Grsmonkey's Turbo build (updated 10/10/09)

[Shadow]

Actually, it's ...... N...evermind.

[Scottinva]

Actually your wrong once again. http://en.wikipedia.org/wiki/Jury_rig

Also my monster e28 runs 15.5 in the quarter. See here, no coffee cans.

[Brad D.]

Let's quit shittin' in Mike's thread.

[turbodan]

Actually your wrong once again. http://en.wikipedia.org/wiki/Jury_rig

Also my monster e28 runs 15.5 in the quarter. See here, no coffee cans.

When you're trapping 112, let me know.

[Scottinva]

Send some money my way, i'll make this shit happen.

[turbodan]

[M. Holtmeier]

I guess I need some better video...

The rev limiter works! I'm not much of a 5 speed person yet, all them dang pedals to deal with. I also found that my AE is still not right, so the video wasn't just for showing off. The BOV is just a bosch bypass valve, I was hoping to keep it as quiet as possible, so I an open blow off is not happening.

What really gets me guys is that when I look at turbo ignition maps the timing at 1 bar is either exactly like mine or only a couple degrees higher/lower. I don't how many people are running 9:1 b35 motors at 15psi and a stock cam, but I thought I'd be able to squeeze more timing out of my low comp. (7.7:1) hybrid. I'm thinking it's cam time.

[George]

Post up your VE and Spark maps.

[wkohler]

I was/am impressed, so .

[M. Holtmeier]

I could probably work on both maps a little more. I'm curious to try some race gas and see how much power I can extract from timing alone.

[turbodan]

I could probably work on both maps a little more. I'm curious to try some race gas and see how much power I can extract from timing alone.

This map seems inconsistent. You seem to pull a lot of timing out between 100 and 130 kpa. If 33 degrees is good at 100 kpa, 28 should be good at 130. You should be able to dial in a little more across the map at 150 kpa too. It shouldn't be sensitive to detonation until you're in the 160-180 range and up. The bins around 180-200 above 4000 rpm could use some work as well. If you can use 16-17 at 200 kpa, you should be able to run a few degrees more than that at 180. You should never have flat spots in your table, nor should you have sudden, steep drop offs.

If you're not up against detonation with your current tune at your current boost level dont expect to make any more power with race gas. Its all about minimum best timing. If you're already there on pump gas you've got nothing to gain from running more expensive fuel.

[Nebraska_e28]

Somethings missing here.... You didn't post the best video of the bunch!

[M. Holtmeier]

Somethings missing here.... You didn't post the best video of the bunch!

Ohhh Kay...


Me: [opens hood]"What's on fire?"
LJ: "Hmm, I think it's your brakes!"
Me: "Yeah, they never get used."

[M. Holtmeier]

Dan, thanks for having a look at the maps. To be honest, I haven't even thought of the bins directly above 100kpa since I dyno'd at 10psi. The dyno op had me pull a bunch of timing after I made one pull. I knew I could add more timing in even at 10psi, but I guess since it was "dyno tuned" I left well enough alone.

I'll have to change the 180kpa bins, if I try to run too much timing there, it starts to pull ~20% of those numbers at 1bar (14.2-14.9psi). I'll bump 200 down to 190 and 180 down to 170 and see if that helps. I know I can't run more than 15-16 degrees just below 5k at 1bar.

Oh, in the video above;
That was repeated back and forth runs pulling to the top of 3rd and shutting it down before hitting the corn. LJ, we're going to have to work on our production skills a little.

[turbodan]

Nice wheels, BTW

[Brad D.]

What really gets me guys is that when I look at turbo ignition maps the timing at 1 bar is either exactly like mine or only a couple degrees higher/lower. I don't how many people are running 9:1 b35 motors at 15psi and a stock cam, but I thought I'd be able to squeeze more timing out of my low comp. (7.7:1) hybrid. I'm thinking it's cam time.

I have an interesting theory that might explain this. I am wondering what the b35 head on a b34 block/pistons does to the quench and squish of the charge mixture. Since the b35 head has a totally different combustion chamber and relies on its bespoke pistons to make up the compression ratio, I have a feeling that it has a fair amount of quench area at the periphery of the piston. This leads to a lot of additional turbulence in the combustion chamber which makes the engine much more resistant to knock. I can explain why if you like, but for know I'm going to guess that the b35 head reduces quench when installed on a b34 block, adds less energy to the charge mixture and makes it more knock prone.
If you look at any well designed pent roof 4 valve head, you will see large quench pads that have a very small clearance gap with the piston at TDC. This compresses the air out like a jet, creating lots of turbulence and helps the mixture to burn faster, lessening the likelihood of detonation.



Quench pad "built into" the piston.

[T_C_D]

From practical knowledge I do not suspect that the changed squench area makes much difference. I ran a b35 head on a b34 block years ago and the car kicked ass with no detonation issues.

Todd

[turbodan]

Could it be hot spark plugs?

[M. Holtmeier]

NGK bpr6es.

I'm out of the detonation with it. I really think it was some shitty fuel. I've pumped 91 into a couple of times with timing around 16/17 degrees. That's what i was wondering about higher octane fuel. What if the MBT is higher and I just can't get there with 91?

[turbodan]

I've used 7's and 8's. It doesn't seem likely they're causing your problem though.

[Coldswede]

Have you tried running some of the 85% ( I think that's right) Alcohol blends? In your neck of the woods I bet it is common and it might help the detonation. Just a thought

[turbodan]

Shouldn't be necessary, and if there is something going on that would be treating the symptom and not the problem.

[M. Holtmeier]

I took the car to our local 1/8th mile track and got some practice. I must admit this is my 3rd time to a drag strip and it was finally slow enough to get multiple runs in without waiting a half hour in between. It's exactly what I needed to get a feel for the car and the track. Every other car I've owned that has had any kind of power to speak of was an automatic, so negotiating the 5 speed on street tires with 400 ft/lbs was fun. Looking at the numbers, you can tell the car never once "launched." If it didn't wheel hop, which it never does on the street, it would spin the tires all the down the track or I would have to slip the clutch and pedal it in every gear. To compare to some of the other cars, I was trapping higher speeds but was about 1-2 seconds slower! These were trailered in cars with slicks, v-8s and big cams. I will never go to the track again without a set of slicks. Hopefully I can use this post as a reference point on which to improve.

I did manage to break something. On my way home, the Spec stg3 clutch started to slip in 5th under full boost at about 60mph. I think it still has plenty of life left, just didn't think I'd ever go through a 6 puck ceramic in a year. Probably more driver error than the components. I'm really thinking an auto might be better suited for me.



http://s175.photobucket.com/albums/w140 ... 214549.flv