My 89 Camaro Project

[Schmieder]

Dave, I figured you did....own tuning. I found tuning pretty straight forward. It was the fine tuning where I could spend time over excel graphs, formulas, etc.

I come to like HPT but I REALLY would have fun w/ Megasquirt. Especially a 6x EGT system to keep a more precise AFR.

In about 2 weeks I'll have my 5speed swap done. 96 turbo GP goes 5-speed! with an EP LSD too. It was a big project so far.

[pocket-rocket]

If I do a turbo on my truck, like I would like to (John is egging me on as well), I've decided to go with an MS system. I would do a factory SVO Mustang or Turbo Coupe T-bird ECM, but I don't want to move backward on technology and use a dizzy when I've got two perfectly functioning coil packs already. That and I would like to more accurately be able to control spark timing as well. As good as the SVO and TC ECM was for it's application, I'm thinking the MS would be much better. I'm planning on upgrading things in stages. First stage is finish the small repair items I need to do to the truck (core support and a few others), upgrade the cooling and oiling system (cooling won't be hard with junkyards, oiling is mainly going to be an oil filter relocator with a larger filter, and possibly a cooler and gauge), stage 3 would be taking a factory underhood harness from a junkyard Ranger and connect the MS to it and swap it out one weekend and get a grasp on tuning with the MS, then part 4 would be rebuilding of a core engine, or just swap in a junkyard engine and rebuild the one in the truck (that's less than 3k miles from rolling 200k). Stage 5 would be breaking in of the rebuild, or swapping the original engine that has been rebuilt and break it in, then once it's broke in, stage 6 is boooooooooooooost! Since it's my daily, I can't have it down very long, hence the small and many stages, but if I'm able to get things rolling on the 92, I'll just drive that for a bit while the Ranger is down. In fact, I've been considering swapping to stock brakes on the front of the 92 since I have good 16's with decent tires just so I can drive it since the set of rims I want for the 92 are around $1,200...

Crap... Sorry for the slight thread jack, Dave.

[Superdave]

Lol...

If the FPR doesn't drop the pressure at idle there is a chance that you'll bottom out the idle VE tables, and you're right.. the injector pulsewidth does come into play there.

in $A1 you typically don't want to let the PW drop below .27ms but mine idles around 1.5Ms iirc so there is room to adjust there. However my idle VE table is extremely low already so if i can't iron it out i'll have to get into the ugly side of tuning.



i repaired my exhaust and gained another 2" or so of ground clearance, installed the trans cooler and fixed a ton of other stuff tonight. It should be back on the road for tuning very soon...

[2.8/3400 1985 Camaro]

I'm dying to see track times or dyno #s on your car....

[robertisaar]

there's another function of the FPR as well: correcting for pressure differential.

say you have 43.5PSI of fuel pressure and are shooting into atmospheric pressure(WOT), your injectors will flow what they're rated for(assuming they're rated at 43.5PSI).

now, let's say the FPR is disconnected(so we still have 43.5PSI behind the injector) and you're cruising at 55MPH at 15" of vacuum, since you are injecting INTO a vacuum, it will actually increase the amount of fuel that is drawn out of the injector due to there being a larger difference in pressure between the injecting and injected portions.

IIRC, most GM FPRs have around a 1:1 pressure rise/drop rate in relation to vacuum, so you should have nearly the same injector flowrate in all situations.

[pocket-rocket]

there's another function of the FPR as well: correcting for pressure differential.

say you have 43.5PSI of fuel pressure and are shooting into atmospheric pressure(WOT), your injectors will flow what they're rated for(assuming they're rated at 43.5PSI).

now, let's say the FPR is disconnected(so we still have 43.5PSI behind the injector) and you're cruising at 55MPH at 15" of vacuum, since you are injecting INTO a vacuum, it will actually increase the amount of fuel that is drawn out of the injector due to there being a larger difference in pressure between the injecting and injected portions.

IIRC, most GM FPRs have around a 1:1 pressure rise/drop rate in relation to vacuum, so you should have nearly the same injector flowrate in all situations.

See, now that makes much more sense along with the injector pulse.

[3400-95-Modified]

Its crazy you have a very similar balls to the wall agressive lopey idle like me, making the car sound like its got a SBC 350 in it, but then when you get on it, you get that smooth 3x00 even fire sound out the exhaust... LOL

Sounds great though and its cool to see your making good progress with it. Work looks very professional too, as it always does with your stuff.

