Author Topic: New Turbo thread (Read 7742 times)

Don R · « **on:** November 20, 2021, 04:18:33 pm »

Terry and I thought it might be fun and informative to start a new turbocharger discussion to get some current information here. I'll post some pics of my stuff and the good/bad of what little I've learned.

Don R · « **Reply #1 on:** November 20, 2021, 04:25:24 pm »

I've been watching engine masters on Motor Trend. A couple of the dyno tests shows were testing surpercharger motors with blower cams versus regular cams and blowers on engines with good ports versus smaller ports. What they determined is more boost can overcome weakly flowing heads and stock cams but a good cam and good heads still work on a blower motor.
I'm curious about water/alcohol injection too.
The ATP kit came with an electric fuel pump, in the parts bins I found two tees/wyes that feed the dual petcock into one line. An oil filter housing had three fins removed, I almost tossed it, then wondered if it's to clear the 4-1 spider header. I'm not sure how low it goes.

NitroHunter · « **Reply #2 on:** November 22, 2021, 09:24:25 am »

Don let me tell you my turbo electric fuel pump story. Both the bikes I had with the ATP and Mr. Turbo kits used some tiny pumps, okay for riding around but not so good for real boost. Of course these were street kits.
I had one of those little squares pumps that while the motor was running would intermittently have delivery issues, and try as I would I couldn’t duplicate it on the bench. I did all the normal stuff to check for crap in the tank, petcock, lines, pump inlet, even pumped a full tank through it on the bench with no issues. Hmmm.
The weekend following I drove 5 hours to the Dragbike USA Northwest Nationals to run my new big bore motor looking for a class national record. After a gentle check out pass, I got on it and melted my BRAND NEW custom Arias pistons when at 15lbs of boost the fuel pump took a slow time out. To say I was distraught was an understatement. One of my Funnybike pals showed me his Holley red pump with external pressure regulator, it was typical of the class. I changed my fuel system to match his, the petcock became a 5/16 full flow ball valve with 5/16 suction line. Dedicated power supply. The problems were done, and I felt safe with the stiffer #30 wastegate spring for the next motor. No doubt overkill but as a young guy working overtime to afford racing parts, losing a new big $$ set of pistons-rings-bore and hone and time involved made the peace of mind worthwhile.

Don R · « **Reply #3 on:** November 22, 2021, 11:57:33 am »

Thanks, I was wondering about the tiny 5.5mm hose going to this big fuel pump. Probably a late type gas tank and a full flow valve like a Pingel petcock, but a full flow ball valve would surely get it done and be cheaper.
I got a tank recently that had a pipe thread adapter and a large flare fitting on it.

Old Scrambler · « **Reply #4 on:** November 22, 2021, 12:21:59 pm »

Following

I use 5/16" ball-cocks sourced from Fastenal. Passive research is interesting about comparing lobe-centers for clearing the cylinders vs maximizing fill. Exhaust ID matched to E-valve D seems to promote optimum velocity to Turbo-Inlet. Fuel pump must deliver at maximum RPMs with adequate return and bowl size.

Don R · « **Reply #5 on:** November 22, 2021, 01:34:45 pm »

Like this? L0L!

Don R · « **Reply #6 on:** November 22, 2021, 01:57:54 pm »

This one has the Bendix/Zenith carb often found on a sportster Ironhead. I suspect a big Harley carb might be a good upgrade.

Medyo Bastos · « **Reply #7 on:** November 22, 2021, 02:39:54 pm »

Im going with a hsr40 on a B40

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Don R · « **Reply #8 on:** November 22, 2021, 03:46:21 pm »

Makes sense. Steve said they told him don't go over 10psi with stock rods. He did and they were right. I read B25 could make 25 psi and a B40 can make 40psi. I wonder if that's true?

I'm also wondering if the core bearings are something normally available and if they can be replaced? I tried to buy a new core/turbo from Germany but was a day late and dollar short.

Edit, I found a length of 5/16" gates efi fuel hose. It should do nicely.

