mn_vette

Well I finally got my turbo vette back up and running correctly. Yes Chris, you were right. My slip fit connection became unslip fitted and was leaking way more exhaust pressure than it was supose to.

But anyways, the temp was pretty cold low 40's and dropped into the 30's by the end of the night. I could easily see my breath when I left.

Here's my first run, data log says about 8psi

Reaction____0.3378
60ft________1.9792
330ft_______5.1473
1/8 ET______7.6731
1/8 MPH_____99.52
1000ft ET____9.811
1000ft MPH___115.16
1/4 ET______11.5893
1/4 MPH_____127.08

That tells me that my stroker motor took me down a second and up 10 mph from the 12.5 @117 that I had with my spare buick LT1.

I really couldn't keep traction when I would shift into second gear, half of the time the car started to go sideways. My computer ended up craping out on me too so I lost all my datalogging and tuning capabilities.

But in the end up turned up the boost. This last run was with about 12-14psi according to my not so trusty boost gauge. Notice anything weird?

Reaction_____0.113
60ft_________2.1108
330ft________5.465
1/8 ET_______7.9941
1/8 MPH______99.75
1000ft ET____10.1201
1000ft MPH___115.93
1/4 ET_______11.884
1/4 MPH_____128.19

I'm not sure why the mph didn't go up very much at all. I lost 0.3 from the launch and a little spin shifting into second, but the rest of the run was pretty close time wise. I tried a few different boost levels and it almost seemed to hurt the times and mph. I'd really like to take another look at my timing tables and what boost level that I'm acutally running right now but that darn laptop is now in need of a windows fix, go figure.

So according to the online calculators for mph and a weight of 3400# with me in it I'm above that 600chp mark that I was shooting for. And it's nice to know that I'm on the verge of breaking 100mph in the 1/8th. Well, there's your update.

qwiketz

you would definately think more than 1mph in the 2nd 1/8 with 4 psi more. What size turbo are you using?

neat

My turbo Buick did that same thing a few weeks ago. It ran the same times from 14 PSI all the way to about 20 PSI. Infact, it actually slowed down some with more boost. I don't know what caused it, but I haven't really dug into it much. Let us know if you figure it out!

86VX1

when you get the bugs out of the tune, 10's are in your near future.

major thumbs up man.

mn_vette

I'm running a Turbonetics T-76 ball bearing with a .96 a/r

I'm hoping to make it into the 10's and I really think that the tune is what is holding me up. I need to get borrow a new laptop from someone and see if I can get back to the track before it shuts down for the winter. It would also be nice if I could get some traction.

Hey Neat, What does your timing table look like at those boost levels? I'm thinking/hoping I've got mine retarded too much up top. Or I'm just maxing out my exhaust or something, but even then Boost in the engine should equate to more HP so I'm hoping its the timing, perhaps something to do with the IAT feedback and the higher boost levels.

neat

I don't know what the total timing is, but the stock Buick ECM doesn't use a MAP sensor so I don't know how it would retard timing based on boost since it doesn't have a way of knowing the boost level. It might pull timing based on RPM and a reading of more than 4.5V from the TPS sensor, but I doubt it. Even if the ECM were doing that, I should of still gone faster with more boost because the timing retard would of been the same for all boost levels.

Some of the Buick guys have suggested valve springs, and possibly a better exhaust. I am leaning toward tired valve springs, but that's probably not your problem considering you have a new engine.

Sorry I'm not more help. Good luck man!

TONYDEE64

You will absolutely be solidly in the 10's with a good tune...

AKS Racing

10s should be in your future.

qwiketz

if not faster with a 76 on a stroker.

lcvette

awesome man! I am very glad that you found the leak, I was hoping thats what it was and not something more severe! don't care about being right..much..lol

I hate to say this my friend but I am willing to put some money on it that even though you are cranking up the boost.. she is peaking and then petering out up top because you are beyond the flow of that Q-trim turbine wheel. I am seeing alot of that over on ls1tech with the qtrim wheel.. it is really maxxed on a mild 350 and you cammed and heads 383 is just corked on the hot side.. I bet your preturbo backpressure reading is more then 3:1 intake pressure. the reason you are seeing minimum gains with more boost is because the gate is staying shut and you pushed yourself out of the efficiency range and flow capacity of the small q. you may want to investigate upgrading to the new turbonetic MPS wheel which is lighter then the qtrim so spool won't be effected and it is larger, very close to a GTS wheel which can outflow the base Q-trim wheel by a ton! the GTQ wheel from precision which is similar in size to the base Q-trim from tnetics outflows it by a good margin and even those are showing signs of elevated backpressure on more then 355ci motors. give jose from www.forcedinductions.com a ring, he can swap your little wheel out for the bigger MPS wheel and I think you'll see a nice jump in power as long as your dp and exhaust isn't too small still.

also, can you run an open downpipe easy? if so try running an open downpipe, that will reduce some of the backpressure on the turbine wheel and if it is the cause as I suspect you just see a nice little jump in top end power. if this is the case definately get the bigger wheel.

ps.. My Turbonetic T76MPS unit is on the way... hope to have my car running soon again.. this cold weather is screaming for some boost at the track!

great times for that 8 psi setting.. I know you have got to be stoked!!

