Finally back up and running again...Latest update on my setup...

[FJM568]

After a long hibernation period, my 85 GN with the custom intake setup is back running again...

After running it and driving it on the highway briefly, I now am starting to remember some other nagging problems that my setup has and more reasons why I was trying to convince people that it isn't worth the time and shouldn't be duplicated UNTIL I figure out all the bugs...I have an extreme amount of lag with the setup...I need to figure out what the heck is going on and I have an idea of what it might be...Although I think that if I had a F.A.S.T. system, I could tune it out with that...Not sure if I can tune it out with the stock ecm setup though...I probably need to do some more research on that one, though...I do still have some bad exhaust leaks now, but when the car was running before, I had pretty much no exh leaks but still had a lot of lag...I will finish sealing up the leaks this week and will dig into the lag problem farther, along with a possible cure(design change on my intake setup slightly) to try to fix the lag...I WILL eventually solve this problem, but for now, it is tricky to drive because it bogs so bad from a dead stop that it will stall if I don't feather the throttle...

Last year when it was running, I had it at the track and even with powerbraking off the line, I was still only able to get 2.6-2.7 60' times with no wheelspin and slow boost buildup...But once boost built up and the rpms came up, it shot right up...

Right now with the way my intake is set up, I have an extremely LARGE plenum volume, like 6' worth of 2.5" dia IC tubing and a CAS V2 FMIC along with the 87 lower intake volume...I have a feeling that I'm going to have to reduce that by a little bit(Some of you may already know what I am going to try)...I hate to do it, due to the downsides involved with it, but it may be unavoidable...

Oh well, I'll keep you all updated as I find stuff out...

 

[WFO]

hey jim,list your combo again for me,just the basics.

i'm thinking a 16 pos maxeffort is in your future...

 

[FJM568]

109 block, steel center mains, .030 over TRW forged pistons, David Chase's Stage JR heads(no egr or heat crossover), CC 206/206 cam, TA-51 w/PTE exh housing, MSD 50# injs, 3" THDP prototype for the hotair setup, CAS V2 FMIC, 87 lower intake w/custom upper plenum to run the turbo in stock 85 location, Neil Chance 2800 stall LU TC, Type 2 coil pack, 87 ecm, Imp SS MAF and Translator(not the plus), Poston's headers and crossover, and probably some other stuff that I'm forgetting...

The MaxEffort would probably work decent with the Translator+(gives some fueling and spark adjustment)...But I think that I'm really going to have to get a SFI F.A.S.T. setup w/ind inj control so that I can even out the cyl distribution...With the way my intake is set up, I have no idea what the cyl distribution is like...Who knows, I may have even air distribution between cyls right now, but I wouldn't know it...

Oh well...That's what I've got, and I'm now remembering just what a headache this setup was...

 

[TurboRegal84]

Another "fast" Hot-Air

Originally posted by FJM568

But once boost built up and the rpms came up, it shot right up...

Great Jim...The last thing we need is another Hot-Air running a 15.0 @ 107MPH


Please keep us updated on the Combo...Im sure once everything is worked out you will lay down some real nice numbers!

 

[FJM568]

Had it dyno'd last year before the #3 exh cam lobe went flat, and got 330hp/440tq on 92 oct pump gas at 16# boost...

And it went more like 13.8 @ 108 or something with the same settings as on the dyno...

So Herb, your quess was only like a second off!!!

But I guarantee, there is a heckuva lot more in this motor!!!

 

[TType85]

Is your throttle body still on the turbo?

The one thing Jay @ Turbomotion went through with the V2 setup is that when the TB was still on the turbo the lag was TERRIBLE and that was with ALOT less IC pipe than you have. Move the TB to the intake and I bet the lag goes away....

 

[Zacks 85GN]

Intake

Jim,

Now that I am not going to be getting my turbomotion kit back, I am at a loss as what to do. Thinking of converting over to an 86/87 setup. I was at a place where they sell used race car parts from Winston cup the other day and found some Buick V6 parts. They had an intake where the carb flange was moved foward and at an angle. They also had stage II intakes as well but the other one needs a closer look as the turbo may clear better with its flange location. Keep us posted and good luck.


Note: This place had some Indy Buick cylinder heads along with stage II cranks, heads,cams, front covers,roller rockers and more.


Jim Willett

 

[FJM568]

The Indy heads won't work with our motors...You may want to post over in the Stage forum of this BB for more info...

As for the carbed intakes...That is a definate possibility as long as the intakes are for the off-center blocks...There are right-angle adapters to mount throttle bodies to the carbed intakes...I think some of the Stage motor guys run them...I really hadn't thought of that one...Also those intakes are single planes as well and should be able to work fairly well...IF THE TURBO WOULD STILL FIT ON TOP OF THE MOTOR...