NitroHunter · « **Reply #9 on:** November 23, 2021, 09:41:08 am »

My B-25 wastegate spring was never set over 15# with the 850 kit Suzuki but it had no problem hitting that in second gear. The E compressor on the Honda smacked the needle so hard on the 30# gauge stop pin that I thought it would bend. It was awesome. Didn’t matter the motor size, from stock bore 736 to the big 1000 motors. It pumps a lot more air, don’t remember exactly how much more, in the sweet spot on the map it’s like 50% more cfm. I believe I have the maps saved somewhere and I’ll pass them along.
Stock rods in various forms are a recipe for case ventilation. Killed several sets myself - EXCEPT for the one set in the record setting 736cc stock bore motor. Stock rods and pistons that ran down the strip many dozens of times with a best run 10.00 @ 143mph. I’m sure it’s all about the peak cylinder pressure timing, and there are plenty of variables to get wrong and end up with little ‘S’ shaped pieces hanging out of the case. I did my homework, made calculated choices, and got lucky with my total combination and it lived.

Don R · « **Reply #10 on:** November 24, 2021, 04:59:01 pm »

That's the kind of information that can save me/someone a broken something or other.

Don R · « **Reply #11 on:** January 13, 2022, 12:01:23 am »

I saw an ad for a Rajay 301 F90 The guy has two NOS for $425 each. Too big for an 836?

Cb750 Racer · « **Reply #12 on:** January 13, 2022, 10:55:31 am »

Quote from: Don R on January 13, 2022, 12:01:23 am

I saw an ad for a Rajay 301 F90 The guy has two NOS for $425 each. Too big for an 836?

For reference my mr.turbo gpz900r with a big bore kit is running a ff25 rajay and doesn't hit boost until 6000rpm.

Don R · « **Reply #13 on:** January 13, 2022, 04:59:03 pm »

A guy texted me today that has a kz1000 ATP turbo bike for sale, I have not seen pics or prices.

Don R · « **Reply #14 on:** January 18, 2022, 02:36:50 pm »

Update on atp progress.
Luckily, I found the original boost gauge is still made by Wika. 0-30 psi. It doesn't say ATP on the face but all of them didn't have that. I'd like to have a tattle-tale valve on the back to record max pressure in case I'm too busy riding to look.
Apparently, there are shops that can re-build the turbos from the atp kits. The $425 Rajay turbo's I found online are sized for a 5 liter engine so no joy there.

Don R · « **Reply #15 on:** January 20, 2022, 10:35:53 pm »

I've been watching a Steve Morris video on engine building trying to glean a little cam information on a power adder engine. Someone here said the F2 cam was recommended since it had 108* of lobe separation, which I like because I have two of them. Hondaman said they are ground a few degrees retarded in stock cam timing compared to earlier K cams. I'm wondering about setting up the cam in a turbo bike, I'd guess a few degrees advanced (like a K0) to the smog era cam would be correct. I have a couple cam gears that are triple drilled and a couple lightweight stock F gears.

Don R · « **Reply #16 on:** January 21, 2022, 09:47:13 pm »

After watching a load of videos mostly showing off products, I read up a bit and saw a series of dyno pulls on a dohc (hilux) 4 with a turbo, they dyno tested it at 5* increments retarded and advanced. It made the best power with the intake cam straight up in the stock location but 5* advanced was close to that. over 5* either way power fell off.
This old tech turbo may have more exhaust pressure than newer designs. It should respond to earlier opening exhaust valve timing, so I'll advance it a little on the intake to help the exhaust and see if that works.

Don R · « **Reply #17 on:** January 24, 2022, 10:22:27 am »

Wow, after reading the ignition thread I realize how far behind the curve I am. My cars holley efi basically tuned itself and we run locked timing for WOT.
I'm sure I'll leave some power on the table with the old tech turbo and a (Bendix Zenith?) carb, hopefully the a/f ratio gauge and pyrometer will keep me from using up parts.

Don R · « **Reply #18 on:** February 08, 2022, 04:51:00 pm »

If you got the hardware, you need the sticker too! It must be worth at least 10 horsepower.

