New Acquisition: dohc turbo

Shaun41178(2) · Post by **Shaun41178(2)** » Tue Jun 03, 2008 12:18 pm

^ you joking?

FIEROAJ · Post by **FIEROAJ** » Tue Jun 03, 2008 2:09 pm

Shaun41178(2) wrote:^ you joking?

Well no, V8Archie's V8s perform so well (especially the carbureted ones) that I just didn't think this V6 was up to the task. Also lets face it Shaun, you are not as good of a mechanic as V8Archie. Look at his LT1s!

:la:

Shaun41178(2) · Post by **Shaun41178(2)** » Sat Jun 07, 2008 6:50 pm

how long does it take for loctite to dry? its the red 262. There is nothing on the label letting me know.

Shaun41178(2) · Post by **Shaun41178(2)** » Sun Jun 08, 2008 12:35 am

found it

Fixture- 5 min.
Full Strength- 24 hrs.

Seals against leakage and corrosion; unaffected by liquid fuels, lubricants and most chemicals. Temp. range: -65Âº to 300ÂºF

lucky · Post by **lucky** » Sun Jun 08, 2008 12:55 am

Shaun41178(2) wrote:Who was talking about using red threadlocker on fuel lines? Did I read that on here before?

I have a npt threaded fuel fitting thats leaking. Didn't someone say you could use red threadlocker 262 or whatever number it is on threaded fuel fittings to keep them from leaking?

Or was it a different product?

Red's supposed to be permanent. Dunno why you'd use that on a fuel line. IIRC green has highest chemical resistance, but is hard to find at most stores. I'd go with blue on a fuel line if you can't find green.

befarrer · Post by **befarrer** » Mon Jun 09, 2008 2:18 am

Green is a sleeve retainer. More perminant than red.

The Dark Side of Will · Mon Jun 09, 2008 9:20 am

Green = Maximum Strength Retaining Compound

It is NOT threadlocker.

Shaun41178(2) · Post by **Shaun41178(2)** » Wed Jun 11, 2008 7:25 pm

threadlocker held/holding for now. Fuel leak is fixed, oil leak is fixed, time to start tuning.

Either the gauge is wrong or the car is stupid rich. Like sub 10:1 at idle and the whole time at WOT.

Plus the tach isn't reading correctly. It hits 6200 rpm when the car is probably in the upper 4's somewhere, and it won't go any higher. It pegs out at 6200 rpm. Ideas on a fix for that since the signal is coming from the coil packs I am guessing?

Factory dohc injectors are 22 lbs correct? I am tempted to put the stock chip and injectors in to see how it runs on the factory map.

Aaron · Post by **Aaron** » Wed Jun 11, 2008 10:53 pm

Shaun41178(2) wrote: Either the gauge is wrong or the car is stupid rich. Like sub 10:1 at idle and the whole time at WOT.

Plus the tach isn't reading correctly. It hits 6200 rpm when the car is probably in the upper 4's somewhere, and it won't go any higher. It pegs out at 6200 rpm. Ideas on a fix for that since the signal is coming from the coil packs I am guessing?

Factory dohc injectors are 22 lbs correct? I am tempted to put the stock chip and injectors in to see how it runs on the factory map.

If it is below 10:1, it won't rev up, or spool the turbo. As soon as it starts to build boost, the car will stumble out and won't rev any higher. Also, obviously stupid rich at idle. I doubt that the gauge is off, but check it on your 2.8. Remember the car is on a 3.1 code, so none of the numbers are going to be remotely close to a 3.4. Needs to be tuned across the board I'd say.

The tach signal comes from the coil packs, and runs directly to C3 on the C500. I see no reason for that be off.

They are like 23 or 24, depends on the years. Anywhere between 22-24. I would give the stock base map a try, just don't try to make boost with it.

Everyone talks all this shit about how my piggyback is half ass and all that, but the reason I did it is so that I don't have the issues you do. I'm running a far more modified engine, that should have much more tuning issues, yet it runs perfect until it gets on boost, but that is easily adjusted and fixed. I'd suggest you go to a stock ECU/chip with a piggyback. Use the piggyback I've got, and I can give you a tune that will make it run near perfect too (The baseline I got from Tim's turbo 3.4).

Shaun41178(2) · Post by **Shaun41178(2)** » Wed Jun 11, 2008 11:57 pm

I am running a 7727 ecm so its factory gm stuff. Its jus the tune is way off of it with the chip thats in it, or some sensors are not correct. I haven't checked the map yet to verify its a 2 bar, so maybe one problem is there.

I have no problems with a piggyback. I run one on my pushrod setup.My chip in the pushrod car was close and I was able to tweak it with the piggyback. the dohc setup is off really bad so that needs to be addressed first before I go further with piggybakcs or other such things.

Also it builds boost, about 2 lbs or so and thats it.

you know the color wire off the coils that feeds the tach?

Aaron · Post by **Aaron** » Thu Jun 12, 2008 12:08 am

Shaun41178(2) wrote:I am running a 7727 ecm so its factory gm stuff. Its jus the tune is way off of it with the chip thats in it, or some sensors are not correct. I haven't checked the map yet to verify its a 2 bar, so maybe one problem is there.

I have no problems with a piggyback. I run one on my pushrod setup.My chip in the pushrod car was close and I was able to tweak it with the piggyback. the dohc setup is off really bad so that needs to be addressed first before I go further with piggybakcs or other such things.

