13BTOY

iTrader: (1)

Alright guys, I finally completed my SE swap into my GS. Thanks to everyone that helped me get through it. Now I'm just trying to work out the bugs. Timing is set at 0 deg. @ idle for Leading and 20 deg. trailing.
The problem. I get a high rpm miss(pop-pop-pop) usually after about 6200 rpm at full throttle and you can feel the power lost. Other than that the car runs great. Where should I begin?

Thanks, Ed

MarkPerez

I don't know how much you know, but the 13b (-SE) engine uses a larger flow fuel pump for one and check the fuel filter. replace it anyway. the -SE's main fuel (hardline) is larger diameter then a 12a's. could be fuel starved... what about the ECU? -SE's ?

13BTOY

iTrader: (1)

I carbed this motor. I'm running everything that I had on the 12a on it. Dellorto carb, carter psi pump, purolator reg.,4 puc clutch, road race header, 2in straight piping into a fart can and even the dist and direct fire from the 12a. This set up on the 12a revved to 8000 grand no problem! Hold on, I think I might have answered my own question. Everything was swapped over except the plugs. They were in the motor when I got it. Do you think this has anything to do with it? I'll check then out anyways.

Thanks, Ed

heb09

I have the same problem in my 12a bridgeport atm. Tried everything except timing and carb rebuild.

13BTOY

iTrader: (1)

Bump!
Anyone?

ReZ311

iTrader: (4)

I had this problem too. But I run a GSLSE dist in my Turbo II 2nd gen.

I checked everything. Replaced coils, wires, etc....

REPLACE THE CAP N ROTOR! That's the problem! Get the Borg Warner type. The contacts seem to work better.

MarkPerez

when the engine falls on it's face @ hi-rpm's , it's not getting enough fuel.. my -SE was missing @ hi-rpm. i bought new: plugs,cap/rotor/wires/fuel pump/fuel system hi-presure hoses/fuel filter(s) didn't help. went to the junkyard, the mission was find: injectors/fuel presure reg./pulsation dampner.installed these used parts on the engine and now it run just like it used too.
no missing,no falling on it's face. my 12a car (carb.) when ever it starts to miss @ hi-rpm's the first thing i replace is the fuel filter by the fuel pump and every time thats what the problem was. i use 2 fuel filters on both cars. but thats me.

13BTOY

iTrader: (1)

I replaced the pump and plugs and no more miss. Just got tune it now coz power is going flat at 7000rpm. My direct fire is back on and I used a holley blue to insure I have enough fuel. Fuel pressure is @ 5psi via purolator reg. Any ideas? Timing maybe?


Thanks, Ed

dvcn

13BTOY pm'd but I thought I'd reply here.

I know I sound like a broken record (scratched cd?) but you can't leave anything to chance and fine tuning is EVERYTHING. To run a 13 second 1/4 mile with a non-ported 13B in a street driven 1st gen takes a LOT of tuning.

Fuel
--------------------------------------
-6" air horns will probably make the car slower, use the Racing Beat issued ones.
-Run the largest internal volume air filter you can find, not one of those tiny 2" tall ones with the velocity stacks 1/2" away from the lid.
-The Purolator regulator settings DO NOT correspond to psi. You must have a gauge that you can read while driving you car at 7000rpms+ in 3rd gear.
-5psi is too much for the Dellorto, 3-4psi is fine.
-Your accelerator pump mod will not effect performance at 7k rpms. The accelerator pump circuit does not need to be improved, as long as everything is adjusted and functioning it is brutally responsive.

Ignition
-----------------------------------
-mark your pullies and set the total timing to 26* BTC L/16* BTC T
-just use BR9EQ-14's, I just ran a 13.53@102.9 with a really old set. They are fine, cheap and don't foul as easily as the BUR9EQP's.
-Use an MSD 6A for the direct fire along with assemble yourself MSD Superconductor wires.

clutch
------------------------------
-don't use more clutch than you need, it only breaks parts and is much harder to drive. I'm currently running a stock replacement clutch/pp, no slipping and very easy to control engagement while launching.

exhaust
------------------------------
-I think I've run over 20 different configurations of exhaust. Where and how you collect the primaries makes a difference on the powerband. I'm currently running the RB street port exhaust. It is powerful and you will never get in trouble with law enforcement or neighbors. Your 'fart can' muffler may not be as free flowing as the noise makes it appear. Long primaries are the way to go.


Doing these things perfectly will get your car deep into the 14's, possibly the low low 14's. It will take many other small details to make it get into the 13's on a stock, non ported engine.

Use the hp/et calculators. Figure out what you need to do to run the number. Hope this helped.