As for my motor...That is the problem right now...I went to U-Wrench-It yesterday and picked up a throttle body from a fwd 86 3.8L motor...Now I just need to figure out how to mount it securely with the way my setup is...This may take some tricky engineering to do...

But I'm gonna try it...

I also thought of trying to put a stock turbo(86/7) back on to see if the lag will go away, just to make sure that it is the turbo and not something else mechanically wrong with the motor...I really do think that it is the turbo that is too big and causing too much lag with the throttle body mounted to the turbo...I'm going to hate to move the throttle body though...There are some advantages to having it mounted on the turbo...

Oh well...Back to the drawing board!!!

 

[6SENSE]

I remember a while ago hearing about using the Edelbrock .231 intake and adapting it to our hotair setups. Definate flow increases.

 

[YNOVATE]

FJM---were you happy with the poston headers you got??
when they sent my mine I thought the welds were way to big...lots of restriction in the ports. I didn't think they looked any better than stock.

I'm just asking in case I got a defective pair.

I haven't installed them.

 

[FJM568]

They were probably as you described yours to be...IMO, they can't be any worse than the stockers that I had on there...My driver's side stocker was repaired at least twice and the pass side at least once, and were probably going to need to be redone anyway, so at that point, anything was an improvement...

I don't really like the 2 piece crossover...I have never really been able to get the darn things to seal to the headers very good, but that is one of the things that I'm hoping to fix on this round of repairs/modifications that I'm going through right now...

I don't seem to remember any welds on the outside of the header tubes where it connects to the header flange...If you want to spend the extra time to do it, I would have it welded on the outside of the flange and then grind the welds on the inside and have the flange flycut(or re-surfaced) to true up the mounting surface, but by welding, you have the possibility of everything "moving" and the crossover and up-pipe not being located in the proper locations for sealing again...

The other thing that I would re-do if I had to take my header's off of the car for any reason, is what I described above...Re-surface the header flanges to true them up again...Just so I wouldn't have to use the copper exhaust manifold gaskets anymore...I'm still not entirely sure that they are sealing properly at the heads right now...I will find out more once I get the crossover to seal right and my up-pipe to seal up...Cross your fingers, I am going to try to weld up my own up-pipe...Using the 87 lower intake kind of relocates the turbo location slightly closer to the passenger side of the vehicle...The intake casting flange on the passenger side is at a different thickness and angle than the 84/5 intake is, which ends up moving the turbo slightly...My current up-pipe doesn't fit properly and I've tried to use a lead exhaust "donut" similar to the ones that are used on the stock 84/5 downpipes to space the up-pipe enough to seal at the exhaust manifold, but I still have a leak there as well...I'm going to try to make another up-pipe and will be mounting an EGT probe there as well as a WB O2 sensor bung for the DIY-WB O2 that I plan on putting together at some point...

 

[cool 84]

Move the TB to the pressure side and your lag and hesitation problems will be gone. You want it as close to the intake manifold as possible. I had the same problems at first and I figured it out that the fuel gets there before the air to cause the hesitation and the lag is from restrictive TB being before the turbo. The plenum volume along with the volume of the IC and plumbing has little to no effect on lag. Mine with the TA49 spooled like a stocker with 3" plumbing and the Ford FM IC.

I still have some of the E-mail from Dave Schmucker when he was involved with the TM IC kit asking how I solved the hesitation issues. When they moved the TB they got the same results as me.

 

[FJM568]

I'm not going to debate the issue...I will be moving my throttle body...The question I have is, How can the 84/5 throttle body be more restrictive when it is larger than the 86/7 throttle body??? I'm going to have to use the 86/7 throttle body(actually one off of an 86 fwd 3.8L motor), since the size of the 84/5 throttle body would be a major problem getting it to fit where I need to put it, but, hmmm...Need to think about this some more about if I could possibly use the 84/5 TB...

 

[cool 84]

I've been running mine with the 84 TB on the pressure side for 2 years now but the 86-87 would be a much easier fit. I used the original only because I couldn't afford a used 87 at the time and it was already bored to 62mm. Not sure of the exact sizes but are you sure the 87 TB is smaller than the necked down section of the 84 TB? Either way it's easier to blow through the TB than to suck through. Plus with the TB being before the turbo you increase the pressure ratio resulting in slower spool and higher discharge temps. My car felt like a completely different car once I moved the TB, much more like an 86-87 car. Full boost came in MUCH sooner.

 

[TurboRegal84]

The 84/85 Throttle body can be opened a good amount. Where it "necks down" you can open that area up to 58mm, and bell mouth the lip so that it isn't that drastic.



I still run the stock set-up, but when I polished and ported my stock throttle body the spool up, and throttle response were improved...Sometimes its the little things that count!

