Nice and tidy.... good job!

Where did you mount your MAP? How far away from the vacuum manifold is it?

You may wish to consider placing the relay board into an enclosure. It's hard to tell from the photo, but it doesn't appear to be NEMA 4 rated?

Good luck with the tuning.

Trog

sweeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeet man...
How does it run and any comparison comments vs previous set up(s) you have experience with ??

Great job...I have been following this since the begining & glad it is turning out so well......

Bob

sub'd

Thanks Trog. You were an inspiration. I looked at yours many times when I had questions.

The MAP is built into the ECU. It is mounted under the passenger seat. I used a 10 foot section of premium hose, think it was Goodyear for that. I used the Porsche correct cloth stuff in the engine bay.

According the the site I bought the relay board from (DIYAutoTune.com), it is rated for under the hood use. Is there a way to tell?

It was previously a stock CIS setup with SSI, Backdated exhaust, MSD, and Magnacores.
It didnt run bad. It actually ran good... fine on cold start. great warm. Just didnt have the throttle response I was looking for.
I made two changes.
1. Rebuild and recurve the distributor, delete the vacuum advance. Delete the vacuum retard. Full advance at 3k RPM's. Also when rebuilt had 35 degrees of total curve inside the distributor.
As luck would have it, I installed this with the CIS still in the car. Wow. it was like a new car. I must have had advance that wasnt working, but this woke my car up.
2. EFI / ITB's. If I had done this first I might have noticed a big difference, but with the new dizzy, i must say that I didnt see a huge gain with this across the power band. there was noticeable improvements in throttle response. It pulls harder in the beginning. Pulls harder at redline. But there is little gain that I noticed from 2750-5500 rpms where the CIS really shines.
I will say that it probably allows the full capacity of the dizzy to be realized...

I also think that with tuning you can get a more smooth throttle. with less lean spots and less rich spots and more consistency.

I think that this was a great project. alot of learning. if you spend the 4k on the ITB's, spend the 500 on the dizzy. you will be leaving most of your power on the table if you are using a stock SC dizzy... I think alot of guys do one or the other and probably feel a difference... but the real improvement is doing them together.

hope this helps...

I'm confident your relay board is rated for the range of temperatures one can expect under the hood, however with exposed terminals and components, it may not survive a wash-down. Take precautions.

Generally, the MAP should be located as close to the vacuum souce as possible. You may experience odd behavior during your tuning efforts.

T...

Actually Trog, We did a test of the vacuum hose length vs. loss and found very little difference in the map sensor reading. Going from 50 ft. (the whole spool) to 8 ft. made just slightly a time and pressure difference. Not enough to make a difference for the sensor used in the MS units.

Believe me I thought the same thing when I was having my initial problems. So we came up with this as a test.

I have had no issues.

I used about 8 feet of a 10 foot section.

I havent had an issue either going from under the pass. seat to the manifold.

We run about 3.5 feet to our ECU (MAP built in) and have no difference in vacuum or response compared to taking a reading right at the vacuum manifold.

Cheers

Pressure waves travel at essentially the speed of sound. After all, sound is just a vibrating pressure wave. Since air has very little mass there is no inertia. No mass, No inertia, no time lag. I don't think you would see much of a difference in pressure reading through at least 100 feet. Even then the pressure would be accurate yet the time resolution would be slow - yet still fast enough for the ECU to respond to the engine.

You could mount the ECU in the front trunk and still have an accurate reading.

I think its a non-issue in the Pcar. Its such a small distance. I have never read of anyone on the board who did an efi install and who mounted their ECU under the seat and the Vaccuum where it is that had an issue. Most of these ECU's are coming with an Map inside the ECU and most are not mounting it in the engine bay due to heat... In fact everyone told me not to put it in the engine bay or rear shelf... Just my .02. I have no proof, but I have had no issues.

Great project!

If I many, are you saying the dist has 35 deg of mechanical advance?

Thus, are you setting timing at zero at idle and it runs at 35 deg at 3000rpm an behond?

Or is is something like 25 deg of mechanical advance and you set it at say -10 at idle and hit -35 at 3k rpm?

Thanks in advance.

Sorry. Just saw this.

I have it set at -5 degrees at idle and 32 degrees at 3 k rpms. So I have about 37 degrees inside the distributor.

The stock 83SC distributor has 10 degrees of mechanical advance in the distributor. Distributor spec are expressed in distributor machine degrees (half of crank), timing specs are crank degrees. The timing spec is 5 BTDC (crank) and the distributor advance adds 20 (crank) for a max of 25 BTDC (crank). If you modify the distributor to give 32 BTDC max at the same static, the advance inside the distributor would be 13.5.

Ummm ok Paul. I have a dial type timing light... I set it at 5 BTDC at idle. I set it at 32 degrees of advance at 3k RPM. I dont really need to say more than that. I have 32 degrees of advance. Whether its really 13.5 inside is immaterial. Car drives like a dream and did so even with the CIS with the advance set like I have it... If you call Jerry Woods or Barry Hershon, who are expert at distriubutors, they will tell you the above scenario means you have 37 degrees of movement inside the distributor. Who am I to argue with them. Whether its really 37 degrees... well most of us arent really needing to know that information... because we are sending it out to them... We just tell them the degrees of advance that we want at both idle and 3k RPM, and they figure it out...

If your max advance is 32 BTDC and your static is 5 BTDC, the mechanical advance is adding 27, not 37.

Point one, you are arguing with Barry Hershon who has recurved more distributors in the last 10 years than you will see in two lifetimes.. Point two, is that I really dont care. I set my advance to 32 or 33 degrees at 3k rpm and i have a car was was awakened.

Brad,
Did you ever dyno?
How did the ITBs effect area under your power curve?

Doug