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Ideola's Ultra Wide Body 931 Build (Master Thread)
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ideola  



Joined: 01 Oct 2004
Posts: 15318
Location: Woodstock IL

PostPosted: Sat Aug 25, 2007 3:25 am    Post subject: Ideola's Ultra Wide Body 931 Build (Master Thread) Reply with quote

[Updated 07 Aug 2009]
OK people, here's your chance! It's open season on Ideola's Ultra Wide Body 931 build! Anything goes! Comments & suggestions welcome! Derisive laughter and sarcastic naysayers will be tolerated with no reprisals! I will actively edit this entry as I make progress, evaluate alternatives, eliminate options, zero in on design choices, and complete execution. Once the build commences, I will post photos of everything here.

Block (see this thread for details and photos)
  • Custom-forged non-interference pistons, ceramic tops, teflon skirts, 87.5mm bore, 8.0:1CR (Diamond Racing) : completed Jun 2006
  • Stroke increased to 90.75mm (Performance Crankshaft) : completed Jun 2006
  • Block bored and align-honed (Holbrook Racing) : completed Aug 2006
  • Custom forged, lightened chrome moly rods (Crower) : completed Sep 2007
  • Vibratech POR174M Engine Mounts : acquired Mar 2007
  • O-ringing : completed Oct 2007
  • Complete balancing of rotating assembly : will be completed just prior to block assembly
  • Pace Products Dry Sump : acquired June 2009, but they sent me the wrong pump, should have correct items in 4-6 weeks
  • xxxxx Oil pan baffles (local fabricator) : ruled out (superfluous with scraper & dry sump)
  • xxxxx Crank knife edging & further lightening : ruled out
  • xxxxx Crank girdle : ruled out (not necessary given my HP goals)
  • xxxxx Custom aluminum flywheel (Fidanza) : ruled out due to confirmed fitment issues
  • xxxxx Custom crank scraper (Ishihara-Johnson) : ruled out, not necessary with dry sump


Cooling System (see this thread)

Head
  • Cometic 5-Layer MLS head gasket: acquired Apr 2009 (see this thread)
  • Modified stock intake manifold: Completed 05 Mar 2008 (see update in this thread)
  • Franco variable timing gear : acquired in 2005 (see this thread)
  • "Eurorace" head + lightened valve train : acquired Jul 2009 (see this thread)
  • Performance Valve Springs : acquired Apr 2009 (see this thread)
  • ARP head studs : acquired July 2008 (see this thread)
  • Piper solid lifters : acquired 15 May 2008 (see this thread)
  • Integral Cams "hot street" grind : acquired 11 Apr 2008 (see this thread)
  • xxxxx Performance Valves : ruled out in favor of off-the-shelf package from EMW
  • xxxxx Raceware studs : ruled out in favor of ARP head studs (see this thread for details)
  • xxxxx Extrude honing of intake, head, exhaust, and turbo : ruled out (not enough bang for the $$$)
  • xxxxx Composite head gasket with crush rings (Lubbock) : ruled out in favor of Cometic MLS


Turbo (see this thread)
  • Custom water-cooled K26/K27 hybrid turbo : acquired 04 June 2008
  • Ceramic coating of exhaust manifold, J-pipe, turbine housing : acquired 04 June 2008
  • Modified 951 FMIC : acquired June 2009 (see this thread)
  • Boost controller : actively shopping
  • Boost enhancer : acquired July 2008
  • Wastegate rebuild kit : acquired from EBS 12 May 2008
  • Turbowerx Oil Scavenge Pump : acquired Sep 2008
  • Custom after-cooler : in design phase
    This is a concept I've been developing for about 3 months. Essentially, it will be an additional stage of chargecooling, post FMIC, with the goal of reducing temps to below ambient. There are some feasibility questions that have to be addressed; if the concept turns out to be feasible, I will release more details at that time. Hint: my design does NOT require a consumable medium, such as water or NOS spraying on the FMIC.
  • xxxxx Heat wrap for turbine : ruled out in favor of ceramic coating
  • xxxxx Andial 1.2 bar spring : ruled out in favor of high-end boost controller


