What should i add to my non turbo combo?
You should up-date the valve train. The stock valve springs can limit your total boost you can achieve. This sounds funny but think about the extra psi pushing against the back of your intake valve wile at the same time the springs are still trying to control the valve at RPM. I know others say you can do it but i repair heads all day long and its easy to see a combo that has or had inadequate spring pressure and the damage that can come about. Now for most stock valve springs we have found them to allow around 3lbs of boost safely. At only 3lbs of boost there is not a big power change over your combo with out a turbo. A lot of combos have single high rev springs. This is a move in the correct direction but again this will limit your complete control of your valve train. We have found this limit to be around 5-7lbs of boost safely.Your starting to make power but more of a tease than a treat!
Now with a set of good name brand dual valve springs you can safely see over 15lbs with out the concern of valve float. So add a set of good valve springs and other quality parts like real chromoly retainers, hardened valve keepers, Ivam or Manley stainless steel valves, solid rocker shafts, and a good set of high quality chromoly push rods. We stock all these parts if you need them. The down side to all this is the stock riveted cam may not like the extra seat pressure. So if your building the combo from the ground up, its time to change the cam for a real turbo cam that is specific for your need and use. A
You will want to run as munch boost as possible on pump gas. Most combos will allow up to 10lbs on pump gas and some even higher. Now the difference from 3lbs to 10 is over 50% increase in power.
Now its time to talk about the exhaust valve guides that sticks out in the exhaust ports. Some makes of valve guides can burn and flake-off real easy. This would not be a problem on a standard carb combo but on a turbo it can be the death of your turbo. Your turbo will not want to become a chipper shredder and eat the guide bits as they try to pass the exhaust wheel wile it is spining over 50,000RPMs! Most of the time this is only a problem on high boost, high exhaust heat combos (over 15lbs atleast) so do not freak out and take a chisel to your guides!
Now lets talk about saving money!!
You will notice that most of thees combos below have small valve heads and low compression but make big power. The size of the valve will not come in to play unless you plan to set the world on fire and brake records down the track. I have a 300hp 1915cc combo that i use in the PRA Super Comp 10.90 sec ¼ mile class. This car runs 6.50's in the 1/8 mile all day at over 107mph and its all being forced thou a 40mm intake at a low 14lbs of boost. I'm a head guy and build some of the most powerful VW heads on earth and i still only use a 40mm intake valve on my personal combo.. Why you ask? Because i have learned over the years that turbos do not care about volume as much as they care about air speed. Yes its all about the speed of the fill and not slow moving volume through the large opening like on your carb only combos. So this sounds funny but in this case size does not mater.
The compression that your combo is set at is vary important. If it is too high for the intended use than heat can plague you and lead to the death of your combo. If set to high can also limit the total boost on pump gas your combo will get away with. Set too low and you have a pig or slug when off boost and that is no fun. You can see how important the “combo” must be when building the correct combo for you!
Track only combo.
If your building a specific combo for 100% track only use don't be afraid of a little compression. That extra compression can make small combos perform like larger combos for leaving the starting line or getting out of the gate. Grate for helping spool up a overly sized exhaust wheel on your turbo. I have all wise built my track combos to have close to 9.0:1 so i will run lower boost but still have more raw motor to leave the line consistently over and over. Thats what its all about in drag racing is doing it over and over time after time. That way if the car did not leave the line the way you liked you can make a change and correct it as you have base line info to judge off of. This only applys to racing combos as they will run there whole life on race gas and not see the street at all. This does not mean by lowering your compression you will sacrifice power at all. Its just hard some times to build boost at the line over and over exactly the same each time. I would rather be able to just mash the peddle and use the rev-limiter than sit there trying to build boost and have the thing bog off the line!
What did a turbo motor of my size make on the dyno?
This is a quick list of some of the motors that made there way to the dyno. Most of the combos were made to make the most power on pump gas. Some and most of the owners would add some race gas and turn it up!
With good valve train and our old base 1600T turbo kit (32x36 pergresive carb) on pump gas.
110hp and 121tq @11lbs (test was on our junk 1600 motor, motor was a used motor to start, we used it as a turbo for 19,770 miles, We did add dual springs, retainers,keepers,SS valves and 1.25:1 rockers with C/M push rods)
With 1600T Ghia kit (T25 turbo) LBC1 cam,35x32 ported heads,7.4:1 on pump gas.
127hp and 141tq @10lbs. This motor was snappy and sound like a big 2L.
with our LBC1 cam and basic 1600T kit (T25 turbo) stock 35x32 heads 7.5:1 on pump gas.
