When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I received another piece of the puzzle today. It’s a Forced Performance HD 80/85 T6 turbo. I also called BTR and he is hoping to have bearing spacers in a few weeks. I’m hoping to start machine work on the block by the beginning of the year.
Glad to see you're making progress. I'm curious how you decided on that 80/85 rotor group? It might be a little small for your build. That is, you'll have to wastegate early so as not to overspeed the turbo. If that engine breathes as well as it sounds like it's going to, you could take advantage of larger comp and turbine wheels.
What stroke is that moldex crank? And you said dx...what lifter are you planning on running? I've seen people use the .921 stock rollers, and I happen to have a set of schubeck ceramic .921 flat tappets.
Glad to see you're making progress. I'm curious how you decided on that 80/85 rotor group? It might be a little small for your build. That is, you'll have to wastegate early so as not to overspeed the turbo. If that engine breathes as well as it sounds like it's going to, you could take advantage of larger comp and turbine wheels.
I picked this turbo by doing research on sub 400 ci engines. I wanted something that would spool off the footbrake and be capable of 800 hp. The plan is too get my feet wet with this combination, run dragweek and if I decide to upgrade this turbo will work well in my ls swapped C10.
What stroke is that moldex crank? And you said dx...what lifter are you planning on running? I've seen people use the .921 stock rollers, and I happen to have a set of schubeck ceramic .921 flat tappets.
It is a 3 5/8 inch stroke crank. We have not got to what cam I will use yet. I am thinking about using the solid roller that is in my 461 currently. I plan on calling Bullet cams and talking with them about possible cam specs. My machinist is looking at rod and piston combos to give me a few options. We are shooting for 9:5:1-10:1 compression.
I have experience running a similar turbo on a 325 cube ls motor....T4 flange and same .96 ar. It definitely has backpressure issues coming up on 20 psi....over 2-1 ratio with an open exhaust. I data log backpressure. The last thing you want is a turbine limited unit, good way to start hurting parts. I feel the compression is totally appropriate. Even on pump gas. If this is going to be on race gas or e85, you can pump the compression up even higher in my experience.
what we find, on street motors is that lower compression works better and move forgiving to parts and tune. 8.0 is more forgiving tune than 10 to 1. And if the turbo is only going to support roughly X amount of power anyway, one runs better with street stuff with lower comp and bringing in the boost to compensate. But there are TONS of ways to go and most will get to the same or close results.
MOST of the guys I know on these mild builds, (MILD PARTS WISE) usually make 1000+Hp with 75 mm stuff for street drivers. These are usually 8 second, 3400 lbs or more that are pump gas.
I picked up another block, 4 bolt main caps, and bearing spacers from 68 Post over the weekend. I got them dropped off at the machine shop, they are pretty backed up but he is going to fit me in. I am hoping to have the engine back in April. Until then I will keep working on the headers and hot side turbo piping.
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
Originally Posted by olds80six
What stroke is that moldex crank? And you said dx...what lifter are you planning on running? I've seen people use the .921 stock rollers, and I happen to have a set of schubeck ceramic .921 flat tappets.
If you ever want to sell those lifters, I'm a buyer.......
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
Originally Posted by coppercutlass
See this is why don't come here any more lol. Non sense. Oldsmoboogie there is a guy in your area running a very fast boosted olds ( pro charger ) nice guy but he ain't much on the Internet. I remember when guys told me my engine would blow up. Here I am running 11.50's 200 + 1/4 mile passes and 3k street miles with parts no one would ever use because " why risk it "
Make sure you come on here, I enjoy reading about your NA progression using production parts. Theres some good lessions to be learned from your low buck approach. Not to change the subject, but I did get my NA fuelie headed flat tappet 350 in my truck, you are now looking at my tail lights, you better step it up!
Nice build, looking forward on the progress.
What fuel do you want to use, pumpgas or E85?
Going for 1 or 2 wastegates, intercooled or non-intercooled?
I haven’t decided on fuel yet. I’m leaning towards e85 and non inter cooled. I am waiting to hear back from the machine shop on some piston choices to determine compression ratio. I have 2 waste gates, 1 for each bank.
I haven’t decided on fuel yet. I’m leaning towards e85 and non inter cooled. I am waiting to hear back from the machine shop on some piston choices to determine compression ratio. I have 2 waste gates, 1 for each bank.
What is your final bore size ? If he has it cleaned and machined lets see those block pics !
I haven’t decided on fuel yet. I’m leaning towards e85 and non inter cooled. I am waiting to hear back from the machine shop on some piston choices to determine compression ratio. I have 2 waste gates, 1 for each bank.
That should be a good and clean set up. Turbo in the middle in front of the engine with the charge tube directly to the throttlebody.
What EFI do you want to use? 8 injectors in the manifold or just a throttle body EFI like the 1200HP (=800HP on E85) from FiTech of Snipper?
2 wastegates sounds like more then enough to control the boost.
I will most likely use an elbow and ls style throttle body with injectors in the intake. I have some 3/16’s aluminum sheet so I am going to talk to my buddy about building a sheet metal intake similar to the Holley low ram intakes. It all depends on how busy he is and what he will charge for it. If he can do it for 1,000 or less I will go that route.
Cool project! Boost is very addictive. There has been a lot of great advice already so I don’t have much to add... with turbos the easy part is making the power, the hard part is making the trans, rear ends, etc all live.
A few updates to post, unfortunately i have not heard back from the machine shop in a while. I am hoping to have the engine back by the end of April, I know he is swamped so I am trying to not bug him. I did get a Victor intake, Summit has them again. I got the passenger manifold tacked up and turbo placement figured out. I am fitting and tacking everything and my buddy that is a pipe fitter is going to weld everything together. I am going to convert to a manual rack to eliminate the steering box and pump. I will need to figure out a passenger side alternator set up.
That is looking good!!
Do you want to make a support bracket for the turbocharger (like the V8TV build) or have the complete weight of the turbo on the manifold?
Take your time to get everything positioned correctly, install all the components like radiator, alternator, etc. before starting on the pipe routing.
The wastegates can become a bit difficult sometimes but it depends on if you want to have them open or routed back into the exhaust system.
On my racecar I moved the alternator from the passenger to the driver side and changed it to a small 40A unit from a Kubota digger.
Last edited by Altered 1978 350 Olds; March 27th, 2023 at 12:29 AM.
Some more mock up picks. I have a brace on the flange temporarily. I will be using a Maven mount attaching the turbo to the block. Driver side is up next.
Some more mock up picks. I have a brace on the flange temporarily. I will be using a Maven mount attaching the turbo to the block. Driver side is up next.
I stopped by the machine shop this week and they have not started on the machine yet unfortunately. I did get the manual rack installed though. Now I can finish the drivers side header and hot side mock up.
When i installed a torq storm SC on my BBO i used a stock trans am (403) alternator mount and pullies that puts it near the middle right side front of block and the belts worked.
November 30th, 2022, 04:05 PM
