...with disappointing results

Put down 242hp and 329ft-lbs-- SDPC rated the engine (their 350 TPI/Vortec crate) at 357hp and 417tq and the crank.

The first run the car was WAY lean... over 20:1, went way off the A/F graph at around 2500RPMs... it then settled down to 16:1 or so up to 5500. The consequent runs started out around 17.6:1 and evened out around 14.5:1 all the way to 5500RPMs... the pull started at about 2000RPMs from the looks of the graph.

I don't have a scanner, otherwise I'd run it through and post it. Where is all this power that I'm supposed to have with this motor?

I've got the stumbling idle problem until warm that somebody else posted a thread about, my mechanic is checking the CTS today, along with the O2 sensor-- he figured that maybe the sensor is on it's way out and that's what caused the car to lean out on the pull.

Where's that other 50hp I should have put down though?

 

How does it feel next to the 305?
How does the car idle with the hot cam? Is it relatively smooth?


What do you have done to the TPI unit? What injectors are you running? Any prom changes?

 

The car definitely pulls a hell of a lot better than my old 305 ever did even on the best of days.

It's running a custom burned PROM from Ed Wright at Fast Chips. The TPI unit is the stock plenum, SDPC Vortec base with SLP runners. I'm running Ford SVO 24# injectors, AFPR set @ 50psi.

The idle is relatively smooth after the car reaches operating temperature (before that it stumbles and runs slightly lean-- another thread on here recommended it was a bad CTS causing the problem).

Additionally, it was 99 degrees during the run. That wouldn't account for a loss of a presumed 50hp though. Especially when the 2002 SS after me put down 330hp and 320ft-lbs. on the first pull. Of course he was right at 13.0:1 right across the whole pull. And another 2001 SS put down 529 to the wheels with a slipping tranny and a 150 shot He had H/C done though-- and was running extremely rich.

 

Sounds a little weak. I would guess you should be around 280-300 at the wheels with your setup. Sounds like timing to me. What is the timing set at with the EST unhooked? Did you switch to a 350 knock sensor?
It is also possible the ECM is pulling timing due to detenation caused by your low RPM lean condition and it is not recovering fast enough to give you full timing where it should peak. You really need to get that fixed before you hurt the engine.

Charlie

 

What's your fuel pressure at on the peddle (dropping?)and can your pump supply the fuel that is required for your motor? Those A/F ratio's are ****, I'm surprised they even let you run your car on the dyno after the first run. You got to be around 12/13:1 to make good power, right now you run the risk of seriously hurting your engine. You might need to send that chip back for another burn.

 

We did install the 350 knock sensor. I was hoping for 280-300 at the wheels too

Very interesting... I thought of timing just now in the bathroom. I couldn't tell you what the timing is myself, as I don't have the knowledge or tools, but I'll pass this on to my mechanic.

What would advancing the base timing do? I know a little, not a lot, so I'm eager to learn.

 

It's got a brand new fuel pump in it (OEM replacement). The old fuel pump died and the car stranded me at soccer practice one night

 

Damn you should have put in a highflow one at that time, there really not much more money then the one you just put in.

 

I think I may have still had the 305 then. I can't remeber If that were the case, the 350 swap wasn't even on the map at that point.

 

This custom chip that you have now, is it programed for your current combo or your old 305 with the stock injectors?

 

It's programmed for my current combo with the SVO injectors. I sent the specs of the crate engine in to Fast Chips, and they sent me the new ECM.

 

If I where you I would get on the phone with Ed and get things straitened out before you start stepping on it anymore. Also how did the dyno guy hook up the WB to the car, was it after the cats?

 

After the cats, clamped to the exhaust.

If anybody should talk to Ed, it's my mechanic-- he's the one with the scan tool and the training

 

I can tell u were all the power is :-)

U said Ed Wright! Theres where all your power isnt!

Leant to do it yourself and see the amazing gains, u can do a better job than anyone else who is 1000 miles away ... Yes, I went thru this same thing when they said LT4hotcam. vortec heads? No problem , we've seen a lot of those with the same setup. BS flag to the nth here :-)

Mine ran the opposite, wayyyyyyyyyyy too rich although I am a SD application and u r MAF...