Engine Management, Fuel Delivery & Ignition (see this thread for details)
  • DTA Fast Pro 60 ECU : acquired Oct 2008
  • Custom aluminum extruded fuel rail : acquired Sep 2008
  • Sard Adjustable FPR : acquired Sep 2008
  • Ford EDIS : acquired Sep 2008
  • Crank trigger wheel : acquired Sep 2008, but I may replace with off-the-shelf unit from 034 Motorsport
  • Cam trigger wheel : actively shopping
  • Injectors : TBD; currently planning to run E85, so will need uprated injectors capable of delivering enough fuel without maxing the duty cycle
  • Fuel Safe Enduro ED115 fuel cell : acquired Oct 2008
  • Wide-band O2 setup : in shopping queue; planning to get an LC-1 or PLX Devices setup
  • Instrumentation : in design phase; see this thread
  • High capacity fuel pump : in design phase; currently planning to run a Bosch 044 fuel pump, unless a more suitable and affordable alternative can be identified that is also E85-compatible
  • Custom steel braided fuel line : in design phase


Driveline (see this thread)
  • Lightweight (aluminum) 915 pressure plate (stock part) : acquired Jun 2007
  • Stock clutch disk (stock part) : acquired in 2006
  • Race-prepped G31 with bonafide snailshell LSD (local PCA member) : acquired in 2005-6; completed Apr 2007
  • Custom polyurethane solid transmission mounts : acquired Nov 2008
  • Modified hybrid G31/Audi-based shift linkage : completed Jul 2009; see this thread
  • Stock replacement parts : in shopping queue (pilot bearing, release bearing, guide sleeve, slave cylinder, fork bearings)
  • Transaxle oil cooler : acquired Jul 2008
  • Electric oil scavenge pump : acquired Sep 2008


Brakes (see this thread for details)
  • 951 4-pot Brembo calipers : acquired May 2008
  • Tilton 600 series 3-pedal assembly : acquired May 2009
  • Zimmerman slotted rotors : acquired May 2009
  • Pagid Sport T0377 pads : acquired May 2009
  • Brembo rebuild service : at rebuilders


Suspension, Wheels & Tires (see this thread for details)
  • 7x16/9x16 Rials : acquired Aug 2008
  • 7.5x17/10x17 Borbets : acquired Mar 2009
  • Rebuilt Atsco power steering rack : in shopping queue; see this thread for details on my power steering conversion for early cars
  • Other power steering components : in shopping queue; need pump rebuild kit, new reservoir/filter, Racer's Edge delrin bushings
  • Sway bars: 25.5mm/18mm front/rear : acquired May 2008
  • 400 lb front springs : acquired in 2005
  • 30mm torsion bars : acquired in 2005
  • 951 alloy rear suspension setup : acquired Oct 2007
  • Mookeh adjustable camber plates : acquired Oct 2008
  • CV boot kits : acquired Jan 2009
  • Paragon's Weltmeister/Racer's Edge 944 Cup bushing package : acquired Apr 2009
  • Racer's Edge Delrin bushings for sway bars : acquired June 2009
  • Rennbay geometry correcting ball joint kit : acquired Apr 2009
  • Elephant Racing geometry correcting tie rod kit : acquired May 26 2009
  • Ground Control front struts with Koni adjustable inserts : acquired Dec 2008
  • Huntley Racing rear coilover shocks : acquired Dec 2008
  • Tires (body kit will accommodate up to 12"-wide tires(!!!) : TBD
  • xxxxx NOS steering rack from EBS : ruled out in favor of power steering conversion
  • xxxxx Fastech Racing solid torsion mounts : ruled out, may execute in a phase II suspension upgrade
  • xxxxx SpeedForce Racing mild steel A-Arms : ruled out, may execute in a phase II suspension upgrade
  • xxxxx Elephant Racing monoball / solid bushings (spring plate, trailing arm, and a-arm) : ruled out, may execute in a phase II suspension upgrade