Chris

SloRvette

My 1000 hp Buick picked up ~ 31 mph in the 2nd eighth. The second eighth will stay pretty similar for a given turbo. When you pick up power you'll see it in the 1st eighth times.

I still would have expected to have seen the 1st half numbers pick up with the added boost. Looks real similar to what you were seeing on the dyno previously.

mn_vette

Hey guys,

I got my laptop up and running and checked the timing, at 8psi I was running 24* and with 12psi I was running 19*. I'm pretty sure that there's some room to up the timing. I think I should be able to turn it up to about 24 at 12psi. That's a 1*/psi drop. What do you guys think? Am I playing with fire by doing this??

Baldturbofreak

Just for future reference, if you find that the tune is right but it still picks up no more HP with more PSI - head right to the valvespring. I just had one hell of a battle with a LS-1 and a big honkin turbo, ask poor Chris about all my whining.
In the end it was valvesprings that were significantly lighter than what they were "supposed" to be. Installed height they were 88lbs-102 lbs. Add 10 psi to a 2" valve and it just took 31.4lbs of seat pressure away. In additon the severe duty valves were heaver than stock. In the end I ended up setting a new set of manley dual coils to 165lbs on the seat and 380 over the nose. A touch noisier at idle but when you get on her- all I can hear is creaks and groans from the torque beam.

Mo_Bandy

I have had the same problem with utotap... it logs great until you REALLY need it... ~RANT~

I had been chasing that gremiln for some time now and Autotap denies that it exists... Everytime I go into WOT logging it GRACIUOSLY skips the whole stinking RUN.... until I let off the throttle

I gave up and I'm runnning a PLX r-500 that will log up to 4 analog inputs without going through the ECM. AND at 10 logs per second!

Congratulations on getting it around... I agree there should be no reason not to see 10's

Go get'em

Mo

LD85

@ how much does a Turbo setup cost?

Less than a SC setup?

mn_vette

LOL, if you have to ask you can't afford it.

It probably cost me about the same as a supercharger setup, but this is a real supercharger set up. Not the out of the box kits that Vortech and ATI sell. Oh, and by the way that doesn't count the endless hours of custom work that had to be done. This is not a kit, its a one off custom job. Total cost, I'm not sure.


Well guys? Do you think its safe to bump the timing up to about 24*???? Of course I'll be doing this in one or two degree incraments. The very last test and tune of the season is this Wednesday and I'm going to try and be there. I hope the weather holds.

lcvette

DUDE!!!!! go get some race gas and be done with it!!!!!!! lol

I cannot tell you how much difference it makes.. I slap the 110 in it an I was able to add lot o boost no problemo. maybe you can see if there is a citgo nearby you that sells the 110 leaded .. its only like 4.39/gal put some in and get your glory run! by the way I was able to squeeze 23* total timing after torque peak on 21psi boost.. advance at torque peak was 19* and I ramped it up quickly from there.

on a side note... for the 250 bucks I spent on my knock module for the DFI it has been invaluable... it records my knock retard which was what helpd me write my timing graph until there was none whatsoever.. whether you run the race gas or not it may help keep your motor alive while tuning.. especially when pushing the envelope on timing advance!

good luck man.. and like I said.. keep your torque peak timing low and then ramp it up after that.. it will help in the higher revs and keep you safe at the highest cylinder pressure point!

Chris

LD85

So it cost @ $10k when complete, about what my engine cost.

lcvette

no way it was only 10k... he has more then that in just the motor, heads, and engine management and wiring harness... then the turbos stuff probably set him back a good bit. realistically with eveyrthing from fuel to engine management and the rest of what is required to complete a full on setup including the little nick nacks everyone forgets to account for.. look more in the 15-20k range!

Chris

Bowtie8

Brian

I had an opportunity to watch your car go down the track last Wednesday, And first off, you need to put some ET Streets on the back. You are launching very soft due to low exhaust flow and the turbo not spooled, this will save your DANA 44 and will also allow you to shift and hold 2nd gear without pedaling it. Thats what I heard when you hit second, I heard you lift.

In addition I have tuned a friends LS 427 TT 67mm and because of combustion chamber difference your LT1 will tolerate more Timing than I put into the LS motor.

What we found was set the VE and fuel up to 11.5:1 at WOT. I know its fat, but nice and safe and with the heat the extra fuel will help keep the motor from pinging. In addition once the fuel is fixed in your F.A.S.T. run the timing up 2 degrees at a time. I know for fact that at 14psi it will handle more than 19 degrees of timing. I remember you said it was an 8.5:1 motor correct.

After you get the timing where you want it, increase the boost by 4psi, buy a 1/2 tank of 116 from Milan and put the ET Streets on the back. It was a pleasure meeting you

Best
John