Well, its official, I've got a turbo vette!

I'm running this on my spare engine. Stock Buick Roadmaster engine, iron head, 1.5 stamped rockers, 10:1 compression. The only thing done to it was a 58mm TB and a 230/236 +114 cam. I know this is far from ideal for a turbo setup, but its what I had in the motor. I'm running an Accel Gen 7 DFI with a dual sync for tuning. I'm running 5 psi for debugging the kit and I think I have a leaky headgasket.

So far everything is going pretty good. I've still got that perma-grin. This very very long project has finally seen some real world use and it feels GOOD!


Here is what I have for the turbo kit all engineered by me.

One SLP shorty header and one Buick roadmaster header
2.5" pipes merging into a 3" pipe
Turbonetics T-76 Ball Bearing turbo Q-trim with .96 a/r
Turbonetics Racegate
3.5" Down pipe
stock 2.75" split and through stock mufflers

2.5" intake piping through a 1000 cfm intercooler
All coating was done by Jet-Hot

It sounds great to hear it spool up and have the BOV go off. And the exhaust is much quieter than it was before.

here's some pics:

 

"...Got it gonin' like a turbo vette!" Sir Mix Alot

Nice!

 

wow congrats on the build! WE NEED A VID!!

 

The more pics the better! Plan on dynoing it?

 

I'm not really sure if I'm going to dyno it. I'll let the track times speak for itself. I was doing a 13.1 @ 109 mph before the turbo kit so if the spare engine holds together I'd like to see what the improvements are on 4-5 psi.

This winter, or when I blow up this engine, I'm going to drop in my fully forged 383 with a 9:1 compression, mildly ported heads(250cfm intake), cometics, and a better turbo cam(221/221 maybe). I should be able to run 10 psi on this motor and make some great power and torque with it.

I'm just counting the days down until I blow out my leaky head gasket on my current engine. This afternoon I watched my coolant temp start climbing after a hard 2nd gear blast. That was on the way back to work after lunch so I'll have to check it tonight. I'm hoping it will magically go away.

 

Looks good
Down get crazy on the boost with that stock short block. I like that 3.5" downpipe... I need to figue out how to get a larger one.

 

Don't give up on that cam just yet.

My cam is 224/236-114, which should be directionally worse than yours, yet I've run 143 mph in the quarter with a turbo in 90 deg weather and full street weight (3750+ lb) at ~19 psi boost.

A few people have made ridiculous power using dual pattern cams with more exhaust. I think it was Speed, Inc. that just made 990 rwhp through an auto on a turbo LS1 using a 236/242-112 cam.

Mike

 

Mike,

I was thinking of getting a cam that had a bit less overlap in it that the 8 degrees that I have now. It may end up hurting my top end power, but after all this is a daily driver. I would definately give up some top end if I can get some better tuneability and more midrange or spoolability. I wouldn't mind getting a larger exhaust by a few degrees to help vent the exhaust out the stock headers.

Luckily I was showing my car to someone and while it was idling they noticed that I was arcing one of my plugwires to the exhaust manifold. So today I pulled the down pipe and replaced the plug wire and gave it a fire-boot and all I have to say is WOW. All of my stumbling is now gone, the a/f ratios seem to be less out of wack, and that top end DANG! If I let out the clutch and hit the gas it breaks the tires loose at about 40mph when my measly 3.9 psi(dataloged) kicks in.

 

Actually, I think you have 5 degrees of overlap. Mine has 2, but I've seen turbo cars make alot of power with up to 15 deg.

 

Well, I turned up the boost from 4 to 6 psi. I'm not sure how much of a difference it makes, I think I'm getting a high rpm miss now. But anyways I think I'm going to start messing with the timing. Here's what I have so far, this is on all RPM cells in the timing table


psi_____Timing
-2____36
0_____34
4_____22
8_____17

That's a 2 degree/psi drop. I really don't want to blow up this engine. How much room do you guys think I have to move it up??

 

God damn, how much does it cost to have sex w/ that car?

 

I'll give you a good deal since the turbo will hack your equipment all to nothing

So nobody has any advice on the timing? Is it safe to go to 1.5 degree/psi or should I keep it safe where I'm at?

 

It really just all depends on the setup. I have always heard 2 psi for every 1 degree, and that works pretty good on my mustang. Keep in mind this is a factory turbo shortblock with low compression though(4 banger ford at that). My timing basically looks like this:

0 psi, 3000rpm-32 0 psi, 6000rpm-34
20psi, 3000rpm-16 20psi, 6000rpm-21

You will find that in the lower rpms you have to retard quite a bit of timing from the value that makes mbt torque. In the lower rpms, I would start out with 1:1. In the higher rpms, you can probably retard a bit less. Pulling 2 degrees for every 1 psi seems excessive to me. You are running a knock sensor right? Start out with 1 for 1, and watch your knock closely. I tune mine by ear, but it is much easier and cheaper for me to change a head gasket than it is for you. 1:1 starting with 34 total should be safe, especially at lower boost levels. Take what I say with several grains of salt, as my personal experience is based on factory turbo shortblocks. Mine feels like a total dog with less timing. It is pretty safe to just bump it up a degree at a time and pay attention. If you encouter knock (if by ear), take 2 degrees out at that point. Let of the nanosecond it rattles. If you haven't heard it yet, it sounds like rocks in a tin can.

 

The only thing I'm worried about is the fact that I'm running 10:1 compression, not the 8:1 that your stock ford has. The compression is one of the big things that determines how much timing you car get away with. I think its more of an apples to oranges thing.

I'd really like to hear from the guys that are running superchargers on stock engines.

 

As long as you have an efficient intercooler, you'll be fine running 6-8 psi even at 10:1. If you're really that worried, open up your combustion chambers or get some heads with bigger combustion chambers and lower your compression.

Also, you'd be amazed at the difference a simple muffler change would make.... right EngineerMike?

Mike