13BTOY

iTrader: (1)

Thanks for the detailed post. I'll replace those accel pump jets just in case and put my 2in horns back on. For some reason I feel its dumping too much fuel up high because of the modded pump jets. Anyhow, I have always wanted an RB streetport system I gues it's time. Anyone got one for sale? I just need from the header back. The fart can has grown to be very annoying.
Thanks again! I'll post the results here.


Ed

13BTOY

iTrader: (1)

Alright part one of tuning begins. I swapped out the cool looking 6in. air horns for the racing beat issued 2incher and she revs to 8000rpm cleanly, no miss, no hiccup! . I still need to play around with the carb though coz my throttle response is not that impressive and the power is still not there. I'm also in the process of indexing my pulley for proper timing. I think this has something to do it. By the way I ordered that jetting combo yesterday but the sad thing is, its not going out for shipping till early next week. I hate waiting for needed parts!

Later, Ed

dvcn

Sounds great Ed!

Everything does work together, sounds like you are on the right track. Keep at it and keep us updated. I want to see you eventually post some really good 1/4 mi times!

13BTOY

iTrader: (1)

Okay, just got back from a road test. The car is totally different! I dropped fuel press. to 4psi. set timing at 0 for both leading and trailing @ idle(working on indexing my spare pulley), and 2in horns. Overall performance is great but I think I need more fuel up high. In first gear my car felt like it hit a wall right after 8000rpm(monster tach) @ WOT and forced me to shift to second. I did this several times with the same result. Any thoughts? Anyways I did pull my plugs after the run and it was a slight brownish color. YEAH BABY!

Thanks, Ed

heb09

Don't take it over 8000grand, theres no need.

dvcn

When I ran my 13.96@97mph with a stock, non-ported 6 port 13B with the RB Dellorto, MSD, RB exhaust setup, I shifted at 8100-8200rpms for maximum acceleration. Shifting higher or lower made the car go slower. I would have to disagree and say that there is definitely a need.

During autocross runs I ran it well over 9k, upshifting and the subsequent downshift would have cost time.

Ed-
Please set the total timing to the spec that I gave earlier. That may improve your high rpm lack of power. I just noticed that you have both the leading and trailing set at BDC? Why? I forgot if you are running direct fire with an MSD or not. It is worth every cent.

Also, when you are at 8k are you looking at the fuel pressure gauge? You must set the pressure at max load. When it was stumbling what was the pressure at? Also, I run a bypass regulator - Mallory 4309. This is a far superior regulator to any of the non-bypass units. It also has a boost/vacuum reference on the diaphragm which, in the case of an NA, lowers fuel pressure at idle and low load conditions so your needle and seat aren't overwhelmed. There are also multiple ports so that it is easy to hook up a pressure gauge.

13BTOY

iTrader: (1)

Youre right about the direct fire setup. It works great. I'm running a direct fire set as per jeff20B with 3 stock coils and 10mm magancore wires. About the timing. I working on my pulley now. 26 BTDC-Leading and 16 ATDC for Trailing. Right? Is this at 4000 or 6000rpm? I'm having a hard time making the marks though. Every time I run my hacksaw it chips the paint off the pulley and widens the mark. Gotta get a new blade. If theres more power to be had with the @ 26 and 16 thats freakin great! Unfortunately my gauge is teed in the engine bay in between the carb and regulator. I'll rig up something so I can monitor it and maybe when I get some cash just get an outside mount one. I just didnt want to put one out there before because I wasnt making enough power and didnt want to look like a poser. But things are different now! HeeeeHeeeee.....
By the way I will be getting that Mallory regulator because I need it anywas when I boost this motor but thats in the back burner until shes primed and ready. After I hit my 13 sec. goal.


Thanks, Ed

dvcn

The direct fire/stock igniter setup is better than stock. Don't let anyone tell you that the igniter setup is even in the same league (or better.....)as a capacitve discharge ignition like the MSD 6A.

-Stock coil charges at 12V if you are lucky. MSD is somewhere over 460V.

-Stock fires the coil once per strike, if you are lucky. At high rpm there may not be coil saturation which means as rpms go up, spark energy goes down. MSD: It fires multiple sparks ALL the time. I believe it is 6 hits at idle and it was 3 at 8k rpms. I hooked up an osciloscope and also recorded the output off of an inductive pickup to verify this.

-Stock: as system voltage goes down, so does spark energy. MSD: down to 8v or so, it doesn't really care.

I have to say that the MSD is also more reliable than the igniter. I've found handfuls of bad igniters while only 1 out of approx 40 MSD 6's I've been involved with have gone bad.

I've heard some nonsense about the MSD having a time lag. I've never noticed, that is why you set total timing, it is what is real.

