Author Topic: How to build a 2.0l G/BGMR  (Read 15839 times)

0 Members and 1 Guest are viewing this topic.

Offline Wicked6

  • New folks
  • Posts: 26
How to build a 2.0l G/BGMR
« on: December 05, 2018, 12:47:35 AM »
Wicked 6 is a collection of Hot Rod builders in the Vancouver BC area. We are just starting out on a build using a Cobalt 2.0 litre mechanically supercharged engine , T56 transmission. The body is a Fg 27 T. We are using a Track T nose, 2x4x 1/8 basic frame with 1 5/8 seamless tube x 1/8 wall roll bar and ladder frame.
The intent is to get 4 of us into the 150mph club. Most of us have been that fast or almost in drag cars or high performance cars. We were going to build a belly tank but the time restraints on the build, we want to run in 2019, made us change direction. We also intend to street this after we get sick of straightline.
I wanted to put some pics up but all my phone pics are too big.
They will be coming later.
We are at 112” WB, our front and rear suspension is basic hot rod, split wishbones, buggy spring front, coil over rear. We were going to use a Speedway Eng. Midget QC, but are now going with a 9” Ford. We have 3 centres that we can set up Ceuta diff. Ratios and spools.
The 1949/50 Navarro roadster was our inspiration.
Feel free to offer suggestions and/or advice.
I started with nothing, I have most of it left.

Offline sabat

  • Hero Member
  • *****
  • Posts: 1533
Re: How to build a 2.0l G/BGMR
« Reply #1 on: December 05, 2018, 09:06:28 AM »
Consider a contingency plan in case this doesn't happen:

"after we get sick of straightline"

good luck  :-D

Offline Stainless1

  • Administrator
  • Hero Member
  • ***
  • Posts: 8948
  • Robert W. P. "Stainless" Steele
Re: How to build a 2.0l G/BGMR
« Reply #2 on: December 05, 2018, 09:35:14 AM »
Consider a contingency plan in case this doesn't happen:

"after we get sick of straightline"

good luck  :-D

Well let's break this down... If you go as fast as you can in the 150 club (159.99) in 2 1/4 miles you are less than 27 MPH from the record.  My guess is one of you will break out of the club limit if you are not careful.  So while you are building, you might want to keep your eye on the LSR rules and what it will take to make the car compliant... which means it may not end up being a street car... and you will get another 3/4 mile of WOT to play with.    :-D :-D :-D
Have fun with your project, build it to be safe and go fast  :cheers:
Stainless
Red Hat 228.039, 2001, 65ci, Bockscar Lakester #1000 with a little N2O

Offline Stan Back

  • Hero Member
  • *****
  • Posts: 5879
Re: How to build a 2.0l G/BGMR
« Reply #3 on: December 05, 2018, 11:58:05 AM »
Good advice – build a cage to SCTA specs.  Nothing says it can't be removable.
Past (Only) Member of the San Berdoo Roadsters -- "California's Most-Exclusive Roadster Club" -- 19 Years of Bonneville and/or El Mirage Street Roadster Records

Offline Wicked6

  • New folks
  • Posts: 26
Re: How to build a 2.0l G/BGMR
« Reply #4 on: December 05, 2018, 01:01:57 PM »
Thanks for the replies. Getting to post pics here is more of a problem for me right now.
I'm hoping that you guys can answer a few ?'s
do you run an engine cooling radiator, or recirculating water tank?
is an engine plate/firewall a good idea with solid front engine mounts?
what would be an expected weight goal for this class?
We are not complete amateurs to car construction, I have built Midget frames from 4140, 1/4 midgets from 4140, rebuilt a couple of rag and tube Pipers, so tube construction isn't a big concern, it is all the peculiarities to a Bonneville/ElMirage car that is foreign to us at the moment.
Help and advice is both requested and appreciated.
Pat
I started with nothing, I have most of it left.

Offline RichFox

  • Hero Member
  • *****
  • Posts: 2663
Re: How to build a 2.0l G/BGMR
« Reply #5 on: December 05, 2018, 03:52:35 PM »
I used a recirculating tank. Some say put a heat exchanger in the tank and run hoses from the engine through the heat exchanger. I thought on my unblown engine that was overkill. Your experience may vary. Air to water is aero drag.  My G/GR weighed 1650.

Offline 4-barrel Mike

  • Hero Member
  • *****
  • Posts: 3173
  • Any fool can drive a V8
Re: How to build a 2.0l G/BGMR
« Reply #6 on: December 05, 2018, 04:45:16 PM »
Good advice – build a cage to SCTA specs.  Nothing says it can't be removable.