Electrics
  • Battery relocation : in design phase
  • Odyseey ER40 racing battery : in shopping queue
  • IMI Gear Reduction Starter : acquired June 2009; see this thread
  • CS130D 160 amp alternator : acquired May 2009
  • Axle-driven pulley for alternator : completed June 2009 (see this thread for details)
  • Wiring harness : in design phase; evaluating conventional alternatives (Painless and EZ2Wire), as well as the ISIS Intelligent Multiplex System (see this thread)


Body & Interior (see this thread for details and photos)
  • Autopower Roll Bar + u-weld-it full cage : acquired in 2006, installation scheduled for late Oct 2008
  • GTR-style ultra wide body front clip : acquired in May 2009
  • AIR Holbert-style rear fenders, fiberglass : acquired in 2005
  • Fiberglass hood : acquired May 2009
  • Fiberglass doors: acquired May 23 2009
  • Lindsey Racing Stage V Header Panel : acquired 08 May 2008
  • Lexan hatch : acquired in Mar 2007
  • Lexan quarter windows with naca ducts : acquired in Mar 2007
  • Lexan door windows : actively shopping
  • Deutsch-9 dual-projector fixed headlight conversion: actively shopping
  • Chassis prep, media blast and DP90 : completed Jan 2009
  • Add'l chassis lightening : completed Oct 2008; removed ALL sound deadening material, removed the rear hatch area deck, and a lot of the non-structural sheet metal in the rear of the car.
  • Chassis fabrication : completed Jan 2009
  • Manual window regulators : acquired in Apr 2007
  • Tear drop side view mirrors : acquired Jul 2009
  • Fire suppression : TBD
  • xxxxx Chemically stripped chassis : ruled out in favor of media blasting
  • xxxxx Manual driver-side-only mirror : acquired in Jun 2007, ruled out in favor of teardrop mirrors from AIR or GT Racing
  • xxxxx Custom tail light assemblies : ruled out, want to retain vintage tail lights

_________________
15 981 GTS | 04 955 Turbo | 88 924S SE | 82 931 (x2) | 81 937 | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 80 US 931 | 80 931 GTR | 79 Sebring | 78 D-Prod (x2) | 78 Poli-Form | 78 Limited Edition | 77 Martini


Last edited by ideola on Sat Aug 08, 2009 11:39 am; edited 66 times in total
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Rasta Monsta  



Joined: 12 Jul 2006
Posts: 11319
Location: PacNW

PostPosted: Sat Aug 25, 2007 3:50 am    Post subject: Reply with quote

Nice f***in plan, man. Idiot!

(laughs derisively)
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ideola  



Joined: 01 Oct 2004
Posts: 15318
Location: Woodstock IL

PostPosted: Sat Aug 25, 2007 3:52 am    Post subject: Reply with quote



oh.

bwahahahahahaha
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15 981 GTS | 04 955 Turbo | 88 924S SE | 82 931 (x2) | 81 937 | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 80 US 931 | 80 931 GTR | 79 Sebring | 78 D-Prod (x2) | 78 Poli-Form | 78 Limited Edition | 77 Martini
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Khal  



Joined: 26 Sep 2003
Posts: 4858
Location: Dark and cold and windy, Vancouver, Canada

PostPosted: Sat Aug 25, 2007 4:00 am    Post subject: Reply with quote

So, you started in 2005? Only two years and you're already a third of the way there... might even be finished by 2011 at this rate, eh?!

(wonder what a Cayman will be worth in 2011..?)



Of course I'm only kidding. Quite the list of mod's. Should be a serious weapon...
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ideola  



Joined: 01 Oct 2004
Posts: 15318
Location: Woodstock IL

PostPosted: Sat Aug 25, 2007 4:42 am    Post subject: Reply with quote

Yep, I acquired the car that is serving as the platform for this project in 2005, and started the plan rolling forward way back then.

Unfortunately, I was served with divorce papers on 24 Jan 2006, which pretty much stopped the project dead in its tracks. Legal orders mandated that I not move, modify or touch any assets until the divorce was final.