Sidenote: For those running the igniter setup, with the ignition on, check the voltage on the + terminal of all your coils. Is it exactly the same as what you see on the + terminal of the battery? If not, you are loosing ignition power. The cure is to run power to the coils via a 30amp relay that is tied directly to the battery.

Timing:
26* BTC Leading, 16* BTC Trailing set at 4k+ rpms. You can see on the timing light where the mechanical advance stops. After you set it rev the engine to 6k just to verify.

Before you do any of this, please understand what total timing, vacuum advance, mechanical advance and all other systems.

You don't have to permanently mount the fuel pressure gauge. You already have a T, just extend the gauge out on a hose and for testing, just use your windshield wiper to hold it down.

13BTOY

iTrader: (1)

Thanks for clearing up the timing. Also I have to try the MSD set up. Theres been so many misconceptions about it ,thats why I went with the proven directfire with the igniters. Plus it cost nothing! I'll keep you posted.

Thanks, Ed

13BTOY

iTrader: (1)

Just purchased a Mallory 3port for tuning flexability just like you recomended but have to wait until it gets here. The good news is my pulley is marked. 26 deg. before Leading TDC and 16 deg. before Trailing TDC. Actually I just finished painting it. This is how I did it. I measured 26 deg. back from the Leading mark and 16 deg back from the Trailing mark. I hope I did this right? It will go on tommorow and I'll set the timing. I'll post the results.

Thanks, Ed

dvcn

Ed-
http://www.yawpower.com/pultime.html

You have to know what the current markings are on your pulley. I can't remember from memory, something like 5 ATC and 20 ATC. IF (please verify this yourself!) this is in fact what your pulley is marked at, then to get marks at 26 BTC and 16 BTC you will have to go 31* from the 5 ATC mark to get 26 BTC. You will have to go 21* from the 5 ATC mark to get 16 BTC.

0 ATC = 0 BTC = TDC
5 ATC = -5 BTC

13BTOY

iTrader: (1)

Damn! I totally forgot about that. I think youre right. The marks on the SE pulley is 5 deg. ATC Leading. I'm not sure about the trailing though. I look into it.

Thanks, Ed

13BTOY

iTrader: (1)

I cant get a straight answer. First off. Do I measure both the L and T from the stock leading mark? Or measure leading from the stock leading mark and trailing from the stock trailing mark? I measured the difference between the 2 stock L and T marks and it was 15mm should be 15 deg right but I just read Paul yaws article and he mentioned that the trailing is 20 deg away from the leading. I'm lost!

Thanks, Ed

dvcn

Sorry for the confusion. You probably know most of this but I thought I would try to be more concise, I dont' mean to insult anyone.

-Yaw's article applies mostly to 12A's. The 13B has slightly different timing.

-The 84-85 13B stock timing marks are:
5 ATC Leading
20 ATC Trailing

(the 12A is 0 Leading, 20 ATC Trailing)


-Looking at the pulley from the front of the car and with the marks rotated to the top of the pulley, the trailing mark is to the left, the leading mark is to the right. The pulley rotates clockwise. The new marks you are going to make are to the right of the stock ones (I admit that I've accidentally flipped the pulley over when marking it and have had to re-do it. I now just mark it on the car)

-If think this is where I confused you, it doesn't matter where you reference your measurment from, it can be from the stock leading mark or the stock trailing mark.

If you go 31 degrees clockwise from 5 ATC, it will get you to 26 BTC.

If you go 46 degrees clockwise from 20 ATC, it will get you to the same 26 BTC.

In a nutshell, you are correct having that 15 degree split on the pulley (the 12A is 20 degrees). That is the correct split on the stock 84-85 pulley.

13BTOY

iTrader: (1)

Thanks! I'll reference from the Leading mark and measure out 31deg. to get the 26deg for the leading and for the trailing should I measure out 21deg from the stock leading mark also so I can get the 16deg for trailing. Sorry if this sounds repetitive but I want to make sure I do it right. Because my first run it at it was all wrong. I measured out 26deg. from the stock leading mark(reference point) and 16deg. for the trailing. The car would not rev and wanted to stall. It would hesitate real bad and then the revs would go up. l didnt even bother taking out for a test drive. This was at idle. Did that setting give me 21 Leading and 11 trailing. Please let me know if I'm understanding this correctly.



Thanks, Ed
I hope you guys are taking notes!
By the way the regulator I won from ebay was the wrong one(no vac nipple) so back to square one. Bummer!

dvcn

Your math looks good! Just make sure you set it at 4k rpms +. After you lock everything down, check it again up to 6k rpms.

The next best place to get the regulator is Summit Racing, $74.88.
http://store.summitracing.com/partde...art=MAA%2D4309