Taken from the web, circa 2006:

Mike Kelly - PROUD owner of the V4F that powered the #1931 VGC to a 82.803 mph record in 2008!

Offline Wicked6

  • New folks
  • Posts: 26
Re: How to build a 2.0l G/BGMR
« Reply #7 on: December 05, 2018, 06:30:00 PM »
Thanks for the pics, and the info re water cooling. We have a water to air inter cooler that we will want to add an ice cooler to.
I started with nothing, I have most of it left.

Offline JimL

  • Sr. Member
  • ****
  • Posts: 799
Re: How to build a 2.0l G/BGMR
« Reply #8 on: December 06, 2018, 11:30:02 AM »
I agree you should build to the SCTA book.  We ran a basically stock 3S-GTE celica engine back in 1998.  I had a 177+ 2 1/4 time slip with a hole in one piston (made the record that year with a coasting through average of 168).

At fairly low boost, Dan put the record at 181 in 2000 (with a best mile at 186 and we kept the boost down to keep from breaking our last engine).

The fellows with plenty of experience told us that "about 275 HP will get you the first 175 mph in a decent mod roadster".  They were exactly right.

It sure gets a lot harder reaching toward 200 and we never made it.

If it was me, I would build the wheelbase out to make room for all the stuff you need to get in there.  The reality is that a few times on the salt and you will have enough corrosion started to need a rebuild on the car should you want to make a street rod.  We started out with a little suspension, had handling trouble, got good and welcome advice from Mike Cook and solved that problem by going rigid at all 4 corners.

That's the basics of the car that held that class record for 10 years or so.  You could certainly build a successful project and spend less money and time than a compromise would require.

Just my two cents.

JimL

Offline Wicked6

  • New folks
  • Posts: 26
Re: How to build a 2.0l G/BGMR
« Reply #9 on: December 06, 2018, 01:26:48 PM »
All the stuff we need to get in there is the question hardest to answer at the moment. We’re not running dry sump, but we need the water cooling, gas tank, battery, fire extinguisher, and most likely a cooling system for a remote intercooler. The engine has a water cooled intercooler in the intake manifold that we can route the water through some ice water cooling tank system, I’m thinking. We were at one point thinking of solid rear and sprung front, but it was suggested by another racer that we would be best running suspension both ends. I guess we don’t need a lot of movement, so very stiff spring rates may be our best bet. Yes, no?
I started with nothing, I have most of it left.

Offline Rex Schimmer

  • Hero Member
  • *****
  • Posts: 2625
  • Only time and money prevent completion!
Re: How to build a 2.0l G/BGMR
« Reply #10 on: December 06, 2018, 03:51:57 PM »
I would suggest using fairly soft springs for the rear axle as this give you the best traction and limit the travel to around 1-2 inches. My son and I run a small lakester and we run about 100# springs on the rear shocks, we set the ride height where we want and then set up the shock with a fairly soft snubber around the shock shaft and set the shock travel at 1 to 1 1/2 inchs to the snubber. This keeps us from bottoming but provides a very compliant rear axle travel that sticks to the track. The salt is basically pretty flat but some years, 2017, it can have some pot holes that make suspension a good idea. Solidly suspended cars with any kind of HP literally bound from one pot hole to the next and there is not much traction when the tires are in the air.

Rex
Schimmer and Son IF/L 984
Rex

Not much matters and the rest doesn't matter at all.

Offline JimL

  • Sr. Member
  • ****
  • Posts: 799
Re: How to build a 2.0l G/BGMR
« Reply #11 on: December 06, 2018, 08:29:14 PM »
Just thinking out loud, here.....one of the tough parts of the 27T body build is getting the driver down as deep as possible, keeping in mind that the foot-floor cannot be below the bottom of the body line.  That driver area is very narrow after you get cage tubes inside the body, and the driveshaft is now extremely close to the drivers seat.  Building for rear suspension travel means either compromising the drivers position (and cage height sticking in the air) or raising the car high enough to allow that driveshaft to have up and down movement without hitting the driver.  In addition, you need enough room to shield the drivers hip and kidneys from an exploded U-joint.

We were warned about that by many successful builders and so decided not to amplify the problem by letting the rear u-joint move up and down.  Mod Roadsters can have the drivers back all the way to the rear axle transverse center-line, which puts the nose of the diff right where you would really like to have that space for the drivers anatomy.

Keep in mind that the engine/trans will be sitting higher than you expected, which means the front end of the driveshaft is pretty high compared to the drivers bottom position.  We actually used a Toyota diff with "offset to the right pinion", and mounted the engine/trans to the right to gain what we could.  We also pushed the engine forward to gain a little more room in the cockpit for that intercooler tank.  Doing that step also simplified the firewall and left more available firewall area to make good, fire protected pass-throughs for all those water lines.  27T doesn't have much firewall area to play with.