Then pile on to that big mess the following:
- one of my P-cars was stolen on 03 Jan 2006 (luckily, we recovered it, albeit not without some consequence...I'll tell that sordid tale in an upcoming post
- delayed piston delivery (3 months instead of 4 weeks as promised)
- delayed crank delivery (4 months instead of 4 weeks as promised)
- delayed block work (couldn't finish hone until the pistons were done)
- bad info on the stroker build (you can't do a stroker without notching the block or making custom rods)
- getting ripped off on some body work and panels by Wes & crew

Well, you get the idea.

Good news is that I've been able to get the project rolling again, and hopefully will be able to keep it moving now.
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15 981 GTS | 04 955 Turbo | 88 924S SE | 82 931 (x2) | 81 937 | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 80 US 931 | 80 931 GTR | 79 Sebring | 78 D-Prod (x2) | 78 Poli-Form | 78 Limited Edition | 77 Martini
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Min  



Joined: 04 Nov 2002
Posts: 2365
Location: Vernon, British Columbia, Canada

PostPosted: Sat Aug 25, 2007 4:49 am    Post subject: Reply with quote

Only thing I have to say on it, I've already said. Trying to make cis run that motor is like trying to get more fuel enrichment by tricking your coolant sensor on a stock EFI system (you know what corky bell thinks of that since you read his book). Its like using a bandaid for arterial bleeding. You have a monster build in the making, It would really be unfortunate for something to go wrong becuase CIS turned out to not be adequate.

Did you o-ring the block? Its not on your list, if you decided not too, any particular reason why not?

Min
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ideola  



Joined: 01 Oct 2004
Posts: 15318
Location: Woodstock IL

PostPosted: Sat Aug 25, 2007 5:32 am    Post subject: Reply with quote

Let me be explictly clear on the topic of CIS vs. EFI
1. I have no doubts about the superiority of EFI/EDIS over stock CIS and ignition.
2. I am NOT going to dial up 25 psi of boost and expect the motor to run with CIS.
3. I am going to add EFI and DIS. It is most definitely in my plans, and I will add it.
4. As I've stated, I'm going to get the motor running with CIS. I will have boost completely shut down to begin with, just to get the motor fired up. Depending on available budget, I want to get a baseline dyno run with NO boost. That should tell me quite a bit about the suitability of CIS moving forward. It will also allow me to document power gains attributable to a wide variety of variables that I will incrementally enable throughout the development phase (e.g., incremental increases in boost, FMIC, aftercooling, fuel delivery, etc.).
5. I am already planning to install a modified CIS setup based on additional injectors and a supplemental fuel distributor. I already have all of the components. The intake mods will accommodate additional injectors. I am currently evaluating options for how to drive / trigger the additional fuel delivery via the extra dizzy.
6. My ignition distributors will be rebuilt before install, and at least one of them will be recurved to address initial ignition concerns. Granted, not as good as DIS, but it will work in the interim. I have three 931 dizzys to work with. One will be retained in stock form, and the other two will be recurved as needed. A rebuilt, recurved ignition dizzy costs about $150 with core. Much cheaper than trying to source, install, and debug DIS.
7. When the time comes, I will slowly dial up the boost. I will start at 3 psi, and slowly and incrementally work my way up, probably no higher than 9 or 10 psi. If I'm not mistaken, 9 psi is stock on a eurospec 931, which presumably runs off of stock CIS. There are PLENTY of examples of other people running stock CIS at those boost levels on US cars as well. Granted, the stroking adds a variable, but I believe my modified intake, CIS, and ignition setups will help keep me out of too much trouble.
8. Final boost numbers will not be determined or dialed in until I complete the design and acquisition of an EFI/DIS setup. I am still researching whether I want to go with MS + EDIS, or if I will go with a pro setup. Based on my total project budget, either approach will be around 10% of the total project cost. Done properly (meaning, not using used junkyard parts) MS EFI is nearly as costly as a pro setup. I will not be putting ANY used junkyard parts on this build. If I convert one of my street cars, sure, taking the cheap junkyard approach will be fine. But I'm not going to risk a five figure project on cheap junkyard parts.

Now, if after all that, everyone is STILL convinced that a modified CIS will not be sufficient to run 6-10 psi of intercooled boost, I will be happy to entertain any data points that clearly indicate why it won't work. What I'm saying is, I can be convinced to change my mind, but to be convinced, it would be nice to see facts and figures and not just opinions. For now, I am still convinced that adding EFI right off the bat will just be introducing too many variables.

