gbayfisher

Hi everyone,

I have had a good time reading the threads and stories about the boosted builds here, learning a lot, and getting the itch.... it has been a good while since I have done anything major to the car, and I'm getting bored, so I think I'm going to boost the sbc and have some fun, and I am looking for some advice during the planning and building stage. This will be going forward in the next few weeks if all goes well!

Some may remember the build a few years ago. Here is the link to the thread if anyone is interested in the progression of the actual build.

https://www.thirdgen.org/forums/engi...195-383-a.html

To sum it up, its nothing major and is just a typical forged stroker build, a bit on the mild side, and I do think back wishing I had gone a slightly different route, but It is what it is now and the engine is holding up very well to a few years of street and strip fun, and I think it still has some life left in it, so its time to boost.

The car dyno'd on a mustang unit at 320rwhp through the automatic, haven't had it on the dyno since. Has run a best of 12.7 at 110mph(auto) and 12.7 110 (stick) . Launching with the t56 on Et Streets is no easy feat, and I couldn't get any better than 2.0 60ft, while the auto got me there in 1.75 every time. I have since added SW long tubes which I feel free-d up a few ponies and I will confirm it with a few pulls on the dyno this week.

Getting on to the nitty gritty , and some issues that concern me. First, a few specs:

383
comp 10.17:1
195 afr 195 75cc milled .0300 (prob about 70cc now)
228/228@.50" LC 112
FIRST long tube intake
EBL ecm
42lbs injectors
stock distributor
t56
SW long tubes
3.73 diff ratio
forged bottom

Concerns
1.
Higher than ideal compression ratio. Should I consider removing the heads and installing a boost ready, and thicker gasket? Also good time to inspect the piston tops after years of novice tuning and fun. I can drop the comp ratio to about 9.73:1 with a .060 gasket.
My cranking compression is also on the high side @ 195psi, dynamic compression seems high as well at 9.21:1.
I have considered retarding the cam a couple degrees to try and bleed of some the pressure, would this be a wise move?

2:
Timing issues. Ever since installing the engine in my car, I haven't been able to get the engine to take anymore than 26-27 degrees of advance. Stranger thing is... on the engine stand/dyno at build time , with a victor junior/carb set up, the engine took a full 32 degrees, drop the FIRST on it and efi, and it wont take more than 27. Perhaps I'm dumb and cant install the dizzy in the proper location? I have had it out and in on 5 separate occasions with the same results. I am more inclined to blame the intake for some odd reason...... Thoughts? Could be another good reason to retard the cam or go for a completely new grind? idk.

I have considered this single plane intake with an elbow and LS style TB.

http://www.promracing.com/parts-acce...-manifold.html

Not sure if its worth the work considering I am boosting anyway, but I do have to figure something out to control this timing/compression issue. Not sure the best approach for that, and what I should look for to be causing the problem?

As far as the supercharger goes , I have one lined up already, just a matter of pulling the trigger, just based on reviews and what I have seen and read, the Procharger is going to be the best one for me, Its the only brand with brackets and braces readily available, and I don't have time or machinery to fab one up, I need it to be install ready. going with a D1SC and just the 8 rib (due to clearance issues) system for now and see how it goes.

I am trying for 6-8 psi of boost, can I do it??

Anything advice that would benefit this build would be appreciated.

Thanks






__________________

Orr89RocZ

iTrader: (20)

Throw the thicker gasket on and it will handle 6-8 psi. Just pull timing, back it off alot at first and creep up on it

Verify with a light ur chip tune matches what you see at the balancer. Run a 7 heat range plug

Afr are sensitive on timing. I'd start with 12 deg out on 6 psi to be safe

Bullydawg

iTrader: (7)

Keep the First intake! I will be doing a similar build to your car, but using a superram to keep it California legal. I have a P1SC waiting to install.

gbayfisher

What would be a safe thickness too run on this application? I see that Cometic makes a wide range. Can I go .075 thick? Reduce the compression even more.
Timing light verified dozens of times to be exactly what's on the tune.


Look forward to seeing the build, and good luck.
You collect your parts yet? One of the main reasons for considering a new intake is because I hate the TB on the FIRST, so I might just look in to making an adapter plate so I can replace it with a tpi unit of some sort.

Orr89RocZ

iTrader: (20)

I wouldnt put a mls thicker than .060 on it.

Bullydawg

iTrader: (7)

I have everything but the AFR Heads... My superram is ported, and intake is welded/ported to a 1206 gasket. The P1SC is sitting in a box next to my car. I have been overseas the last 5 year, but will be finally moving back in May. Happy to finally get the chance to make some progess!

gbayfisher

How much boost are you going to run, and how are you control timing and fuel?

