Hemco Machine - Turbo Plenum


HIGH 10's on Drag Radials

Turbo Plenum for Buick turbo-V6

GS X-tra
Steven Crisafulli

Here is the current build-up on my gold, '87 Turbo T. I have titled the build-up, "A Recipe for High 10's on Drag Radials."   Last year the car ran a best of 10.94  @124.37 with 30 psi showing on the boost gauge (see the 1996 Nov./Dec. issue of the GS X-tra). My goal for 1997 was to put the car solidly In the high 10's on drag radials with less boost pressure. This meant producing more horsepower. The motor was removed and freshened and the only change made was to move up to a 210/205 camshaft. This addition alone was worth 2-3 mph. Also, a six-point roll cage was added to comply with track safety regulations. In Bowling Green this year, the best pass on the drag radials was an 11.19@124.65 with a 1.75 60' time at 24 psi. The engine was producing more horsepower, but getting it to the pavement was the tricky part. After getting back from Bowling Green, I did some suspension tweaking. Some minor shock adjustments and the addition of a set of Moroso rear trick coils did the job. I headed to the local drag strip several times and was able to click off several 10.90's at 125+ mph with 60' times in the low 1.60's.

Prior to the East Coast GSCA Regional at Cecil Co. Dragway in October meet , I purchased a HEMCO Machine plenum cover. I removed the stock plenum and bolted the new unit on the motor and headed to the track on Friday night for a test-n-tune. The car ran the low 11's on Friday with trap speeds over 127 mph, but the 60' times were way off at 1.84. It appeared that the engine was making more horsepower with the HEMCO Racing plenum cover. The engine was always running leaner with higher EGT's, so additional fuel was added to the fuel map. But, it also became apparent that the 1-2 shift was getting sloppy with the engine revs hitting 5800rpm. The next morning I left the car untouched, heated the drag radials and headed down the track. The launch felt better than the previous night. I was pretty excited when I read my time slip of 10.87 @127.31 mph with a 1.67 60' time with the boost pressure of 26 psi. After this run, I was told to have the car re-inspected. The tech inspector told me I needed a crotch strap on my safety harness. I did not have one, so needless to say, I was not allowed to try and back up the pass.

A couple of weeks later, I headed to my local drag strip to try and better my new low ET. With the engine bouncing off the rev limiter on the 1-2 shift, the car still managed a 10.98 @125.68 mph with a 1.63 60' time at 26 psi. Modifications for next year, include upgrading to a Mark Jackson 20 row intercooler, and replacing the TA-61 with a John Craig TE-45 turbo, upgrading to larger fuel injectors and freshening up the transmission. These upgrades along with some suspension tweaking should put the car in the 10.60-70 range at 130+ mph on the drag radials. If any members have questions, please feel free to contact me.

We really enjoy build-ups like this one for several reasons: First of all, Steven sent us a documented (With time slips) and well-edited, typed copy with all the essential data and facts. Secondly, this provides another "recipe" for club members that obviously works without any hidden secrets. Thirdly, Steven was gracious enough to offer his assistance via phone # to his fellow club members. And last, but certainly not least, this is another Buick that personifies our club motto of: "Going Fast with Class" - and In this case with a real haulin ass ultra-sleeper!

A Recipe for High 10's on Drag Radials

Car: '87 Turbo-T with no fiberglass, no swaybars, and a 6-point roll cage. Weight w/driver: 3,600 lbs

Engine Shortblock: Stock Block 231"; stock crank, rods and main caps; TRW forged pistons w/Total Seal rings; ARP head and main studs.

Heads/Valvetrain: H210-205 cam w/Federal Mogul lifters; factory iron heads w/ radiused intake and exhaust bowls; Manley 1.77" intake and 1.55" exhaust valves; T&D 1.65 roller rockers.

Turbo: John Craig TA-61 w/Garrett stock wastegate actuator.

Intercooler: Mark Jackson 17 row stretch intercooler.

Exhaust: Stock headers; Terry Houston downpipe; ATR 2.5" stainless steel exhaust w/Pitbull mufflers.

Fuel System: 55 lb. injectors; stock fuel lines; dual in-tank fuel pumps. VP C-16 fuel.

Intake System: Stock intake and throttle body; Hemco Machine plenum; 14" K&N air filter.

Ignition: Stock; Quad Air voltage booster and plug wires; Autolite 23 plugs @ .035 gap.

Engine Management: Accel Programmable DFI; programmed by myself with help from White Racing.

Transmission: Stock 200-R4 by Joe Schilling w/Del Trans 2800 stall lockup converter.

Rear End: 8.5" 10-bolt, 3.42 gears on stock posi Unit; Moser stock replacement axles; Koni SPA-1 drag shocks; Global West lower control arms; stock upper control arms w/poly bushings; one air bag on right rear at 25 psi. 

Tires/Wheels: Stock 15"x7" Turbo-T rims with 275/50-15 BF Goodrich Drag Radials in rear and P235/60-15 in front.
Date Place Time (Seconds) Speed (MPH) 60' Time
Nov 1996 75-80 Dragway 10.92 124.70 1.54
May 1997 Beech Bend 11.19 124.65 1.75
July 1997 75-80 Dragway 10.94 123.80 1.60
Oct 1997 Cecil Co. Dragway 10.87 127.31 1.67
Best MPH 127.31
Note: above runs made on BF Goodrich Drag Radials and through full exhaust.