Supertec is building us a turbo motor!

[Lensart]

We're thinking about twin plugs and this XDi Dual Plug Ignition Kit. (http://www.clewett.com/) What do you guys think?
Thanks, Randy

[KobaltBlau]

I think that kit is probably the best way to do it unless you want to go to full engine management (EFI+electrontically controlled ignition) and even then I would use the clewett parts for the pulley/sensor arragement

[MotoSook]

How come Henry hasn't chimed in? He's usually pretty active on this forum.

[KobaltBlau]

I think he's more active when he's less busy, perhaps. His activity seems to go in waves

[Lensart]

Henry is going to post pics when he gets started on our engine. We are still gathering parts. If there is any interest I've started a topic on my weekend demo in the 911 tech forum. (Not for the faint of heart...)

[briankeithsmith]

That is what I did on my car. I bought all of my stuff at Clewett, even his terminated wiring harness (which makes it very easy). I went TEC3 though. not just ignition, but fuel injection also.

Clewett is an excellent source for that stuff.

Brian

[beepbeep]

Originally posted by Lensart
We're thinking about twin plugs and this XDi Dual Plug Ignition Kit. (http://www.clewett.com/) What do you guys think?
Thanks, Randy
http://forums.pelicanparts.com/uploads3/xdi+kit1097616030.jpg

I think it should be easier/cheaper to use EFI with united ignition module than to try to marry two systems together. Less cables, less boxes, less things that can go wrong.

SDS is cheap and has both ignition and fuel part, so does Haltech and Autronic. Autronic is little more expensive but there are lot's of shops that have expirience mapping those.

[briankeithsmith]

Goran:

I didn't want to say it but it would seem to me that if you pay the money now to go with XDI, then you've bought half of the EFI system already, so why not just buy the whole thing and make the switch?

Everyone bashes Electromotive it seems but mine seems to work very well, and I haven't had any issues yet with their product. The tunability is nice, not as detailed as Motec, but then again Motec is about 50% more in price so you get what you pay for.

Brian

[Lensart]

Everything is a tradeoff. If we spend too much on the engine we can't finish the car the way we want. The twin plug XDI option is not that much more then a dist. and MSD w/retard and rev limiter. Plu I like crank trigger ign's. We will get used to this amount of HP after the racing season and want more HP and we'll sell this and build a EFI engine.
Thanks for your help, Randy

[briankeithsmith]

Randy:

I understand that point of view as well...

Brian

[beepbeep]

Hmm, so you are planing to keep CIS? I didn't understand that until now. I believed all this time that you were to use EFI.

Unfortunately, I find decision to keep CIS very unwise. CIS is one of first things to ditch when tuning 930 motors. All this talk about picking state of the art turbochargers and well-formed headers goes trough the window if you attach it to CIS.

I find your build budget somewhat skewed in that case. Trying to get more power from CIS is flogging the dead horse. It won't flow much more than 400 - 450hp no matter what you do. Porsche knew this all the time and build dual parallel K-Jet systems in their 934's in order to get them to breathe easier, and they didn't get so impressive power anyway. (They had to retain same fuel injection as in production cars for homologation reasons) It's not it's ability to provide fuel that is limiting, it's its construction. Airflow-measuring barn door will be there no matter what.

More or less stock 930 engine will provide 400hp all day long with modern (but not state-of-the-art) turbo and EFI. You went the other way and specced whiz-bang engine with costly parts but somehow decided not to correct this inherent 930 weakness.

With other words, you can probably achieve same HP goal with (considerably) less money if you start with EFI first. I believe that single-plugged 3.3L engine with K27- turbo and EFI will dyno as much power as your 3.4L dual-plugged GT35 mill with costly headers and CIS.

You have specced impressive mechanical base to build on, I suggest that you try to save some money on turbo-choice to begin with and use that to try to convert the engine to EFI+computerized ignition from first begining.

Decent EFI like SDS will cost around 1000$, including injectors, MAP-sensors, direct-fire coils and whole sheebang. Otherwise it would be such pity to build a monster engine just to choke it with such substandard fuel system. I would rather save some money on turbo side in order to convert it than go for best turbo and keeping the CIS.

I understand you allready bought the ingition parts, so it's nothing to argue about. I'm just saying that EFI will make a huge difference performance and performance per dollar-wise, proportionally bigger than other trick parts you have in your engine.

Cheers!

[briankeithsmith]

Well said.

My EFI conversion dynoed at 431 RWHP, and the tuner said that with some additional tuning I could get maybe another 20 RWHP out of it. But I wanted to stay kind of conservative on some of the settings.

430 is not bad, thats about 480 or so at the flywheel.