Either way they are far from correct

This isnt a flame either its just the truth, u want them to work with u , u send it back to them with a 3 day turnaround where u cant drive your car.. I went and ordered all my tuning stuff and never looked back

later
JEremy

 

Something is funny with that AFR. You put down near the TQ you were supposed to. 329/.8=411 TQ I'd think you'd put down more with non open exhaust.

There are also a few differences in your setup and thiers. They used Larger runners, bigger TB, 1.6 roller rockers, and open 1 7/8in Dyno headers. These will affect your HP. 300 hp at the wheels is 375 FWHP and even SDPC doesn't claim that high.

Check out this article from CHP. I'm gonna link the "power curves" page so if you want the main article you'll have to back up. It's the numbers from SDPC's engine test. It'll give you something to compare against.

http://www.chevyhiperformance.com/te...58/index4.html

Also, are after cat AFR readings valid?

Any change you can scan your Dyno sheet?

Keep us updated!

 

All of these TPI Vortec motors from Scoggin come with 1.6's...hence the 525/525 spec on the cam

 

Yeah...I just wasn't sure if he ordered the whole motor or built one up himself.

 

My engine has the larger throttle body they tested with (I ordered one since that's what they dynoed with-- I realize that my 305 headers are a restriction but I didn't think it would be a 50hp restriction, yes?). I thought the SLP runners were higher flow parts as well?

I ordered the complete crate.

 

You have all that air going into that motor now u need to get it out. You deff need a complete exhaust system with that motor. You spent all that money on it already mine as well get some headers. I have the Edelbrock TES on mine with the same combo but I built my motor I didn't oreder it from SDPC

 

I have SLP's 1 5/8" headers as well as their 3" full catback exhaust on the car already. There aren't enough pennies lying around for new headers at the moment.

 

"I realize that my 305 headers are a restriction but I didn't think it would be a 50hp restriction, yes?" Im confused then. Did you have the car dyno'd with the SLP headers on there. Those headers are fine with that motor even if they are the 1 5/8 ones

 

Yeah, those headers should be good enough. As suggested check your timing. Any change you could find someone with a scanner? You'd be able to see if there are any knocks. The SLP runners are high flow pieces, so that shouldn't be it. Are the HP and TQ curves smooth or are they jagged? Any drop offs or pits?

 

Yes, when the car was on the dyno the SLP exhaust and headers were installed. Headers and exhaust was the first thing I did to the car, three years ago, when it still had the 305 sitting in it. That's why the 305 headers are on the 350-- new headers for the 350 just weren't in the budget.

 

Yeah, my mechanic Jimmy has a scan tool. The car is down at the shop spending the night and another day or two while they install my Eibach Pro Kit, adjustable panhard rod, polyurethane bushing kit, Tockico five way adjusts and MOOG front end rebuild kit

The power curves for both the HP and TQ are smooth and unbroken. The torque curve is particularly flat looking, actually. Even on the first pull where the A/F went off the graph, there weren't any irregularities on the power curves... the power started to fall off around 5000RPMs, but I just attributed that to the airflow shortcomings of my unported plenum and base.

 

Hmm...I can't think of anything.... If it was jagged or had some dips I could have questioned some suff. Maybe some other folks will chime in. Good plugs, wires, strong spark?

 

Tell Ed Wright to make your wot a/f ratio 12.75 instead of his usual lean-*** a/f ratio. It's not safe. I don't know why he does that. My chipfrom him was 13.3 afr, and that's when I started burning my own.

Tell Ed to add some to the acceleration enrichment tables also, he never touched mine, and it had that same lean bog that you have.

You are probably losing 20 hp with the cat, and would pick up some with some longtubes in the midrange. Other than that, 242 at the wheels ain't bad. A club member put down 240 with a stock 92 gta with 170,000 miles on the motor, only changes were slp 1 3/4 headers and cat-back with a convertor and new tranny. He picked up 20 hp on the dyno by upping the fuel pressure 5-10 pounds.