Bullydawg

iTrader: (7)

To control timing and fuel, I swapped to an EBL Flash P4 ECU. I am in California, so I am limited to what parts I can legally use, and the EBL still shows factory codes and everything. I would like to run 12lbs... but I think I will just have to see how much I can get away with before I run into the belt slipping.


What supercharger are you planning to run? I might buy a F1A, but I would have to switch to forged internals. I would have to keep the P1SC for smog purposes though...

gbayfisher

[QUOTE=Bullydawg;6028498]To control timing and fuel, I swapped to an EBL Flash P4 ECU. I am in California, so I am limited to what parts I can legally use, and the EBL still shows factory codes and everything. I would like to run 12lbs... but I think I will just have to see how much I can get away with before I run into the belt slipping.


Going to be stout! How much compression are you going to be running?

gbayfisher

oops, double post.

Bullydawg

iTrader: (7)

In the 10's with this current shortblock. I will go lower when I build a new engine.

gbayfisher

Are you going to run water/meth on this current set up? I think I will need it on mine.

Received all the brackets and the head unit, so I can move on to the install, but I am now dealing with a clutch issue. Thought I would get ahead of the game and install the Centerforce DFX I had on the shelve to replace the centerforce DF, Now I have little to no disengagement, and need to figure this one out before moving on.......

no new tires

sub-

anesthes

iTrader: (12)

Your cam is way too small for that static compression ratio, which is why you can't run too much advance.

A single plane with an elbow, a miniram, etc would be a fine choice for a blown application. You'll pick up 50+hp just by losing that intake. I picked up 10mph in the 1/4 in back to back testing.


As far as running a blower, you need to get that compression down to around 9:1.

If someone tells you that you will be fine, make sure they are willing to buy you a new motor when you detonate.

-- Joe

someone972

iTrader: (2)

Dibs on the FIRST if you get rid of it. Interesting thread, sub'd.

gbayfisher

Thanks for the input Joe.

I was afraid that my cam was too small since day one. I can drop compression down to 9.7 with a head gasket change, my heads are milled 75 cc, so I'm stuck, and cant bring it down any further without a piston swap. Do you not think closing the intake valve later by retarding the cam would be enough to bleed off some compression to make it safer? I am also considering meth/water inj, as well as a intercooler. I was really hoping to get something working here without puling the engine apart.

As for the intake, definitely agree that a single plane would work great on this combo, and would free up some space, but was planning that swap for stage 2 of my boosting project, but i could do it now since I'm gathering parts......... hmmmm. This may be more work than i anticipated, as always!

I am also not counting out a cam swap, but that still doesn't fix my compression issue.

This is the intake I am considering , along with the othe most common single plain.
http://www.promracing.com/parts-acce...-manifold.html

gbayfisher

I have been using some online compression formulas and it looks like I can drop my compression significantly by adding a thicker gasket, I mentioned it in my early posts.
I may reconsider using an even thicker one. I Can drop my comp down to 9.5 with .060 thickness hg, and down to 8.98 using the .090 gasket. That's putting me In a great spot to run 6-8lbs , and with the added cooling of the IC and meth inj, I will be ok. I think I will have to switch to a head stud setup now however.
Has anyone here run that thick a gasket on their boosted setups? I did some research and the majority of guys seem to have had good luck with the cometics in that thickness range. Any thoughts?

gbayfisher

Some of the goodies have arrived, and looking to piece together the last few.
So far, I have the head unit, pulleys, main bracket, braces, and mounting hardware, don't think anything missing for the super charging mounting, just supporting items now.
Still looking for a BOV, intercooler/piping , and possibly meth kit, and of course the head gasket swap.

Bullydawg

iTrader: (7)

D1SC? I would keep the intake and run it for a while! See how it does...

anesthes

iTrader: (12)

That much distance really concerns me. I usually run .039" gaskets with the piston no more than .005-.010" in the hole.

The other thing is, honestly, 6-8psi is almost not noticeable for power increase. I had a similar scenario on my C4 Vette a few years ago, I ran a powerdyne and it made around 8psi of boost and honestly it pulled just as hard without boost and full timing as it did with boost and reduced timing. On my other blown builds, 14-18psi, that's a total different story. Absolute animals.

If I were you I'd yank the the motor, stick the short block in something else, and build another motor (re-use those heads) for the blower.

-- Joe

gbayfisher

Yes, d1sc with 5 inch pulley, which should put me around 7psi.

As of right now I think I will keep the intake, and just concentrate on how I will control detonation, figure out the mounting, typical belt issues, and such, and then go from there. I have the season to ponder what to do next, perhaps an intake/cam/head swap for this winters project.

gbayfisher

Joe,

Is your concern the distance from the piston being.035 down the hole with a thick gasket , or the thickness of the gasket and possible blow outs? Just thinking out loud here. If the thick gaskets are an issue, who and why do some guys run them?

