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The realities, do's and dont's of boosting a 1985 928 5SPD

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Old 03-17-2017, 09:19 AM   #16
John Speake

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Exactly... the early 32v in fact can accept 5-6lb of boost without any real modifications of the ignition timing.

The reason is that Porsche gave the 84-86 cars very safe timing to take account of the variability of fuel available at that time. It is this margin which has been exploited by Ken (US 32v 85/86) and also by me (84-86 16v Euro) and this unlocks quite a bit of extra power for those (unboosted) engines.

I don't know how much boost Charles intends to give his engine, but if going above 6psi I would say a knock control system such as the Vampire is an essential.

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Originally Posted by The Forgotten On View Post
^^ I guess the lh2.3 uses the knock sensors instead of this temp sensor to retard or advance timing. Thank you.
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Old 03-17-2017, 09:37 AM   #17
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Quote:
Originally Posted by John Speake View Post
Exactly... the early 32v in fact can accept 5-6lb of boost without any real modifications of the ignition timing.

The reason is that Porsche gave the 84-86 cars very safe timing to take account of the variability of fuel available at that time. It is this margin which has been exploited by Ken (US 32v 85/86) and also by me (84-86 16v Euro) and this unlocks quite a bit of extra power for those (unboosted) engines.

I don't know how much boost Charles intends to give his engine, but if going above 6psi I would say a knock control system such as the Vampire is an essential.
Thanks for all the information.

I'm shooting for 10 eventually, but I'm starting low at 5-7 range. Is this vampire you speak of ? http://www.jandssafeguard.com/VampirePage/Vampire.html If I go the vampire route would I still need your ST kit?

Last edited by cpayne; 03-17-2017 at 10:00 AM.
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Old 03-17-2017, 12:11 PM   #18
John Speake

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Yes, that's the system. There's a couple of people here who have used it, for example Andrew Olson on his twin screw 85/86 car.

That system would be your safety net. I can provide you with a EZ-F starter chip designed to suit 10psi. That combined with the Vampire would keep you out of big trouble, but to fine tune the system you would need a Sharktuner.

I was ill for a week so have been catching up working on the pile of boxes in my office. I haven't forgotten your enquiry.
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Old 03-17-2017, 12:37 PM   #19
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I have a 2.5 bar MAP sensor installed in my EZF which will allow me to tune the ignition curve based on actual boost, not just RPM and MAF load.
This isn't necessary, just something we wanted to play with since the 85/86 US and 84/85 EuroS ignition brains have MAP sensors.

Unfortunately the car was parked just as I was getting this setup tuned and as life goes on, I haven't picked it back up yet.
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Old 03-17-2017, 01:26 PM   #20
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Quote:
Originally Posted by John Speake View Post
Yes, that's the system. There's a couple of people here who have used it, for example Andrew Olson on his twin screw 85/86 car.

That system would be your safety net. I can provide you with a EZ-F starter chip designed to suit 10psi. That combined with the Vampire would keep you out of big trouble, but to fine tune the system you would need a Sharktuner.

I was ill for a week so have been catching up working on the pile of boxes in my office. I haven't forgotten your inquiry.
I'll order the J$S unti I assume the one for the distributor and the knock sensor. I'll also get one of the temp sensors you mentioned and since I'll need a shark tuner when you get caught up we can proceed.
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Old 03-17-2017, 02:27 PM   #21
John Speake

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I would advise to talk to others who have used the Vampire on 85/86 boosted cars.... first.
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Rebuilt LH, EZK ECUs & MAFs available from agents worldwide.
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Old 03-17-2017, 08:46 PM   #22
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Google drive link to the Turbo design and MAF harness documents in post 1 for those who have expressed interest.

https://drive.google.com/open?id=0B-...zJZbFVMWVZoLXc
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Old 03-19-2017, 12:31 AM   #23
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Installed the new scavenge pump today and started cleaning up some from the electrical . The aluminum pump mount plate was a nice attempt, but had burrs on it. Filed the burrs off . It was mounted to a hole drilled in the chassis with a hardened steel bolt and no nut. Vibration over time would surly bugger the aluminum threads in the bracket mount point. To mitigate this risk we put a nylock on the bolt to hold the mount in place, so if the aluminum threads do degrade the unit will stay on the car.

Apples to Oranges when comparing the replacement pump I bought versus the one supplied with the turbo.







Old pumps wiring.


New pumps wiring.








This is how I found the wiring in the battery box. Notice the Red wire from the old pump and the White wire (not sure what that one is for yet) with electrical tape to aide in resisting damage from where they enter.



Added some Gold plated terminals. I Have some more zip tying to do and will mount the relay in the battery box. Added grommet for the new pumps wiring. I'll be rerouting the white wire back through the grommets to avoid the battery box lid from resting on it.



Drilled a small hole for the white wire and put rubber grommet on it fed it out the grommet and back into the battery box grommet I put in yesterday. tidied the wiring up a bit more. Is there a battery brace part number? as the PO used 2 2x4s to keep the battery from moving around.


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Old 03-19-2017, 06:51 PM   #24
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Scavenge pump comparison.

Original pump less than 25 miles from since I got the car home. Probably 100 miles total. Listen for the annoying whining of the original scavenge pump.



New pump


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Old 03-20-2017, 12:38 PM   #25
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Dang brother, you've had a lot of clean-up to do. It's coming along.
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Old 03-20-2017, 01:26 PM   #26
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Quote:
Originally Posted by Chris Lockhart View Post
Dang brother, you've had a lot of clean-up to do. It's coming along.
You got that right. Lots to do.
I'm moving the MAF back to the its original spot and putting in the chipset later this week. I'm waiting on an 87 FPR as it is supposed to push the necessary fuel for 30LB injectors.
I'm also on the hunt for an appropriate inter cooler. I reached out to Mr. Kuhn to see if his rig would work with my single turbo.
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Old 03-23-2017, 12:21 PM   #27
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Quote:
Originally Posted by John Speake View Post
I would advise to talk to others who have used the Vampire on 85/86 boosted cars.... first.
I spoke with Andrew O. John and he never had a Vampire, just a Knock light device.

In reading the online manual for the Vampire, looks like you can use a two coil feed setting/input and then set the box to retard all 8 ( by affecting both coils ) once knock is detected.

A bit pricey, but would be easy to go back to stock, works with N2O too

Dave
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Old 03-23-2017, 12:31 PM   #28
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Does the Vampire only work on 85/86, or all 32 valve models? How much was it Dave? I couldn't find any pricing info, short of emailing for a quote.
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Old 03-23-2017, 01:15 PM   #29
John Speake

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Maybe start a new thread about the Vampire.
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SharkTuned LH & EZ-F

www.jdsporsche.com
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Rebuilt LH, EZK ECUs & MAFs available from agents worldwide.
USA agent for LH and MAF checking and repair is Louie Ott :-
http://www.performance928.com
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Old 03-23-2017, 02:10 PM   #30
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Quote:
Originally Posted by Chris Lockhart View Post
Does the Vampire only work on 85/86, or all 32 valve models? How much was it Dave? I couldn't find any pricing info, short of emailing for a quote.
PM sent
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