my turbocharged 3.1 V6/5-speed Cutlass Supreme sedan

[malibuolds]

Quote:

Originally Posted by ThreeTurbos thats pretty cool what u have done with that car, props where due. they are due here. nice job.

hey thanks man even though the "turbo kit" already existed thanks to Pontiac & ASC/McLaren, it was still quite alot of work! it's a bit different too...no one will expect this dark blue '91 Oldsmobile Cutlass Supreme sedan to be anywhere near as quick as it is. i would only expect mid/high 14s from this car at a track, but that is a whole lot better than the 17s it would have run before.
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Joshua Mitchell
'89 Lebaron GTS - T2/A555
'91 Cutlass Supreme sedan - 3.1 Intercooled Turbo/Getrag 282 5-speed
'94 Bonneville SSE - 3800 SI/HM-4T60E

[Ondonti]

a holset would probably work a lot better then the huge T4 im using.

[xtrempickup]

well, i guess you live and learn, damn interference motors, i better that doing all that work sucked. But probably will never do the timing chain agian

[GForced]

very cool, motor looks like it should have been there from the factory, instead of the grand prix, has better looks too IMHO, adds to the sleeper effect

[malibuolds]

this car has been freakin me out since i've finished it.

first it was breaking the timing chain....got through that just fine albeit after a ton of work....

then the first day i have it running again the turbo is smoking like CRAZY! lots of smoke, and oil was seeping from between the downpipe and turbine, as well as leaking down out the open downpipe. not only that, but i was running the engine without an air filter (just checking things over) and i noticed the compressor wheel was barely even spinning! i was convinced the turbo was shot even though it had ZERO shaft play. then a friend came over the next day and i was going to show him the problem....well the problem just went away! no more smoking at all, no more oil leaking from the turbo anymore...very strange....

then it was running like absolute crap...after checking lots of things i finally find a spark plug with a hairline crack in the porcelain. replaced that, car runs like a champ!

then a few days ago the oil pressure gauge was reading almost no pressure at all. at that point i was ready to give up and just part the car out. a few days later i start the car up and oil pressure is great. drive around for awhile and oil pressure is still just fine. then i noticed the gauge started freaking out bouncing all over the place. then it went back to reading low oil pressure. sooooo...it's the sending unit THANK GOD. jeez even driving the car today the oil pressure gauge was sitting at zero. engine runs great, sounds great, good power, oil looks perfect and is full.

this car sure likes to freak me out. anyways...everything is great, i just need to install my boost and A/F gauges before i put the grainger valve in and up the boost to 10psi. you can be SURE i'll be posting vids of that i'm really looking forward to getting a vid of my T2 Lebaron GTS against my Turbo Cutlass.
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Joshua Mitchell
'89 Lebaron GTS - T2/A555
'91 Cutlass Supreme sedan - 3.1 Intercooled Turbo/Getrag 282 5-speed
'94 Bonneville SSE - 3800 SI/HM-4T60E

[Ondonti]

You think the oil just burned wherever the leak was and plugged it up?????

I will start installing around the 15th of August. Im very excited.

[Heavytank2]

Quote:

Originally Posted by malibuolds i should admit that this was a VERY low budget turbo project. like i said in my first post, i turbocharged a previously naturally aspirated 3.1 MPFI engine. i did not mention however, that said engine has 227,000 miles the shortblock received a new Melling HV oil pump and that was it (besides cleaning the holy heck out of EVERYTHING). the engine ran great when it was NA, and it was fairly clean inside despite the high mileage. it got a new timing chain set only after the first chain broke. i did use TGP heads, which were hot tanked and bead blasted, very slightly resurfaced, new expansion plugs, 3-angle valve job and new valve seals.

Another thing we have in common, my GP had 201,000 miles when I SOLD it for $800. Neighbors of the person who bought it says she got the trans fixed and loves it.

Talk about a freakin' workhorse... the early GPs with the 3100 were great cars. If I had the money to fix it I'd still be driving it now.

[Ondonti]

my 3.0 turbo just started for the first time.

[malibuolds]

Quote:

Originally Posted by Ondonti my 3.0 turbo just started for the first time.

cool got any vids?

i'm still working out a bunch of little issues with mine. i really need to get a PC (i'm a Mac user), Pocket Programmer, and GMPCM software so i can tweak the EEPROM. i already have a Mastach ALDL cable and i can't wait to finally see what's really going on.
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Joshua Mitchell
'89 Lebaron GTS - T2/A555
'91 Cutlass Supreme sedan - 3.1 Intercooled Turbo/Getrag 282 5-speed
'94 Bonneville SSE - 3800 SI/HM-4T60E

[Ondonti]

Well I need a laptop so I can datalog.

I wont have any vids till I get back to Utah. My friend would gladly do that for me.

replaced my plugs and the car runs/drives great now. Amazingly fast. I thought 14.8@92 was fast n/a. Now 2nd gear feels more powerful then 1st gear did before.