Don R · « **Reply #19 on:** May 10, 2022, 10:01:20 am »

I watched a few engine masters show dyno tests. What I've seen so far is a blower cam works well even without the blower and a regular performance cam also works well with a blower.
A blown or turbo engine with no intercooler but running E85 can see similar intake temps and power levels compared to an intercooled engine.
A gas normally aspirated EFI engine with water/methanol injection can get lower intake/cylinder head temps and run more timing. The same EFI engine run with just methanol (no water) injected also made more horsepower than the water/methanol mix. My tow vehicle needs this.

BomberMann650 · « **Reply #20 on:** May 10, 2022, 10:41:40 am »

Would this be a good thread to ask questions about carb setup for turbo?

I've picked up some bits about preparing the carb to handle boost. But haven't entirely sorted the information.

Been following a turbo kit maker on the Facebook. Though he doesn't divulge technical secrets.

Don R · « **Reply #21 on:** May 10, 2022, 01:35:20 pm »

This one had a suck through Zenith/Bendix which is still available new because they were original on a few Harley Davidsons. They also can have an adjustable main jet although I'm not sure if mine has it. I have read they are an awful carb but I'm sure every carb has it's haters.
I'd consider efi since they are available for H/D's also and there should be something that fits where the Zenith was. Honestly, this bike will probably be a show queen since bar hopping on a bike has gone out of style.

gpzkat · « **Reply #22 on:** May 26, 2022, 10:39:27 am »

I use a smallish Mikuni HSR42 on my GS1100E, yeah sorry not a Honda, hope OK to jump in. It was the least expensive one I could find for my bike and it's fine, the tuner said I'd find a lot more HP with a 48 but 182 RWHP at 15 lbs boost is plenty. Mine ran an S&S long super B that stuck out in the wind when it raced at Bonneville.

On the HSR I put an extended bowl apparatus on, it wasn't expensive, all together with carb about 250. I have seen this carb used on a Honda but the intake was modified to swing it around forward to clear the frame rails, maybe 30 degrees at a guess.

That S&S carb was FUBAR so I chucked it and sold the air cleaner assy. MPH max was just shy of 184 MPH in 96, I have several slips and plaques from 80s in the 160-175 range. The ATP kit came with a Keihin HD carb that I have read is used as a contest at HD meets, see how far you can throw it....

The question is the fit. My Mikuni is slightly angled and runs fine. I had an electric fuel pump (bracket visible in pic) but the tuner said no need and he ran many dyno runs. No problems on the street. When I got the bike it had a massive plumbing supply ballcock setup with adapter, 3/8" line. I still have that.

The issue I have with the bike is holding on after 7K, I really have to focus as I'm an old guy now. It hits so hard my brain turns to jello. Here are pics, everyone likes pics.

Quote from: Don R on May 10, 2022, 01:35:20 pm

This one had a suck through Zenith/Bendix which is still available new because they were original on a few Harley Davidsons. They also can have an adjustable main jet although I'm not sure if mine has it. I have read they are an awful carb but I'm sure every carb has it's haters.
I'd consider efi since they are available for H/D's also and there should be something that fits where the Zenith was. Honestly, this bike will probably be a show queen since bar hopping on a bike has gone out of style.

Don R · « **Reply #23 on:** May 26, 2022, 11:45:53 am »

I appreciate the carb info, I see cheap S&S carbs and china clones of anything Harley for sale but would prefer a genuine mikuni.
I love that bike, I just keep looking at the pictures.

Don R · « **Reply #24 on:** October 05, 2022, 03:48:30 pm »

I was cleaning the shop today and opened the turbo totes. Thought I'd share a couple pics. The billet intake appears to have a bigger plenum area with no divider in the center like the ATP intakes have. It could use a little port matching inside and a pound or so of excess metal could be milled off the outside.
It would have been so easy to do before it was welded together.

Steve Egli said to be sure to use the spider header, he didn't mention which intake he liked best. The spider has bent flanges, I'll have to make up a fixture to flatten them back out.
Some guys on F/B were interested in the dented turbo header even though someone (not Steve) beat the snot out of it. I'd guess it will take a good tig welder to fix it. I lost track of the F/B post.

I think the Zenith carb has the adjustable main and pilot jet. Seems a little too easy to screw with, good thing I'll have a pyrometer and O2 sensor.

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Author Topic: New Turbo thread (Read 7742 times)