The solid rear axle mounting made it easy to set up the rear brake components and have enough looped flexline length to be able to pull the wheel/axle/backing plate packages far enough to swap out differentials without complete teardown or opening the brake fluid lines.  It also left good room for the parachute pull-point mounting. 

Jim Deist instructed us to put the pull-point height (at the back of the body) on the line of a string pulled from the vehicle true CG, 35 feet back with the end of the string 7 feet above the ground.  That worked perfect, over the years.  If you don't build to go fast enough to use a chute, you will be missing out on some of the fun!  It is soooo cool to feel that chute grab your car....you'll like it every time.

I don't think the traction advantage of rear suspension will overcome the added aero drag of putting the driver and cage too high out of the body.  Those round tube roll cages have ferocious aero drag, and this becomes a case of "less = more" by minimizing that exposed height.  You can't do much about those open wheels hanging in the air, so the only aero you can improve on inexpensively is total frontal area.  We all pretty much use the same body....it's the cage and windscreen choices that have the biggest effect when you start going fast.  Get that driver as deep as you can, within the rules....and then you build from there.

Re: tanks....we ran a water to water intercooler tank just to the right of the drivers legs, and a 16 gallon cooling tank in the right side of the cockpit cage area.  We used heavy sheet metal shield around that big tank, which was great that day at '99 Speedweek when the boost ran away, blew the head gasket and torched away parts of the head and block, and exploded the water connections into the cockpit tank.

The true cause of that mess was the necessity to solid mount the engine...which vibrated apart some linkage.  It's always some dumb little thing that makes the biggest problems.

Over my years on the salt, it seems to me that if the salt is so rough that you need suspension....it will probably not let you get up to a well established record.  The better years make a big difference, because a lot of the good records were set on decent salt.  That just seems to be the way it goes, and it doesn't go as well..... as time has gone by.  My first Speedweek was wonderful salt, all week, back in 1969.

.....sorry folks....I ramble on as the memories come back.  It's called old-age and "decrepitude", as my sister used to say.  Thanks for letting me ramble.

Offline Wicked6

  • New folks
  • Posts: 26
Re: How to build a 2.0l G/BGMR
« Reply #12 on: December 06, 2018, 11:20:45 PM »
Thank you for rambling. You have enlightened me on something I wasn’t aware of, that being that the level of the feet has to be at body level. We were hoping to lower the seat to almost belly pan level, ie, 5” below the body line. The driveshaft, seat interference is something I’ve been looking at and going mmmmmm.
It looks like the Center line of the engine will be about 2” above the bottom of the body, which is also 2” above the bottom of our chassis rails. Our engine is 27” long, and with putting the water tank beside the driver like you describe, we are hoping to put the gas tank in front of the motor. There appears to be sufficient room. We’re thinking 5 gals of fuel should be sufficient for a 3 mile drive at wot.
I find your suggestion of little to no suspension to be interesting, we were going to go without rear suspension originally, but changed our minds after input received.
I was looking at the seating arrangements this afternoon and figured we would be sitting 1/2 into the trunk to get adequate legroom for clutch, brake and go fast pedal.
My ‘18 rule book should be here tomorrow or Monday, so I will have the latest info.
Regards, Pat, aka Wicked 6
I started with nothing, I have most of it left.

Offline Wicked6

  • New folks
  • Posts: 26
Re: How to build a 2.0l G/BGMR
« Reply #13 on: December 06, 2018, 11:56:24 PM »
My 2011 rules don’t seem to have any seat height restrictions in MR. I will be interested in the 2018 rules
I started with nothing, I have most of it left.

Offline bubruins

  • Full Member
  • ***
  • Posts: 106
Re: How to build a 2.0l G/BGMR
« Reply #14 on: December 07, 2018, 12:43:13 AM »
So step 1 for anything G/BG in my opinion is starting with a Nissan RB20det. You're going to run into problems keeping that motor cool at the boost levels you'll need for a record >200mph if that turns into a goal. Cylinder head surface area is your friend. If you're actually just looking for 150mph an ecotec should do the trick. For what it's worth, I've never raced an ecotec or RB in LSR, but if I had the choice... Also may not be wise to use a T56 in anything > 4th gear due to the parasitic loss in overdrive. Most all successful LSR efforts are accomplished with the ideal final drive and a 1:1 trans ratio in final gear.
« Last Edit: December 07, 2018, 12:51:13 AM by bubruins »