TBH, I was trying really hard to keep this engine in and not touch the short block, I had it in my mind that if it came to pulling this engine out, an LSX conversion was going in....... Damn.. Got me thinking twice.

Fyi, my build measurements are as follows:

-block height 9.003
-head gasket .039
-flat top piston down .035
-afr 195 heads with 75 cc chambers milled .030 (approx. 70 cc now)

Compression 10.17:1


Thanks

mark

no new tires

You'll have to go through me first.

gbayfisher

Things change fast in this sport. Friend of mine is pushing a callie 427 crank on me......but in the meantime, I still want to experiment with this build.

gbayfisher

through me 'first"

no new tires

I guess -

gbayfisher

Still not sure which way I am going here, but this is what I'm thinking.

I know increasing quench with a thick gasket isn't going to work as I had hoped, so I am left this.....
1. I can install the superhcarger as is and try to control detonation, which i know wont work very well.

2 I can change the small cam and go to single plane intake and spin it a little higher, which will help my timing issue and free up some ponies, run it like this for the summer.
The supercharger might work with this combo

3. Wait untill the driving season is over, and rebuild short block for boosting

Option 2 would be the most practical at this tme of the year since I dont want the car down for longer than a weekend or two.
I'm looking for an IC and meth kit if anyone knows of one for sale.

toronto formula

iTrader: (1)

Update....

gbayfisher

No updates regarding the SC, been so busy at work I don't have the time to even think about the car. Still trying to figure out what approach I want to take, buI will say it hurts looking at a beautiful d1sc just sitting there in a box.

I was dealing with a bad DFX clutch, now 1-2 synchro needs attention, so the t56 is coming back out yet again for a rebuild.

ZZ3Astro

Two thoughts on timing..


On my TPI build, I have found the engine to be very timing sensitive in the peak torque rpm range between 2700 and 3200 and then it tolerates a lot more beyond that.


Second thing is trust but verify the timing numbers you have in the tuning software - not just at idle but check with a digital timing gun at higher rpm to make sure the numbers still match.

gbayfisher

Good advice, and i will check that again to make sure the actual timing matches the software.

bk2life

any updates

gbayfisher

​​​​​​Yes!
Been very busy working on the car over the last couple of mths. I will fill in the details soon, but here is where it stands so far.
so far.

no new tires

Updates?

gbayfisher

Still chipping away on the project, might be able to fire it up this weekend for testing, will be updating soon.

toronto formula

iTrader: (1)

Mark any update???
interested to hear how it is going

gbayfisher

Hey,

All done, finally!

I pretty much just got it done this past weekend, it was a long , slow build due to the typical issues , and of course this thing called running a business..

Anyways, to summarize the build, her are some more details.

I did decide to switch out the FIRST intake. Yes I know the FIRST lovers are crying right now, especially considering this started off as a FIRST build and SC project, unfortunately, I had enough of the intake, and its tb, I just felt like it was time for a drastic change since I was tearing into the engine.

I ended up going with the Edelbrock set up. Here were my changes:
-Victor junior E
-3848 edelbrock elbow
-3869 edelbrock LS2 Throttle body
-224/230 114ls cam
-62lbs injectors
-compression drop to 9:1
-D1SC/ intercooler
-self rebuilt/upgrade t56....


I ended up going with a thicker head gasket that allowed me to drop my comp down to 9:1. Yes, i removed my quench zone completely, actually, i killed it, which seems to make a big difference in battling detonation issues and quench zones being borderline or just out of the optimal zone, by running a huge gap, it looks like i am safe .....so far. I did run the engine for 2-3 weeks naturally aspirated just to work out the bugs and get things in line before boosting, I went up to 34 degrees timing with zero knocks, and today for the first time ran 6-7 psi of boost with zero detonation, things seems to be going good , so far, so good! I ran into wideband issues, so stopped the tuning early today which sucked bad with cool, clean air........tomorrow.

Regarding the intake swap. The verdict is still out on the single plane over the FIRST. Like I said, running NA for the last couple weeks skews the results, but as it is right now, i do definitely miss the low and mid range pull of the FIRST, it was an absolute blast to drive on the streets, but the lack of rpm was starting to bore me .
Running the single plane with no comp isnt a fair trial, but as i added the boost into the engine today, i feel like this set up is really starting to work, nothing like the sound and feel of a screaming sbc under boost!

Onto the fitment issues. I ended up with a 1" spacer under the elbow to give me a spot to port some vacuum lines into , as well as to clear the fuel rail. This intake/elbow combo is definitely not Firebird/trans am friendly, I maxed out the under hood clearance, and i mean maxed out, to the point that i am considering a cowl style hood if i keep this combo around for long, I really want to turn the elbow around, but there is no way with the factory hood, idk what to do, will see after this season, might be time for a miniram......

