Turbo & cam choice for 3.8 Stage 1

Nashty

WORLD'S FASTEST ......geo
Joined
May 29, 2001
Motor is a 3.8 with a 3.4 steel crank, 2 bolt mains, 8 bolt head pattern. Ported Champions w/ scorpion rockers. Going to use a solid roller so it can rev and use a FAST (or maybe that new Big Time ECU).

Car will weigh around 2200 with me in it. Has a powerglide, strange strut front end, 4 link in the rear.

I'd like around 800hp. I originally ordered a TSM 71.5 GTQ for it but Harry recommended a GTQ 70 (which I ordered) it has the ported shroud. Will be a 4 bolt tangential housing w/ 3.5" DP. Does that seem reasonable to you? I can go up to a 72 in that housing. Harry thought I could go with a tighter convertor with the increased spool this turbo will offer.

The cam. I see all these giant cams you good folks are recommending and Strezo recommended no bigger than a 216º for this motor and my HP goal. Again, this is a solid roller. Does this sound right?

My old GN had a hydraulic 210º billet roller in it and I went 131 with that on 25psi with a 70 (p trim) turbo. This car will have a liquid IC and I'm seriously thinking of a small hit of nitrous to kick it out of the hole. I'd rather get my speed on the short end of the track than try to run it out the back end due to my short wheelbase (90").

I'd really appreciate your thoughts...

Roger
 
For 800hp you don't need a big cam (or a solid roller for that matter, but I can see why you'd want one)..... If Strezo recommended no bigger than a 216* for your motor I'd listen to him (he didn't do you wrong last time, did he?):D That guy knows his stuff (just ask Mr. Bamford):cool:
 
Also, you said you'd rather get your speed on the short end of the track which IMO would favor a smaller cam instead of a big one:)
 
Originally posted by 86brick
...If Strezo recommended no bigger than a 216* for your motor I'd listen to him (he didn't do you wrong last time, did he?

I really liked that cam but I always felt there was some left on the table by going that small. Before I called him, I was thinking of a 218º cam. My motor is smaller than the stroked TSM motors so I know I don't need anything as big as that, but still, 800HP is alot of power. (It's so easy to be jaded to these big numbers :D )

One things for sure, this motor will be a docile one. I may just have to add the gear drive sitting on my shelf to make it sound more like a race car. ;) Wouldn't want anyone to think that a Geo Metro was slow.

EDIT:

BTW, I'm going solid cam because I plan to rev this thing to 6800 regularly when racing. That's going to cause some pucker first few times I do that. Years of trying to keep it down in the old 109 block have got me scairt of anything north of 6K.
 
Originally posted by Nashty
I really liked that cam but I always felt there was some left on the table by going that small. Before I called him, I was thinking of a 218º cam. My motor is smaller than the stroked TSM motors so I know I don't need anything as big as that, but still, 800HP is alot of power. (It's so easy to be jaded to these big numbers :D )

One things for sure, this motor will be a docile one. I may just have to add the gear drive sitting on my shelf to make it sound more like a race car. ;) Wouldn't want anyone to think that a Geo Metro was slow.

EDIT:

BTW, I'm going solid cam because I plan to rev this thing to 6800 regularly when racing. That's going to cause some pucker first few times I do that. Years of trying to keep it down in the old 109 block have got me scairt of anything north of 6K.

218* sounds like a good size cam to me.... That aint far off from what Dan told you and since the motor is smaller than your 109 you don't really need to go with a big cam as you said..... When I said you don't need a solid roller but I can see why you'd want one I was thinking you'd want to rev it past 6K on a regular basis so going with a solid is a good idea.... Nothing wrong with a docile motor or people thinking a Geo Metro is slow (you can ask some of those BB Chevy Boys if they would like to race a slow little Geo for some money):D
 
Rodger,

Do you really think you will need the NOS to get the car going?
With your power to weight ratio you should be able to sneek up on 167-170mph. How big and tall of a tire are you going to run?
That will let up know how to gear the car and where the power band will need to be to get the MPH you want.
 
Im going with a 224 duration cam, W/ a GT80R Innovative Turbo
On my stage 1 3.8
Otto
 
Originally posted by KLHAMMETT
Im going with a 224 duration cam, W/ a GT80R Innovative Turbo
On my stage 1 3.8
Otto

Mind if I ask who recommended that or are you going independently? I think the 216-218 is probably where I'm going to end up. As I said before, I don't have a big motor and the car will be pretty docile. It should be a pretty nice street car with the milder cam and should idle pretty even. I don't mind the choppy idle but it tends to hurt the car off in the bottom end with too big a cam.

