Turbo 3800 blazer

MikeRenz

not stock
Re: Turbo 3800 blazer

What do you think happened? I can see/hear a complete lift of throttle after the pass prior to the entry of the turn, and surmised "drop-throttle over-steer". But that's not what it did. It under-steered, but not really that either. I don't see the front wheels turn into the turn like I would expect them to do with an under-steer event. It just goes left off the track. After the pass, you were definitely left of the line you followed on preceding laps. Could it be you got into an area of the track that wasn't as good holding as the "line" portion? It just went left.

looked like he just entered the turn too hot and outside...from passing the car just before entering the turn. He just took too long to pass the car, and didn't brake soon enough.
 

sytyguy

Moderated User
Re: Turbo 3800 blazer

Windows down in road racing and solo II.
Not entirely true. SOLO II does not require windows to be down when racing.....in fact, they do not dictate one way or the other (up or down) even when referring to convertibles. There *was* a rule decades ago that required convertible tops be down when racing, but no more. Each region does have some injection of it's own rules and requirements (sometimes due to insurance and site requirements), but the SCCA has no blanket rule on the matter. Many SOLO racers will roll the windows down to lower the CG, but that is the racer's choice.

As far as road racing, again it differs with organizations and tracks. NASA used to allow us to run them up or down at Roebling, but required them down at Road Atlanta. This was due to signaling and not from a safety standpoint. Most tracks that have adequate worker stations and can blue flag in lieu of signaling will allow some flexibility on the matter. Other tracks don't want to bother with shattered glass if cars trade paint or slam a barrier....so they require them down. And in some cases (speed runs, track rentals, etc...) the track will allow them up regardless of rules to allow the car aero to benefit (this can be the case at Roebling from time to time as they have a nice, long front straight.

The conclusion? There is no blanket rule and it is often the discretion of the governing body or track that the race is conducted at.
 

Typhoon#747

Donating Member
Re: Turbo 3800 blazer

Hey Michael, I don't know what the "requirement" is in Solo II. But, I've never seen anyone run with their windows up in an Atlanta region solo event since I started going in 1997ish. Most of these events are held in warmer weather and nobody races with their AC on. And like you said, nobody likes a face full of glass pebbles!
 

sytyguy

Moderated User
Re: Turbo 3800 blazer

I've never seen anyone run with their windows up in an Atlanta region solo....

Neither have I. Your original comment made it sound as if you were saying it was a requirement. I was just reiterating that it's not and that it's up to the specific track/governing body. I have seen many people (and personally have) run with their windows up at our pre-year test-n-tune at Hutchinson Island for the Bucc Region. It's held in January and is often as cold as nuts.....so windows up for all of us out there.

FWIW, I run SOLO in the ATL region several times a year (and sometimes head up to Chattanooga)....we'll have to hookup one day.
 

BMFB

Not to scale
Re: Turbo 3800 blazer

Yea I just goofed that corner coming in too hot.

If you watch the vid, I think its the lap before I flip, I take a super weird line coming through that same corner. That vw that was in front of me pointed me by to pass him, but when he did he lost control of his car in the straight and went off the track kinda next to me. I thought it was funny.

Window down was not a req but I opted to do it so I could signal to people easier. The breeze is nice too. When it flipped it happened fast and I didnt have time/forethought to cross my arms. I deathgripped the wheel I think, luckly it wasnt be enough to break my thumbs.

I shut the truck off as soon as I realized we were stopped (pretty fast in the vid). I then listened for fires...
 

BMFB

Not to scale
Re: Turbo 3800 blazer

Yea they are the generals.

I decided that the flush look was not going to work for winter. To lift the front I was froced to modify my lower control arm mount.

I used a piece of 2 inch square stock, cut to about 3 inches. I drilled a hole (simular to the original mount) and cut one said of it off (so that it looked like a U instead of a square) so that the shock could be removed.

This is something I have actually wanted to do for some time, as the suspension doesnt really like being THAT low. It was so low that the lower control arms were slightly higher at the ball joint end than at the mounting end, which is bad for the geometry. My goal (for racing) is to have it at rest with the ball joint and the mounting bushings at the same height when it is at rest.

Lifting the back was done with shackles. I may lift it more still in the back...not sure yet.

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It snowed about .25 inches last night which was just enough to give it a try. First off its weird getting into it now back its so much taller than it was. Its also feels like a truck again. The tires are excillent from what I could tell in the tiny amount of snow. I am happy thus far.

I will try to get some pics up of how I modified the shock mounts. I will also showcase my obviously damaged rear axle mounts. Could be the frame, springs, or something else. Either way my rear axle sticks out of one side of the truck about .75 inches farther than the other.
 