I look forward to continuing to improve this combo, but i will admit it was a lot of work (as are most), but it is finally starting to come along nicely. My efforts were multiplied by tranny issues and clutch problems when i reinstalled my newly rebuilt by CENTERFORCE DFX, which has been a royal PITA since day one, after 3 "in and outs" im done with it and just reinstalled my df centerforce which has been flawless. I do have a Mcleod twin disk/ aluminum flywheel combo to drop in if i burn this clutch up this summer, if not, i will do it over the winter, i just want to drive the car for now.

Look forward to dialing this combo in, going to be fun!

My one issue coming up soon might be fuel delivery issues, i am only running the Walbro 255lph. I will have to wait and see how it goes while i dial it in some, i think im ok for 6-8 lbs, might be an issue for 10-12lbs.

Here is a pic of my tight engine bay.. Plumbing is still half fast, but i will clean it up as i go along , i want to weld most of it together once i know it works.

bk2life

interested in selling?

no new tires

Care to elaborate on that?

toronto formula

iTrader: (1)

Pictures and let me know if you are planning a sept visit to Cayuga

anesthes

iTrader: (12)

Long tube runners are tuned for a specific operating range. He needed a shorter runner to make power higher up.

-- Joe

Orr89RocZ

iTrader: (20)

IF boost was increasing with rpm then power would level off and hold the higher you rev it

anesthes

iTrader: (12)

I did this exact test 15 years ago. It's well documented in a thread called "Single plane manifold". One would assume the harmonic resonance only affects a naturally aspirated motor, but truth be told the exact same pulley combination on the blower made a lot more power, higher up on the RPM band on the shorter intake manifold. We're talking 10mph difference in the 1/4 which was roughly 11%. That's huge.



-- Joe

Orr89RocZ

iTrader: (20)

Thats true intake tuning effects all motors

But.....


A na tpi might be done by 4500 and require a 4600-4800 rpm shift.

Same motor with a linear boost with rpm supercharger will peak near same 4500 but power will NOT drop if boost increases. This manually extends the rpm range so you can now hold that power to say 5800-6000. Shift 6000-6200. Did this on a 383 tpi ds1c. This creates high average power

Sure a SP or other short runner will do more peak hp. But doesnt mean the motor cant rev out

anesthes

iTrader: (12)

Power might hold, but won't continue to increase. The shorter runner intake makes more power and at a higher RPM. If we're concerned about a drag car, or more importantly something like a boat (what I'm more into) you need the power to increase with RPM or you get bog. For land speed stuff I guess it doesn't matter.

What cam was in the 383 tpi d1sc and how much power did it make?

I have kind of a dillema with my 412 in my Formula, where the motor is too big for the cam so that's my RPM limiting factor, not the intake or heads. I don't want to go with a bigger cam because it will idle like an absolute turd. Should have stuck with smaller displacement SBC's.. Cam is 224/236. It stops making more power at 5500 and starts going backwards at 5800.

On a 355, a slightly smaller cam (224/230) pulled to 6200 no problem.

-- Joe

Orr89RocZ

iTrader: (20)

Cam was a 224/230 custom grind using comp xfi hyd roller lobes. Between xfi 268 and 280 shelf cams. Tpis big mouth system. Afr 195 i think.

Problem was throwing belts at like 5800. Limited boost cuz it was climbing with rpm and power was hanging on. It made 521 whp and 583 wtq on only 8 lbs. i would have to check the graph at the shop for exact rpms but i know it was like 8 psi by mid high 4000's rpm and made 12 at 6000. Then belt came off when letting off throttle. 5 spd car. The graph was flat from 4000 to 6000. Huge torque curve

gbayfisher

Just as anthesis mentioned, just the fact that the power band was done by 5k due to the longer runner design started to get a little boring, im starting to love the feel of hp . I would put money on my single plane low comp motor putting down more power and trap a few mile higher than my first with higher comp setup.
Adding boost to the First would have been a royal pain in the butt tuning wise, i feel this setup will be easier to tume, and far easier to drive.

Orr89RocZ

iTrader: (20)

How is tuning the first any different than the sp with boost? Efi is efi.

gbayfisher

Orr.

Didnt mean to say that it was different in theory, but in actual tuning, i did find getting the timing curve with the peaky power band of the First difficult ( for me at least) , but that could have been more of an issue with my intake/cam combo than anything else, something about it just wasnt right. So far with the time spent tuning this single plane combo, i find the linear power band a little more forgiving. Time will tell.
I really wish i had installed the supercharher with the First as acomparison because i tgink it woukd be one of the few boosted ones out there, but i know i would have had major issues with detonating, and i wasnt in the mood to fight that battle, combo was just wrong for boosting. Would have been fun, except there would have also been major traction issues, lol

NufNuffZ28

iTrader: (10)

On My Iroc power decreased slightly after 5500-6500 with increasing boost.


Don't have specifics off of my head. IIRC I shifted around 6300 at that point.