If you have the spare change to convert to EFI, it is worth it. Plus, nothing beats being able to hook up the laptop and see exactly what is going on with the engine.

Brian

[Porschekid962]

This is interesting because my dad and I are still trying to figure out which EFI system to use on his motor that we are building. After talking to Steve Weiner at the GAF I realized there are some pretty attractice EFI setups aside from the Electromotive. I am thinking of using the DTA ecu with VW VR6 coilpacks. If anyone say his ITB setup at the GAF you know his stuff is first class just like Henry's. Just a different way of doing the same thing.

[Lensart]

"More or less stock 930 engine will provide 400hp all day long with modern (but not state-of-the-art) turbo and EFI. You went the other way and specced whiz-bang engine with costly parts but somehow decided not to correct this inherent 930 weakness."
Well, it's not quite that simple. We talked to five well known builders about CIS and EFI motors, always $5000 to $8000 more for the same engine with EFI. The bottom end, heads, cams, etc. of this engine would have cost the same. I asked for an engine that would be capable of 600 hp ( after we change to EFI) and stay together at the race track for at least one season before refreshing.

"With other words, you can probably achieve same HP goal with (considerably) less money if you start with EFI first. I believe that single-plugged 3.3L engine with K27- turbo and EFI will dyno as much power as your 3.4L dual-plugged GT35 mill with costly headers and CIS."

We did not have a core, so we have to buy exhaust, turbo, ignition, etc. anyway. For example the cost difference between stock ignition (w/ msd extras) and the crank trigger setup will be around $800 and should give us a greater margin of safety from detonation. As far as the turbo goes, I stared out in this topic asking for help choosing a turbo for a 400-450 hp cis engine and you helped me with the turbo choice, however I have not bought a turbo yet. I have not found a huge price difference in the k27 hybrids and the Garretts ( if one is $500 more but will work a lot better across the range thats fine). If you think a different turbo would work better now that you know more about our engine, I would welcome your advice!

We are trying to build a race car that will win at our local track, hp is about equal on our list with suspension, weight reduction, and brakes.

Thanks Randy

[Porschekid962]

On the turbo note, many of my friends have turbo'd imports and they all run Garrets with great success. My friends single turbo supra has a T3/T4 hybrid or is it T304, not sure, it has ceramic ball bearings and it has lasted him 4 years of running at the strip with insanely high boost. I have gathered from conversations with these guys that if your going to go turbo, the garret's are the only way to go.

That being said, I am sure the KKK's are still nice units but the garret's seem to take plenty of abuse and last a very long time.

[WydRyd]

The KKK or Garrett's can be very reliable turbo's if they are setup properly on the engine with sufficient oil lubrication and drainage. If you are to remain with CIS, the the KKK is the better option as these are mapped for best response with the CIS Injection. If you go EFI, then Garrett is hard to beat.

I've also heard very good things about Turbonetics and Precision Turbo & Eng turbochargers. All of which are built using Garrett technology. The PTE turbo's have more efficient, up-to-date compressors and the maps for these are proprietary (thank Garrett for that!)

[beepbeep]

I believe Garrett's are still superior to those old KKK designs. There is nothing "CIS-mapped" about KKK's. They just pump air and have to spin as soon as possible and pump air w so few losses as possible. A modern Garrett will work well on CIS engine too, it's just that it won't be able to provide it's full potential.

5000-8000$ extra for EFI? Jeez...I bet that's good old "Porsche tax" showing it's ugly head.

If you are somewhat mechanically inclined you could try to do it yourself, using Carrera intake that already has injector bungs and fuel rails. Your heads are already portade on intake side so they whould mach well with bigger Carrera-intake ports.

Problem with 930 intake is that it's just so damn lousy made. It flows unequal amounts of air to different cylinders and is quite restrictive. It's a pity thay you are forced to cut intecooler plumbing to fit 930 intake and then cut it again to fit EFI intake when you are ready to go for EFI.

Good luck!

[WydRyd]

Curious beepbeep, how easy do you think it would be to splice an aftermarket EMS's loom into the OEM Motronic Loom, to retain all the OEM wiring and sensors?

I know the TPS sensor would have to be replaced and a vacuum line run to the EMS for the MAP sensor, but what about everything else?

Would be much easier to just splice into the right connections and use the existing, neat OEM harness/loom

[Lensart]

I've already found a used Carrera intake, and Richard Clewett will take my ign. box in on trade for the EFI setup, it may have to wait until next winter, as we have plenty to do in 4 months.
Thanks, Randy

[1fastredsc]

Not to intrude on your thread, but would you mind listing the website for the SDS efi beep?