BMFB

Not to scale
Re: Turbo 3800 blazer

1.

2. I decided to put new valve springs in. I took no footage of it. I went from a 130# to 150# at rest spring. at full lift though its about 1/3 more spring tension. It seems better but its all ice.

3. They knocked down the Genesee towers.

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BMFB

Not to scale
Re: Turbo 3800 blazer

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Figured out my he'd gaskets been leaking all year. Dealing with it.
 

neildemo

Administrator
Re: Turbo 3800 blazer

Brian, I have heard from a few people that the 3800 can't handle nearly as much boost as the 4.3.
What are your thoughts? have heard its because of the headbolt pattern.
 

BMFB

Not to scale
Re: Turbo 3800 blazer

well, lets do this

As far as 'boost' goes, its not an easily direct thing to compare. As far as just air pressure going into the motor goes, its actually all very dependent on the individual setup. Turbo inefficiencies, head flow, blah blah, boost pressures don't matter. But, if I took this turbo off my 3800 and put it on my 4.3 I don't think it would last at 28 psi.

So the real measurement is output of the motor, or horsepower. I like to measure in averages rather than peaks myself. I actually prefer using a 1/4 mile hp calculator to get an idea of how things work. Although they aren't going to line up against a real dyno, they are a good way to figure out where you stand relative to something else.

[There's a whole argument to be made against what an in floor dyno really tells you as well. I.e. if their so accurate why can do you go to three different dynos and get three totally different numbers, but that's another rant.]

Personally I go by what happens in the quarter mile. More specifically the MPH vs. weight.

So i'm going to treat the question as a "what would make more hp on the same turbo, a 3800 or a 4.3?" I'm also assuming that you are talking about an equally modified 4.3 vs. 3800.

For the 'average guy' with a budget of motor under 2 grand there is no other motor that can take what a 3800 can. I can only go off of what my builds and experiences are, and my 3800 build is (with prices)

stock series 2 L67 3800 ($150) from junk yard with:
statamma 5 cam ($300)
arp head studs ($80)
mls gaskets ($130)
double timing chain ($200)
PAC valve springs ($200)

total cost is about a grand with all the misc gaskets and shit I guess.

This 3700lb awd truck has gone 11.005 @135 (best mph #28psi) and 10.50@127 (best et(@20) I had a hard time launching at the beginning of the year. Last time I went to the track and had it down I blew a coupler when I went for my 28psi run with a good launch.

If I did those same changes to my typhoon and threw the same turbo on it id be a happy man living in the high 11's before catastrophe.

The trick really isn't in the head sealing abilities. Both do pretty well, and truth be told a good set of gaskets will hold against alot with some good studs, no knock, and good timing (same can be said for pistons too).

I blew my head gasket back in July when my Gatorade bottle burst at wot going down the track and my turbo ingested the coolant. I drove it with this blown gasket up until yesterday, and that 10.50 was run with said blown gasket (that Gatorade bottle is still the worst thing Ive done to my truck). The real fuse is the bottom end. What can the crank take before it starts twisting, warping, or otherwise distorting or just straight blowing itself out of the oil pan. In this respect the 4.3 is terrible in comparison to the 3800.

A decently build turbo 350 chevy with 4 bolt mains, decent rods/pistons and heads with a turbo is working hard to make 800 hp to the crank. Cut 2 cylinders off that and see where the 4.3 stands. My 3800, dragging my 3700 lb awd truck through the traps at 135mph...with a guessed drivetrain loss of 25% (guessed from Alex's experience) is making approx 840 crank hp with 1/3 less displacement.

So keeping in mind you can build one banaza 4.3 and out do a 3800 by alot, but stock for stock, or even with some reasonable dollar budget I would side with the 3800.
 

BMFB

Not to scale
Re: Turbo 3800 blazer

intake gaskets/rockers/pizza

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head
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gaskets
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super straight deck checking thing I bought, new vibrant exhuast vibration isolators
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turbo
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new turbo mount poorly pictured, with vibration thing. head reinstalled.
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Seems to be running alright, I need to pull the oil out of it and see how its looking but all seems well so far.
 

dgoodhue

BuSTeD 4.3
Re: Turbo 3800 blazer

A built 4.3 Chevy V6 short block (forged pistons/rods, splayed 4 bolt mains, block filler) is pushing the limits when pushed past 700hp. A factory 3800 that is making over 800hp is clearly out performing a 4.3L V6. My guess is that 500hp is probably pushing limits on a factory 4.3
 
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