139hp and 154tq @ 7lbs
with our LBC1 cam and 1600T kit (T3 turbo). Motor was used in our baja 67 bug. This motor started off as a 46mm Kadron motor making 96hp and 107tq at the wheels (no belt and aircleaners off) with a old Babe Erson cam.
With a turbo made 155hp and 165tq @ 8lbs. Motor then made its way too the LowBugget race car for two years and ran best of 11.44 @ 118mph at 22lbs of boost. (it did split a cylinder on its last pass trying to run 24lbs of boost!) but on that pass clicked off a 1.42sec 60' and 6.98@101mph in the 1/8 mile but the sound of the air coming out of the cylinder made me shut it down!
with our base 1600T kit (T25 turbo), LBC2 cam, pocket port 40x35 heads.On pump gas.
167hp and 176tq @8lbs of boost.
with our LBC2 cam, base1600T kit (T3 turbo) with our old and small 32x36 pergresive carb.
176hp and 207tq at the wheels on 15lbs of boost. This motor in a stock 1968 bug ran a best of 13.31 @101mph in 1/4 mile on 165 stock tires @12lbs of boost!
1600T kit with a (T3 turbo) and 40x35 ported heads.
241hp and 252tq @ 15lbs of boost. Car ran 11.79@ 115mph on DOT slicks .Full stock steel 67 bug.
with our Manx kit, (T3/T4 turbo), ported 40x35 heads and the holley 500 carb.
240hp and 252tq @ 13lbs of boost. This motor was built to make power, I hope to get info of what this car runs in the 1/4 mile and on the street soon!
My 1915cc combo. (9-9-09)
DPR69mm Wedgmated to a stock flywheel, LowBugget 5.4" H-beam rods, Super case with 10mm Bugpack Racing head studs, 40x37 Pocket Port heads with K800 springs and +.200" valves, LBC 4 cam with LowBugget 1.25 rocker, Mahle piston and cylinders, -20grams wrist pins, 1qt sump with bypass oil control, 2000TS turbo kit with TB73 turbo, Pro Race Wastegate, Turbo prep 500Carb 298hp and runs low 10's all day!!!!
Go for a ride video 1, video 2
with our 2000TS kit (T3 turbo) and a holley 500 carb. LBC3 cam, 40x35 pocket port heads, 7.8:1
198hp and 236tq at the wheels on pump gas. I can run up to 12lbs on pump gas but we leave the boost at 8lbs just in case we get a bad batch of gas.This motor has over 48,000 miles on it now! Car runs a best of 8.55 in the 1/8 mile on 205/65 tires on pump gas.
Would you like to go for a ride in this car? In car video, out for test drive!
with our 1600T kit and (T3 Super 60 turbo) holley 500 carb. 40x35 pocket port heads. LBC3 cam.
No Dyno info. Track 12.20 at 109mph on 18lbs boost with DOT Street Tires.
with our 2000TS kit. (T3/T4 turbo) 40x35 ported heads 7.8:1our LBC3 cam
246hp and 267tq @20 lbs of boost @ 4,900rpms. On 12lbs of boost this monster made 174hp and 240tq. @ 3,800 rpm's. This thing would drive like a dream! Over 200 foot ponds of tourqe at less than 4,000rpms !!!! We stoped the dyno pull as all we wanted was to make more than 225hp. once we did that there was no reason to keep beating on it!
This beast is going in to a 1970 bug for street use only. (the owner says!)
with our 2000TS kit. (GT33 turbo) 42x37 ported heads 8.7:1our LBC4 cam
269hp and 232tq at the wheels! On 14lbs boost. Beast to 7500rpms yet you can drive it on the street!!!
Off Road/Drag Race kit, (T3/T4 turbo) Holley 500 carb LBC4 cam 42x37 ported heads.
256hp and 258tq on 14lbs of boost. All dyno rpm pulls below 6,000 rpms
Street Race kit, (GT33 turbo) Holley 500 carb LBC4 cam 42x37 ported heads. 338hp
with our 2000TS kit. (T3/T4 turbo) 40x35 ported heads 7.8:1our LBC3 cam 321hp and 270tq @20 lbs of boost
with our 2000TS kit. (GT33 turbo) 46x38 ported heads 9.0:1 our LBC4.5 cam 385hp on less than 20lbs boost!!!
More info about our turbo kits
Info about our line of LBC Turbo cams
Info about our pocket port & ported heads