Props!

[Superdave]

Thanks^


Finally got some time today to work on my trans cooler line situation... I yanked out the leaking stock lines and replaced them with all brand new -6 stainless braided line. I also re-routed them far away from the header so i shouldn't have any problems there.


Hopefully tomorrow i'll be able to get the VSS input to the ECM working and get it off the jack stands. With most of the annoyances fixed it should be pretty solid finally.

[Schmieder]

there's another function of the FPR as well: correcting for pressure differential.

say you have 43.5PSI of fuel pressure and are shooting into atmospheric pressure(WOT), your injectors will flow what they're rated for(assuming they're rated at 43.5PSI).

now, let's say the FPR is disconnected(so we still have 43.5PSI behind the injector) and you're cruising at 55MPH at 15" of vacuum, since you are injecting INTO a vacuum, it will actually increase the amount of fuel that is drawn out of the injector due to there being a larger difference in pressure between the injecting and injected portions.

IIRC, most GM FPRs have around a 1:1 pressure rise/drop rate in relation to vacuum, so you should have nearly the same injector flowrate in all situations.

I always figured it was to prevent the idle pulse width from becoming to short a fire time making accuracey an issue. Before the O2 can adjust, there will be excessive fuel (with out a FPR) so the IPW contracts and makes the IPW shorter and then less accurate.

But with the ability to tune the injectors at various vacuum/boost conditions (via MAP sensor) it would seem the FPR is pointless.

As i see it the FPR allows better idle/cruise conditions. Especially w/ larger injectors. Which ends up being an emissions issue as well.


Dave, stainless braided lines for ATF cooler, very nice. Some would call it over kill, I think it is building things they way it was meant to be built. Not like the modern crap that breaks when the warranty expires.

What kind of trans cooler are you using? B&M? I got a B&M that has a mechanical cool fluid bypass. Well, unless I can use it to cool down the turbo return oil it may be on sale soon.

How are you measuring IAT?



Robertisaar, you answered a question I was looking for a long time. 1/1 ratio FPR ( I could not find that answer until now)

[Superdave]

the stainless line was extra from replacing my main fuel line. I was able to do all 3 lines and have roughly 3" to spare with 20' of line. haha

Just a big Summit brand cooler in series with the stock one, If the trans starts getting too hot i'll upgrade to a big B&M but this should be fine.


IAT, measuring through datalogs.

[Schmieder]

IAT, was wondering since you have 6 intakes now, do you measure from just 1 intake and generally assume the other 5 are the same? Or have you found a way to average 6 IAT's together?

Or can you adjust each cylinder independantly via MS? Sorry for asking, I don't know the history of your ride.

Can't wait for the 1/4 mile run? I'de love to see/hear that beast run!!!

[Superdave]

After some trans problems i'm back on the road again.. lots of datalogging/tuning to do over the next few weeks.

I will say this.. the car is like DrJekyll/MrHyde when driving. Light throttle is all it takes to drive around and get up to around 45 MPH or so.. mid throttle and it gets loud, WOT is just hard to describe. I've driven 500+ HP big block cars that weren't this fun.

[Schmieder]

Glad to hear it is coming along. You definately have a unique ride.

How much HP are you estimating so far at WOT? I can only imagine what the intake sounds like at high throttle.

[2.8/3400 1985 Camaro]

Still dying to see a dyno or 1/4 mile vid on this car, lol. I reckon you're among my main competition in vying for fastest 60/6 fbody, along with pilsbry, other dave and maverick(if he goes boost can't recall if he is planning to boost or not), my goal is ultimately 10s and 400-600 hp.

I'll be starting automotive school soon as well, which means 3 things: 1: I'm getting loant money to bring the old beast back from the dead yet again, as I need a car for school 2: I'll have free access to some shiny tools including a dyno and lastly, the course I am taking has the students spend half of each semester on the job with a dealer, meaning I should also once starting that have money to start modding it again
At any rate, I envy your 'maro and can't wait to start comparing #s.

And oh hey, just noticed the guy who posted above me lives in pittsburgh too!

[Schmieder]

And oh hey, just noticed the guy who posted above me lives in pittsburgh too!

Yeah, for now. I'll probably be the only Pittsburgher w/ a 96 GP 5-Speed boosted.