[PentastarTurbo]

very nice ride, total sleeper! I cant help but think 3.0 with those exhaust manafolds... I saw a 3.1 turbo intercooled.. cant remember what it was in and for some reason im thinkin a cavilier vert a little while back? mite be wrong.. it was an automatic.. I remember seeing the intercooler and sayin.. Thats pretty close to the T2's

good work.. looks like it came that way.

[malibuolds]

well i'm slowly getting the bugs worked out. i found a nice sized hole and several cracks in my EGR pipe, and the O2 sensor seems to be dead. i should be replacing the EGR pipe this week and i am converting to a 3-wire GM O2.

iTurbo was nice enough to buy me an M&M Racing grainger valve MBC and holy crap! this car REALLY picked up! previously all i had was a straight vacuum line running from the fitting on the compressor inlet and the wastegate can. at first i just blew through the g-valve until i couldn't blow through it anymore and installed it. that helped a little. a few days later (after checking plugs several times) i tightened it up one full turn. wow! that REALLY helped! i'm assuming it's around 7-8psi right now and i am convinced it will now beat my GTS. unlike my GTS, this car has almost zero lag....mash the gas and it goes! i haven't run them together yet but it would be real close even though the GTS is at 13-14psi right now. unfortunately, i think 10psi is as high as i dare go with this little Garrett T25 before it starts pushing super heated air.

i cannot wait to start datalogging! as soon as i get a cheap laptop off ebay i can start; i will probably use Datamaster TTS. i'm also going to be buying the hardware to start EEPROM programming soon, all i need is a Willem EPROM programmer and a few EEPROMs and i can start and GMPCM software (thank god for GMPCM.com community...probably what D-cal is to TD tuners). my MemCal still has the 27C256 EPROM in it, and i need to swap it out for an 29C356 EEPROM so i don't have to buy a UV eraser. i also need to get either a ZIF socket installed in the MemCal or get a Moates G1 adapter.

anyways, i'm hoping to hit the strip at least once before the season ends. i really think i can get a good 60ft since i find this car so much easier to launch than my TD. with 10psi i would really like to see a 14.7 ET but i don't know if that will be achieved at my altitude (4900ft). i will definately be taking the car to the dyno at PFI in Ft.Collins this fall sometime. my goal is 220whp & around 250wtq after some tuning. i know it doesn't sound like much, but the engine is rather bottle necked with this T25 at the moment. too bad i can't afford a Garrett GT2871 or a T3/T04E 50 trim and a new crossover pipe. i really don't want much lag with whatever turbo i eventually upgrade to.

anyways, enough rambling. race vids between this car and my T2 GTS coming soon i will also be racing my friend's 2000 Grand Prix GTP with a few mods as well.
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Joshua Mitchell
'89 Lebaron GTS - T2/A555
'91 Cutlass Supreme sedan - 3.1 Intercooled Turbo/Getrag 282 5-speed
'94 Bonneville SSE - 3800 SI/HM-4T60E

[Ondonti]

Im getting away with a full t4 turbo. 240whp on 5 psi.

But I blew my headgasket because I exceeded the fuelpumps capacity.
Dont do stupid stuff like me and turn up the boost a little when you are already on the edge.

Now I have the sucky job of doing 2 headgaskets. I also have some exhaust leaks to fix.

Good luck. I think the v6 thing is very fun. Take a motor that is already torquey, and give it some killer top end. You soooooo need a bigger turbo.

[malibuolds]

yeah my car already has a TGP fuel pump, it's the same part # as the '90 Corvette L98 fuel pump. not a Walbro 255, but good enough for now.

yes this T25 is ridiculous it is fun in that it has no noticeable lag, but it is soooo short lived. up past 60mph it doesn't pull very hard at all. 1st gear is a tire screamer, 2nd is FUN!!! 3rd is alright, but 4th and ecspecially 5th is just blah. for a T25 it is rather big; .80 A/R compressor and .68 A/R turbine....but what the hell was ASC/McLaren thinking when they chose a T25?? ugh. definately need a bigger turbo. i could probably aproach mid 13s with a better turbo.

the next bottle neck is the upper and lower intake manifolds. the runners are extremely long and narrow. good for low end torque but not horsepower. i could step up to 3100/3400 stuff, but that would have to include everything from the heads on up, and then there is the problem of the rear exhaust manifold having a dump i would need to somehow block off (or extensively modify the TGP exhaust manifolds), along with a custom turbo crossover pipe i would need to have fabbed up. i don't even want to think that far ahead.
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Joshua Mitchell
'89 Lebaron GTS - T2/A555
'91 Cutlass Supreme sedan - 3.1 Intercooled Turbo/Getrag 282 5-speed
'94 Bonneville SSE - 3800 SI/HM-4T60E

[Ondonti]

The T4 turbo does have lag lol.

No boost below 3000 rpm's..........but top end is insane in any gear. Wait, until I run 8 psi and max out the fuel pump.

The big turbo seems to handle a LOT more HP/psi then your t25. Im looking at around 18hp/psi. Course Ive got the supporting mods to help that. Wish I wasnt so greedy that I blew the headgaskets.

If you go full 3" exhaust/dp and big turbo, big intercooler, Im sure you will be just fine. I dont think the long runners are going to hurt you that much unless you are looking for extreme power and poor drivability.