John - the nitrous is my ace in the hole if I need it to attain my goals. I'm not afraid of it (even though I've never used it). Todd King schooled me on it pretty well. The motor is going to be relatively tame so the nitrous won't jepordize the integrity of it all. Besides, imagine coming off the transbrake with about 12# of boost @ 3500 rpm and a 100 shot on top of that!! KATY BAR THE DOOR !!!
 
If you are using a stock or S1 block, you might want to reconsider using a solid roller. The lifter oiling is drilled right through the lifter bores. At max lift you could uncover the oil holes with the solid roller lifter and cause a hemorage and loss of oil pressure.

You could bush the lifter bores to avoid the problem, or use a hydraulic roller cam. The hydraulic roller lifters keep this area covered up.

If you use a mild solid roller (lower lift) you might never see the problem.

Dave
 
Originally posted by Nashty
Mind if I ask who recommended that or are you going independently? I think the 216-218 is probably where I'm going to end up. As I said before, I don't have a big motor and the car will be pretty docile. It should be a pretty nice street car with the milder cam and should idle pretty even. I don't mind the choppy idle but it tends to hurt the car off in the bottom end with too big a cam.

John - the nitrous is my ace in the hole if I need it to attain my goals. I'm not afraid of it (even though I've never used it). Todd King schooled me on it pretty well. The motor is going to be relatively tame so the nitrous won't jepordize the integrity of it all. Besides, imagine coming off the transbrake with about 12# of boost @ 3500 rpm and a 100 shot on top of that!! KATY BAR THE DOOR !!!

Spec came right from Ken Duttweiler for this cam
 
If Strezo recommended no bigger than a 216* for your motor I'd listen to him (he didn't do you wrong last time, did he?) That guy knows his stuff ...........

I hope so, he is the guy building the motor for The Riviera.;)

Roger, is it a secret what type of car (Geo Metro) this is. The Opel had a 94" wheelbase but is now at 100.5". At 2,200#,you are 500# lighter. I agree with John W. that you will be approaching 165-170 MPH. I don't think you will need the nitrous to get you going. Are you going to be able to run a big tire? The glide has several 1st gear ratios to help with the short times. How much info were you able to get on the "Big Time" unit?
 
Originally posted by turbodave231
If you are using a stock or S1 block, you might want to reconsider using a solid roller. The lifter oiling is drilled right through the lifter bores. At max lift you could uncover the oil holes with the solid roller lifter and cause a hemorage and loss of oil pressure.

You could bush the lifter bores to avoid the problem, or use a hydraulic roller cam. The hydraulic roller lifters keep this area covered up.

If you use a mild solid roller (lower lift) you might never see the problem.

Dave

I have a set of solid roller i am checking now, THere used to be a set made that did not cause this problem in the s1-109 blocks, But if not i am going to convert a set a hydraulic roller into solid rollers. I got these on an ebay deal and now i am finding out that i should have did a little more research before i bought. Cause now i am stuck for the whole thing.
Otto
 
Crane makes a set that is drop in.
I think Lonnie Diers posted about them about
a week ago!
 
Originally posted by opeltwinturbo
I hope so, he is the guy building the motor for The Riviera.;)

Roger, is it a secret what type of car (Geo Metro) this is. The Opel had a 94" wheelbase but is now at 100.5". At 2,200#,you are 500# lighter. I agree with John W. that you will be approaching 165-170 MPH. I don't think you will need the nitrous to get you going. Are you going to be able to run a big tire? The glide has several 1st gear ratios to help with the short times. How much info were you able to get on the "Big Time" unit?

Sorry if I came across secretive about the car, not trying to be. Yes, it's a Geo Metro tube chassis car. The rear tires are 28 X 11.5's. I think that's enough baloney for no more power than I'm making. I wanted to keep the rear track narrower than the front and not have tubs half way up the rear windows. For now, I'm going to use a stock 1.76 carrier in the tranny. I've thought about the 1.96 but I thought nitrous may negate that need (if it's even necessary).

Anymore on this solid lifter issue? First I heard of it, I'm a 109 guy taking a baby step into the stage world. Ruggles built the motor I'm using. I was just going to change the cam in it.
 
solid lifters

Rog the part # for the crane solid rollers for a 109 or stage 1 bolck is
62518-12 $322.99 through jegs 8 to 10 days. I was quoted $260.00 from a local engine builder.
 
can you run those solid lifters with any roller cam ?

Or does it have to be billet or??????????
 
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