 

you can't just say this A/F is going to be fine


this is the problem with tuning
you can't just use one solid A/F for all motors
cause each motor has different burn properties

if they all burned the fuel the same way we should have them set at 14.7 since that is stoich

but again different bore/stroke comboes
types of heads
exhuast
intake manifolds
cam timing and all that can make differences as far the a/f ratios goes


that is part of the reason I would never get a mail order chip
too many variables

it would be much much easier to just have somenoe enxt to you to tune it and get it up and working

 

In this case, what he got from Ed was too lean. Every motor is different, yes, but I'd rather be on the richer side than the leaner side, even if I'm giving up a little power.

Nothing wrong with the mail-order tune if you plan on leaving the car alone after you mod it and never mess with it again, but that never happens.

You need to record some data from a wot run either on a scanner or some data logging program and send it to Ed Wright, otherwise, your tune will always be off.

 

My mechanic has a scan tool and after further deliberation last night on his part, when I talked to him this morning he gave me the same response I got from you-- Ed probably burned the WOT AFR to stoich and there isn't **** we can do about it without ordering a new one (chip).

What about sending him the dyno graph that I have? That probably isn't going to get him the data you're thinking of though. Can the scan tool pull up the figures that Ed would need?

 

I doubt Ed put the WOT AFR tp 14.7...

You can run an AFPR and tweak your WOT AFR....but since you'd paid for the chip it should be fixed in there. Call Ed up and tell him what happened and see what he says.

 

I have a very similar setup you have except with 1.6:1 rockers and a stock TB. I had a custom chip done and it didn't run too great. I put a slightly modified stock chip in for now and it actually runs considerably better. I'm starting to do my own chips and think i'll get a bit more power out of it. Maybe there's someone local that can work with you and burn you a good chip?

 

You could always try your stock chip, it is richer than Ed's.

You have to record some data, or send Ed the dyno graph for him to know where to make changes.

 

i see you're in florida, here is a shop in florida that I bet could get your car going good.

http://www.vincihiperformance.com/

 

I talked to Fast Chip yesterday... as you guys said, they recommended that I fax them the dyno pull and let them burn me a new chip. Question is, if it's going to cost me any money because that is in short supply at the moment. They already had one crack at it and it didn't come out too well so hopefully they'll at least give me a discount

That said, they recommended I check for an ailing MAF and O2 as well. The MAF more than anything else... I'm about to head down to the garage and check up on the beast, I'll post updates later I suppose.

Has anybody had to have Fast Chip burn them another one? Do they discount it? And this is the daily driver that I can't really afford to give up-- they want me to pull the ECM and send it back to them. What are the chances you think I have of getting them to send me a new one and I send the old one back?

 

I see why some people think it is hard to learn to burn Their own chips and would buy a aftermarket chip, but as someone already mentioned they can't tune the chip properly for the car being that they aren't in it. Get a Cheap LapTop and a ALDL cable and Moates, or TunerPro Datalogging software and see what it is doing, Go to DIY PROM board and read and re read and Use the search button (it can pull up some cool and helpful posts) and learn to Burn you Own. With items out like AutoProm and PROMinator they have help simplify this task along with TunerPro Software. If ya want the best performance and to dial the car in the exactly with what it needs your gonna need to take some time, Dive in and research and post questions on the DIY Prom board.

For the Cost and Time it is gonna take FastChips to get the combonation Close you could buy the stuff and learn to do it your self and burn 10+ chips a day and datalog what each one is doing. And then when you do more Engine upgrades you don't have to go through the whole mail order thing agin just scan a drive and make adjustments accordingly.


If ya want it done right do it your self (just don't hesatate to ask for info,and recommendations.)

Just my .02

 

See if your stocker will work in the meantime. I sent my chip back to ed wright 5 times. You have to pay for shipping each time, but you only pay for the chip once, fine tuning is included.

The best way is to send him some scanner data.