About the Poston headers. Looking into the header from the exhaust flange they look very restritive, and that is because (what Jim said) the weld is on the inside. The Poston headers have a much better design then the stock ones. If you put the 2 side by side you can see the tubes are larger, and where all of the gas collects to go up into the up-pipe is a good deal larger. I saw a half second gain the the 1/4 and better spoolup......These Hot-Air cars react VERY well to Exhaust modifications!

 

[FJM568]

Well, with the stock air inlet tube from the MAF to the TB on the 84/5s, the tube ID is 3", which makes the ID of the TB roughly say 1/4" less, so say about 2.75", which is close to 70 mm, and if it's smaller than that, than you could easily open it up to 70 mm...The 86/7 inlet tube from the stock IC is a 2.5 OD tube, connected to the TB with a 2.5" ID silicone hose with hose clamps...Which subtracting at least a 1/4" from that, you get 2.25", which is about 57 mm...

All the above numbers I am pulling out of thin air...I WILL look into this either later this evening or tomorrow, depending on whether I can dig out my 87 T motor's parts to measure the 87 TB tonight...Now, unless you have a 3" inlet on your intake to make use of the bigger TB, you probably are creating a slight bottleneck at your TB where it necks down to your intake inlet...You may actually see some slight increase by going to a smaller TB with your setup, cool 84, than using your 84 TB...

From the info that I have gotten from asking around, the fwd 86/7 3.8L throttle bodies are the same as the 86/7 TR 3.8L throttle bodies with the exception of throttle blade shaft seals on the 86/7 TR throttle bodies, which our 84/5 TR throttle bodies don't have either, since they weren't designed to be pressurized like the 86/7 TR TB's...

Oh well, now you got me wondering...I'm off to dig up my 87 T's TB to compare...Will report back in later this evening...

 

[cool 84]

I have all 3" plumbing from the turbo to the intake. The only place it necks down is the TB and then it's back to 3" into the intake. I think the TB is maxed out at 62mm considering some metal had to be added to make it that size. The throttle blade might be close to 70mm but it necks down to something like 52mm stock. Regardless of why, the car was like a different car after the conversion and it definately had more power. There's a reason they moved the TB to the intake and pressure side on the IC cars. With the new combo I'm thinking of going with a 70mm TB for the IC cars to keep it 3" the whole way but not sure if it would be worth the very small (if any) gains.

 

[FJM568]

Cool 84, you may check with Jay Jackson, who modifies the stock 86/7 throttle bodies bigger...He may be able to open your 84 TB out to 70 mm relatively easily, and possibly bigger than 70mm...There is a LOT of meat in the 84/5 TB's to do that, and it would be a helluva lot cheaper than buying a new 70mm TB...

I just went and checked the bore sizes of the two TB's that I have...I wasn't able to get to my 87 T's TB, but I checked the one from the fwd 3.8L motor that I have...Here are the bore dimensions in front of the throttle plate...

86/7 fwd TB is about 2.340 and it necks down to about 2.310 at the mounting flange...

My 85 TB measures about 2.650 in front of the throttle plate, but since it's mounted on the turbo right now, I can't get a measurement at the smallest point near the mounting flange...It seems like it is just excess material there and it should be able to be hogged out straight through...Haven't looked that close, but I will as soon as I pull the TB off the car...

As you can see, the 85 TB in front of the throttle blade is about .300 dia bigger than the 86/7 TB...


Cool 84, refresh my memory a little...Just where is your TB mounted??? Do you have any pics that you could email me of your setup???

On a side note, I *think* I have figured out a fairly simple way of mounting my fwd TB on the pressure side of my setup...I just need to have a tube tig'd to a plate, then I need to figure out how to hook up the accelerator and TV cable, and re-plumb the vacuum and pcv lines to the TB... <sigh> It's always something, isn't it???

 

[6SENSE]

Dont exactly remember what it is with the configuration of the 84/85 TB but I know that it is not possible to bore it straight through. That is what I was expecting to do when I had mine off. I was able to take quite a bit of material out of both sides though. Dont remember what the measurements are now, but I will have to take the thing off again anyway. Apparently I took so much out that now the gasket between the turbo and TB is too small! Oops, I forgot about that. It took me a few seconds to realize what the heck that was when I was looking into the TB while holding the blade open a few weeks ago!

P.S. I think the deal with not being able to bore the thing straight through is that if you look from the outside of the TB you can see that its not just the inside of the thing that tapers, the whole thing is basically two pieces, two different sizes. So there isnt enough material in there (turbo side) to open as big as the other side. I have a couple extras sitting around, need to just take a look I guess, to refresh my memory.

 

[cool 84]

Don't know if this will work. http://www.turbobuick.com/forums/showthread.php?s=&threadid=20784&highlight=Pictures

Most of the good pictures are gone but there's one that shows the basic setup. The inlet pipe goes directly to the turbo, the TB is connected with a silicone hose to the 3" elbow going into the intake manifold.