Min wrote:
Did you o-ring the block? Its not on your list, if you decided not too, any particular reason why not?

I forgot to add to the list the custom composite head gasket. Multi-Layer-Steel (MLS) head gaskets are not available without tremendous R&D expense, at least based on all of the inquiries I've made. I've heard too many horror stories about Copper. So I've opted to go with composite. The composite head gasket includes metal crush rings that insert into the gasket bores for the cylinder. According to the supplier, these crush rings essentially act as an o-ring, and work better than copper given the challenges of mating aluminum to copper to iron. The composite material has superior heat tolerance characteristics over conventional (stock) gaskets.

But frankly, this is one of my biggest concerns when I start getting into the higher boost numbers. I haven't ruled out o-ringing entirely, and I still have time to implement it, given the stage I'm at in the build. I will probably go thru one more round of serious inquiry on the subject prior to doing the initial build. One of the variables I'm trying to sort out is whether the boost numbers I want to produce are actually achievable; if they are, it will most definitely require a hybrid turbo, which I will have to source, design and build. Not insurmountable, but also not a certainty at this point. So, I won't have a final decision on o-ringing until I have relative certainty as to what level of boost I can realistically target.
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15 981 GTS | 04 955 Turbo | 88 924S SE | 82 931 (x2) | 81 937 | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 80 US 931 | 80 931 GTR | 79 Sebring | 78 D-Prod (x2) | 78 Poli-Form | 78 Limited Edition | 77 Martini
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Rasta Monsta  



Joined: 12 Jul 2006
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PostPosted: Sat Aug 25, 2007 6:17 am    Post subject: Reply with quote

There is a guy here who has run dual fuel dizzies & 8 injectors. You might do well to ask him whether he would do it again.
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Min  



Joined: 04 Nov 2002
Posts: 2365
Location: Vernon, British Columbia, Canada

PostPosted: Sat Aug 25, 2007 6:25 am    Post subject: Reply with quote

ideola wrote:
6. My ignition distributors will be rebuilt before install, and at least one of them will be recurved to address initial ignition concerns. Granted, not as good as DIS, but it will work in the interim. I have three 931 dizzys to work with. One will be retained in stock form, and the other two will be recurved as needed. A rebuilt, recurved ignition dizzy costs about $150 with core. Much cheaper than trying to source, install, and debug DIS.


Seems like a waste of money to me. But its your money, do with it as you will.

ideola wrote:
Done properly (meaning, not using used junkyard parts) MS EFI is nearly as costly as a pro setup. I will not be putting ANY used junkyard parts on this build.


huh? .... seriously .... post your spreadsheet detailing that please. I'd love to see it.

ideola wrote:
that clearly indicate why it won't work.What I'm saying is, I can be convinced to change my mind, but to be convinced, it would be nice to see facts and figures and not just opinions.


See, thats the thing, why would I bother with facts and figures? ... its your build, blow it up if you want. I was simply mentioning my misgivings in the hopes you would entertain commonsense. Seriously .... two fuel distributors? multiple sets of fuel injectors? so your building yourself a completely untested setup ... for what again? to avoid the complication of a simple EFI installation? I got lizards 928 running over instant messager, I also got Flosho's 931 running over instant messanger, I installed and started a datsun 280z, it started first turn of the key, and idled almost perfectly...... same goes for my porsche.

screw the cis, you'd be better off with carbs.

ideola wrote:
For now, I am still convinced that adding EFI right off the bat will just be introducing too many variables.


