Dizzy recurve question

[Reiver]

I've a stock euro '83 SC w/ SSI's/dansk pea shooter....I've lightened the car considerably and use it as a street car. The 930-10 is pretty fresh and spirited with the 9.8-1 comp, larger intakes, wur controlled AFR.
I've heard that recurving my dizzy is a better focal point than adding dif cams if I want to retain the midrange torque sweet spot.

Question, is that a good assumption?

Does the recurve just bring in the advance sooner/quicker?

Who would you recommend for the work/recurve/rebuild?

[ClickClickBoom]

I had Jerry Woods recurve/rebuild my '74 dizzy. He asked a bunch of questions on intake and exhaust, planned usage along with fuel type. Popped it back into the car and it was a very nice change, much better throttle response and drivability. Any good distributor guy can do the same, plenty listed on the forums. I went to JWE because he was close and I could see the cool stuff in his shop.

[Reiver]

Originally Posted by ClickClickBoom

I had Jerry Woods recurve/rebuild my '74 dizzy. He asked a bunch of questions on intake and exhaust, planned usage along with fuel type. Popped it back into the car and it was a very nice change, much better throttle response and drivability. Any good distributor guy can do the same, plenty listed on the forums. I went to JWE because he was close and I could see the cool stuff in his shop.

Jerry is a well respected name in the Porsche field so I'd be willing to go that route.
What was the time turn around on that?

[ClickClickBoom]

Jerry Woods dizzy install!
Week or two, I forget.

[James Brown]

did mine and it really woke it up, 32˚ total advance at 3500 rpm. wow kicks butt! and there mechanical, no vacuum pot or hose. I think the best bang for the buck.

[juanbenae]

it will likely be less effective if the CIS injection system remains in place. if you've gone to carbs the improvement will be noticeable and is a must do. the VA is best left in place for a road going car daily driver with CIS or carbs due to the best timing throughout the range. but then again will give you a thrill on a long twisty road when yur right foot is extended.


you don't say where your at, so if shipping your part away for the work look for something reputable, and close. if you do chose JWE for the recurve,, tell rich juan benae sent ya. no guarantee you will be served faster as they are slammed about now, but sure to put you in the good graces with a chuckle....


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[Joe Bob]

Sorry to hijack but.....does a chipped 3.6 benefit from a re-curve?

[jbell959]

Aaron Burnham

Burnham Performance
1071 Avenida Acaso, Suite D, Camarillo, CA 93012 (805)240-6931

[snbush67]

Reiver, unless you know what your curve is now than you are going in blind. If your distributor is old and worn out than you don't know if it's going full advance, getting hung up or advancing slowly etc.

Use a timing light to determine if your distributor is operating correctly. You aren't going to feel a lot of top end gain simply from going all in at 3k, it's just not going to help, rather you will benifit more from a smooth idle and drivability from a properly set and operating ignition.

A simple cleaning and some lube is likely going to perform as well as a rebuild and "recurve".

If you have a timing light you can check your advance as well as anyone else, and you have the added benifit of checking it in your own car.

I am a bit hypocritical as I have a locked out distributed with a msd programmable ignition, so I can have any curve I want. I wrote a thread about it.

MSD 6AL-2 Digital Programable Install and Distributor Lockout

[James Brown]

Originally Posted by Joe Bob

Sorry to hijack but.....does a chipped 3.6 benefit from a re-curve?

no its all in that moronic do hicky, the dissy innards do not move, the computer handles all that. you can have a tuner change some parameters (big word)

[patz]

What is involved? Surgery on the DME?

[E Sully]

Originally Posted by patz

What is involved? Surgery on the DME?

It involves changing out the chip inside the DME. Early ones can also be modified to accept later chips.
There are a few different chip programmers. They can make chips to work with stock, engine and cam mods, and fuel octane. If you search the forum you will find a few threads, and occasionally the aftermarket chips are listed for sale in the Parts Forum.
The stock distributor does need to be checked for play in the shaft, and that the weights are moving freely for correct positioning as the timing changes.

[MattTHEpainter]

Barry Hershon - Eccentric, but he knows his stuff and cares. Prepare to be inundated with knowledge at all hours of the day. Called me a few times about a month after he finished my dizzy to check on it. Awesome job, but not cheap. IAE Inc.

[patz]

Originally Posted by E Sully

It involves changing out the chip inside the DME. Early ones can also be modified to accept later chips.
There are a few different chip programmers. They can make chips to work with stock, engine and cam mods, and fuel octane. If you search the forum you will find a few threads, and occasionally the aftermarket chips are listed for sale in the Parts Forum.
The stock distributor does need to be checked for play in the shaft, and that the weights are moving freely for correct positioning as the timing changes.

So I need to speak with Steve Wong. I'm guessing it has already been tweaked to optimum output or as far as he will get with his chip and not get sued for blowing up the engine.

Anyways, Wihoit Restoration has a dyno day at their open house on the 5th. Will see what I get.

[snbush67]

This is part one of how to lock out your dizzy;

DIY -- Distributor Vacuum Pod Delete and Vacuum Lockout

[Jonny H]

Originally Posted by Reiver

I've a stock euro '83 SC w/ SSI's/dansk pea shooter....I've lightened the car considerably and use it as a street car. The 930-10 is pretty fresh and spirited with the 9.8-1 comp, larger intakes, wur controlled AFR.
I've heard that recurving my dizzy is a better focal point than adding dif cams if I want to retain the midrange torque sweet spot.

Question, is that a good assumption?

Does the recurve just bring in the advance sooner/quicker?

Who would you recommend for the work/recurve/rebuild?

SC's definitely benefit from some timing advance, particularly with modern fuel (it burns slower so we need to ignite it sooner) and the CIS can cope with being richened a little to complement. Go and try it. Advance the distrbutor a few degrees (dizzy clockwise) and tweak the fuel a notch or too richer.

A traditional recurve would probably throw the weights out sooner but I'm not sure if they can extend the range of the advance beyond the stock 20 degrees of movement. As another person said above, the problem is knowing what to ask for.

A more flexible approach would be to adopt an electronically timed ignition and lock the weights entirely. This not only saves on the cost of the recurve, but also negates a distrbutor stripdown and rebuild. You can then play with the timing as you see fit but a rolling road session is advisable to get the best setup.

My 204hp 82 SC runs SSIs and 964 cams with the standard CIS and definitely benefits from ignition advance.

Of course, I would say that since my company sells such an ignition product which comes with a unique locking device for the SC distributor which can be fitted in minutes! The whole system is plug and play with original looks too.

[snbush67]

Originally Posted by Jonny H

I would say that since my company sells such an ignition product which comes with a unique locking device for the SC distributor which can be fitted in minutes!

Hi Jonny,

I looked at your website but couldn't locate the referenced "Unique Locking Device" do you have any more information and pricing?

Thanks, Shane

[Jonny H]

It's on page 29 of the manual, here

CDI+ Manual

Pricing and general info:

Pricing

[snbush67]

Thanks! That is a bit easier than my method of locking out the weights with an adaptor.

Were you able to check the spark placement to eliminate rotor phasing issues?

[snbush67]

I also like the overlay ability of your unit, My MSD doesn't recommend that as an option, I don't know why?

Your CDI+ manual does a great job of explaining everything, I had to figure out that stuff on my own when I installed my MSD.