Also it builds boost, about 2 lbs or so and thats it.

you know the color wire off the coils that feeds the tach?

There is obviously a problem with the chip. The MAP probably is a 2 bar, I doubt Kohburn would forget that aspect.

Ok, that was just an easy stab at most everyone else here. The DOHC setup is off, because you are on a 3.1 ECU/chip. You'll need a full tune by someone very familiar with GM OBDI, either a local shop, or a tuner far away (Ryan).

Any stumbling when it builds boost? When mine was 10:1, it would stumble hard as soon as boost came on, and wouldn't build any.

The wire is white.

Kohburn · Post by **Kohburn** » Thu Jun 12, 2008 8:30 am

i think i may have another tach incase that one is bad shaun.

has a chip from darth that wouldn't start - no real fault of his since i wasn't able to give him much to work from. I burned the code from a guy on 60*v6 who was running the same computer on his 3.4 dohc... it was a start.

if i hadn't sold it I was going to rewire it to a stock ecm with a greddy e-manage piggyback while upgrading the turbo and injectors.

Kohburn · Post by **Kohburn** » Thu Jun 12, 2008 8:31 am

oh yeah - the guage is driven off the wide band - but the computer is driven off the narrowband sensor.

Aaron · Post by **Aaron** » Thu Jun 12, 2008 10:35 am

Kohburn wrote: if i hadn't sold it I was going to rewire it to a stock ecm with a greddy e-manage piggyback while upgrading the turbo and injectors.

If I was Shaun, I would do this tomorrow. It will be far cheaper than paying someone to build a complete tune for his car, and that's what it needs. Shaun, if you are interested in using a Split Second FTC1, I have Tim's maps here. Basically, you'd need to rewire the ECU plugs for a 3.4 DOHC ECU, which will, no doubt, be a royal pain in the ass.

But, then you can run a stock chip, and the car will run perfect off boost, so it gives you a great starting point. Now Tim, the guy I have the maps from, spent weeks tuning his turbo Monte Carlo, and it ran flawlessly. Made 325whp at 10psi, through a long 2.5" exhaust and a slushbox 4T60e. He also used the FTC1 to tune the ECU for the 42.5# injectors, whereas I used the stock chip. So you can hook up the stock ECU, hook up the piggyback using Tim's map, and I bet your car would run nearly perfect, even on boost, even with the large injectors.

As for the gauges, that is how it should be.

Billybo455 · Post by **Billybo455** » Mon Jun 16, 2008 12:33 am

need some stock l67 injectors?

Shaun41178(2) · Post by **Shaun41178(2)** » Mon Jun 16, 2008 6:19 pm

stock l67 injectors are whats in it now. Thanks though.

I might rewire it, I might not. I have a lot of engine bay cleaning up to do, and familiarizing myself more with the engine bay and wiring before I go tearing stuff apart.

I found the 3.1 al heads ported flow about the same as the dohc heads stock. So other then the timing maps and fuel maps, the flow should be about the same for airflow if calculating for a worked over 3.1

I need to get Ryan some real data is what I need to do. Be it aldl scandata or something. Maybe finding some cheap 22 lb injectors and going on a road trip to indiana would be the best bet. its long down the road, I dont' plan on having this thing running tip top in a few days. Its going to take months the amount I work on it. It took me about 3-4 months to get my pushrod setup dialed in the way I wanted it. Runs good though so I am in no hurry for the new setup.

AkursedX · Post by **AkursedX** » Mon Jun 16, 2008 6:33 pm

Shaun41178(2) wrote:stock l67 injectors are whats in it now. Thanks though.

I might rewire it, I might not. I have a lot of engine bay cleaning up to do, and familiarizing myself more with the engine bay and wiring before I go tearing stuff apart.

I found the 3.1 al heads ported flow about the same as the dohc heads stock. So other then the timing maps and fuel maps, the flow should be about the same for airflow if calculating for a worked over 3.1

I need to get Ryan some real data is what I need to do. Be it aldl scandata or something. Maybe finding some cheap 22 lb injectors and going on a road trip to indiana would be the best bet. its long down the road, I dont' plan on having this thing running tip top in a few days. Its going to take months the amount I work on it. It took me about 3-4 months to get my pushrod setup dialed in the way I wanted it. Runs good though so I am in no hurry for the new setup.

You should coordin ate something with Ryan at the 25th. You guys could use my garage if you need to do any work.

Aaron · Post by **Aaron** » Tue Jun 17, 2008 2:32 am

Shaun41178(2) wrote: I found the 3.1 al heads ported flow about the same as the dohc heads stock. So other then the timing maps and fuel maps, the flow should be about the same for airflow if calculating for a worked over 3.1

You found the wrong data then. I don't think there is a person in existence who can get any 3.1 head to even close of what the DOHC does stock. Not even a ported 3500 head beat my stock numbers.

Series8217 · Post by **Series8217** » Tue Jun 17, 2008 2:38 am

Yeah uh the 3.1 is not going to flow nearly the same. Heads suck compared to the DOHC (even when ported) and displacement is lower.

Shaun41178(2) · Post by **Shaun41178(2)** » Tue Jun 17, 2008 12:36 pm

I think my 3.1 heads flowed around 238 cfm around .500 lift at 28 inches. I have seen dohc heads flow a peak of around 262 and that was a lift well beyond what the stock cams go. Stock cam lift is around .370.

Measure the flow of a dohc head at .370 and my ported 3.1 at .500 and they will be close to flow.