Judging from your list of modifications, I'd say your already well into the 'too many variables' territory. really really really far into it in fact. Sounds to me like your just afraid of doing it. Its not like you can't install it on one of your other setups to see how darn simple it really is. Before putting it on this thing. Flosho had some problems with his setup, it was becuase his intake air tempurature sensor wasn't connected properly. Fixed that, and it fired right up. Lizard had some problems with his, it was becuase he had setup the initial variables incorrectly, Fixed that, it fired right up.

ideola wrote:
But frankly, this is one of my biggest concerns when I start getting into the higher boost numbers. I haven't ruled out o-ringing entirely, and I still have time to implement it, given the stage I'm at in the build. I will probably go thru one more round of serious inquiry on the subject prior to doing the initial build. One of the variables I'm trying to sort out is whether the boost numbers I want to produce are actually achievable; if they are, it will most definitely require a hybrid turbo, which I will have to source, design and build. Not insurmountable, but also not a certainty at this point. So, I won't have a final decision on o-ringing until I have relative certainty as to what level of boost I can realistically target.


I'm trying a o-ringed block with a stock headgasket. Should be interesting to see what happens with that. I look forward to seeing your progress.

Min
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Lizard  



Joined: 03 Nov 2002
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Location: Abbotsford BC. Canada

PostPosted: Sat Aug 25, 2007 6:33 am    Post subject: Reply with quote

why not dry sump it too.


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ideola  



Joined: 01 Oct 2004
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Location: Woodstock IL

PostPosted: Sat Aug 25, 2007 7:18 am    Post subject: Reply with quote

OK, Min, it's put up or shut up time. If you can provide a comprehensive list of EVERY part, along with a complete instructional guide documenting the complete installation process, soup to nuts, and PROVE to me that it can be done for less than $1500, and will work the first time I turn the key, you win. I'll change my plans and include EFI in the first stage build. Hell, I might even divert some of my project funds to a preliminary setup on my 941 if it's as cheap and easy as you suggest. Trust me, I'd love nothing better than for you to win that argument!!!! Don't forget to include baseline ignition curves and fuel maps, 'cause I'll be needing all of that.

It would be wonderful just to have the IM logs from your sessions with Lizard. I'm sure they would be revealing to everyone. And just so you don't misinterpret...I have NO doubt re: your ability to get EFI up and running, at least eventually. But frankly, of all the modifications I'm tackling, EFI is still one of the murkiest, least documented areas of engine tuning I've uncovered. No one in the open-source world has the discipline to document the process with any degree of precision, and no one in the pro tuner market is going to disclose their secrets.

So, am I scared to try EFI? No. Am I intimidated by the lack of clear concise good information? Yes. The only decent writeup I've seen is Nick's, and believe me I've read it over and over. But it is by no means a bullet proof manual, and there are a couple of areas where the phrase "you're on your own" comes into play.

As for my insistence with dealing in facts and figures? Because that's what convinces people. Opinions might be persuasive, but facts and figures are convincing. I want to be convinced, not persuaded.

Lizard, I've considered dry sumping. I attempted to source some lightly used parts, but that deal fell thru. Short of finding a lightly used setup, it will cost about $2500 to acquire the pump, all of the fittings, modify the pan, fabricate the brackets, etc. A fully-plumbed Accusump is in the neighborhood of $600. A fully-plumbed vacuum assist sump is in the neighborhood of $1500. As I noted, I'm leaning heavily toward Accusump because I think it will give me everything I need for my application. I have almost (but not quite) ruled out dry sumping because I just don't see its added advantages justifying a 3x cost of an Accusump. I am still investigating and considering the vacuum assist approach, but the biggest barrier to that approach is affordably fabricating a bracket and finding a place to mount the drive pulley.

I should mention, unlike other guys on this board, I do not have access to fabrication equipment. I acknowledge that as one of my most significant constraints. So its important to bear in mind my development costs are affected to a large degree by what I can affordably have fabricated. Some of those costs are worthwhile (in the case of the intake mods and some of the aftercooling stuff I'm working on) because I have a source who has agreed to do the work for what I deem to be reasonable charges. Doing wholesale fabrication is beyond my means, both in terms of dollars and personal technical proficiency. That constraint necessarily has an impact on some of my design decisions.
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15 981 GTS | 04 955 Turbo | 88 924S SE | 82 931 (x2) | 81 937 | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 80 US 931 | 80 931 GTR | 79 Sebring | 78 D-Prod (x2) | 78 Poli-Form | 78 Limited Edition | 77 Martini
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ideola  



Joined: 01 Oct 2004
Posts: 15318
Location: Woodstock IL

PostPosted: Sat Aug 25, 2007 7:56 am    Post subject: Reply with quote

By the way, here is the post I was thinking, which corroborates my previous investigations into the matter, confirming that done correctly and completely, an EFI/DIS conversion is in the $1500 range. Also, a quick search on EFI will return scores of posts on the topic, NONE of which evangelize the cost effectiveness of ease of converting. Hell, if it were easy and cheap, we'd all be doing it. EFI is clearly NOT a trivial undertaking, even less so for a first-timer.

