 928 Forum Main Sponsor
www.928gt.com
928 Specialists on Facebook - 928Specialists
Sharks in the Mountains on Facebook - 928SITM
08-20-2012, 12:02 PM
#2322
Supercharged
Rennlist Member
Rennlist Member
Join Date: May 2002
Location: Back in Michigan - Full time!
Posts: 18,925
Likes: 0
Received 59 Likes
on
33 Posts
DR-
Yeah 6 years! Wow! I'll give you call later today/tomorrow. You're offer sounds really good.
BTW, I'm quite certain that the current setup will support the 2.1L blower. I'm going to have to relocate the ISV, but that's not a big deal. Everything else should be a cake walk.
Upgrading the intercooler might be worth it alone. Hmmmm....
Yeah 6 years! Wow! I'll give you call later today/tomorrow. You're offer sounds really good.
BTW, I'm quite certain that the current setup will support the 2.1L blower. I'm going to have to relocate the ISV, but that's not a big deal. Everything else should be a cake walk.Upgrading the intercooler might be worth it alone. Hmmmm....
08-20-2012, 12:09 PM
#2323
Rennlist Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
From Post #1038 on 06/06/2006... wow, never realized it was 6-6-6...scary :-)
https://rennlist.com/forums/3124088-post1038.html
Those were the days!!
https://rennlist.com/forums/3124088-post1038.html
Those were the days!!
08-20-2012, 12:10 PM
#2324
Drifting
[QUOTE=AO;9778162]I was pretty sure I had "cooked" a seal on the SCer last fall when I was attempting to hit 500RWHP. I was running a really small pulley that was overspinning the SCer. It was a gamble - I lost. I now have a 2.1L that is a direct bolt-on to replace the little 1.7L. That should put me at the 500 mark. I delayed and delayed pulling the SCer off but I couldn't delay any more. When I pulled it, there was 50wt blue oil everywhere! That seal was way worse than I had anticipated. The rotors are covered in oil. I'll bet I was ingesting a bit of oil which may be the cause for the lack of pull (plus I'm pretty sure I had a boost leak).
QUESTION: What is the green linoleum-like gasket material? Anyone have a source? Also, how have others cut those things? I kind of remember doing it once before but it's really foggy!
Andrew, its hard to tell from the pic but it looks like the bulk heavy gasket material that you can get from NAPA or any parts counter for heavy duty application like when making a gasket for a Detroit or cat diesel truck
QUESTION: What is the green linoleum-like gasket material? Anyone have a source? Also, how have others cut those things? I kind of remember doing it once before but it's really foggy!
Andrew, its hard to tell from the pic but it looks like the bulk heavy gasket material that you can get from NAPA or any parts counter for heavy duty application like when making a gasket for a Detroit or cat diesel truck
08-20-2012, 12:42 PM
#2325
Rennlist Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
DR-
Yeah 6 years! Wow! I'll give you call later today/tomorrow. You're offer sounds really good. BTW, I'm quite certain that the current setup will support the 2.1L blower. I'm going to have to relocate the ISV, but that's not a big deal. Everything else should be a cake walk.
Upgrading the intercooler might be worth it alone. Hmmmm....
Yeah 6 years! Wow! I'll give you call later today/tomorrow. You're offer sounds really good.
BTW, I'm quite certain that the current setup will support the 2.1L blower. I'm going to have to relocate the ISV, but that's not a big deal. Everything else should be a cake walk.Upgrading the intercooler might be worth it alone. Hmmmm....
Yes the newer intercooler is much larger as is the valley of the new intake. Also the IC coolant ports are both on the rear of the top plate, much simpler assembly, setup and install. With all components and ports on the top plate plus the tongue/groove perimeter seal of the upper and lower it is also easy for future maint. etc. You can pull the upper SC/IC/Intake assembly apart in one complete section without even disturbing the lower manifold if desired.
IF you do end up staying the with older intake, I still have my aluminum template for cutting the gaskets, can send it to you if needed.
Dave