That said, here's another challenge: I will personally provide all the frosty beverages you can drink to anyone who wants to come to Detroit and help me source, install, tune and troubleshoot EFI for less than $1500. If the car doesn't start on the first try, you reimburse me for the beverage.
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15 981 GTS | 04 955 Turbo | 88 924S SE | 82 931 (x2) | 81 937 | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 80 US 931 | 80 931 GTR | 79 Sebring | 78 D-Prod (x2) | 78 Poli-Form | 78 Limited Edition | 77 Martini
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bass gt  



Joined: 02 Dec 2004
Posts: 971
Location: Johannesburg for now!!

PostPosted: Sat Aug 25, 2007 8:14 am    Post subject: Reply with quote

Dan,

Nothing to add here, sounds great!! If you are going to go with the CIS as an interim solution, get yourself a wideband lambda sensor plumbed into the exhaust, with a nice clear display. If the worst should happen, at least you may see it coming and get off the gas before the worst might happen. Even after the EFI addition, they are a nice telltale to have.

Good Luck,

Steve
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bruce76-924  



Joined: 22 Feb 2007
Posts: 105
Location: Bradford, England

PostPosted: Sat Aug 25, 2007 8:25 am    Post subject: Reply with quote

Rasta Monsta wrote:
There is a guy here who has run dual fuel dizzies & 8 injectors. You might do well to ask him whether he would do it again.


I think you already know the answer to that one ...................... not a chance. Granted it works and the power is there, but cold starting is an art and idle emissions are way too high. Never again, Efi is the only real way of doing it ( it just wasn't an option at the time when mine was first put together). Ignition wise, I've tried recurved distributors, ignition amplifiers, peformance coils etc and they all seem a long winded compromise compared to going the EDIS route (especially when there are a few helpful guys on the board for EDIS/MS troubleshooting)

Cheers, Bruce.
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bass gt  



Joined: 02 Dec 2004
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Location: Johannesburg for now!!

PostPosted: Sat Aug 25, 2007 9:03 am    Post subject: Reply with quote

Dan,

Definately o ring the block. It's a small job to do while the block is out and it works a treat. Trust me on this one
Regarding your plans for X/Y/Z levels of boost. Don't think in these terms. Do your calcs and choose the turbo carefully for the power you want. If you say you want 300 BHP, and fit the appropriate turbo, it wont suddenly support 400 BHP just by winding the boost up. Don't forget, the heat rise from the turbo will be an almost exponential rise. Just piling in more boost will not keep adding X BHP. You will quickly notice that whereas the first 1 psi provided a given HP jump, keep winding it up and you will see that rate of increase quickly diminishes.
Now given that the GTR's ran at 2.4 litres, and made 450+ BHP, you get a point of reference. However, bear in mind that the IC's on the GTR's was a monster, with lag being of little concern. These were race cars after all. ON/OFF, and not much in between.
Now looking at your specs, with the right fuelling and ignition you can shoot for big numbers. But accept that the higher you go, the more your low end response will suffer. At 2.4 litres, you don;t have the natural torque that a big cubic motor produces in spades.
If you do a search for Joakims car, there is a print out of the dyno run. Very impressive figures, but absolutely nothing below 4k. And i mean NOTHING. So think about what you want the car for, and be realistic. Having a mad top end rush all wrapped up in a 2K rpm burst is fun, for a week or so. Better spec the motor with a good, responsive turbo, that has boost early on, and gets you down the road. Trust me, 300-320 BHP will make one of these cars fly. Mine is capped at 250 and at a recent track day, there was pretty much bugger all that could touch me.

regards,

Steve
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