Yarnboy

I'm interested to know everyone's impression of the old Hot Rod article that everyone reverts to when the famous "How fast can I make my 305" thread is posted. This motor only lasted on the dyno..What are some of the problems people see with this build? I mean making 400hp at 7k seems a bit radical..Does anyone know what blew on the motor? Did it throw a rod? I'd really be interested in trying to build a TPI 305 that was a low comp. motor (8:1-8.5:1) that could put down 330 -350hp at the wheels. I want to build the motor for a 14lbs kit (d1sc) on pump gas. I'm just wondering if this is a fruitless effort, or something worth persuing. Any input is greatly appreciated..

Willie

iTrader: (1)

Fruitless? All I have to do is look in my garage to see one. And it's been there with the D1SC for three years. The only difference between your plan and my car is I do not put down 330-350hp at the wheels. I'm more like 450-475hp.

Yarnboy

I'm very familiar with your car, it's completely awesome..I was talking about 350hp at the wheels..NA..On a 14lbs kit I'd like to see 600hp at the wheels. Didn't mean to stir up confusion..

Willie

iTrader: (1)

350 N/A rwhp would be possible, but at the expense of driveability. I know 300 N/A rwhp is very realistic. To get 600 rwhp out of a 305, you will need more than 14-psig boost.

Willie

Yarnboy

Driveability as far as MPG or just impractical all around? I have a 4 banger that serves as the daily, so mild in-driveability is acceptable. But I do want it be a street car, so I'm shooting for no more than 17lbs on the street (to run on 93), and if I understand correctly, that's about the magic number for d1sc to get 100% gains. I think the highest comp I could run in that trim would be no more than 8.5:1 with your IC setup..

Willie

iTrader: (1)

Here's the dilemma. You must design an engine either to run NA or with a supercharger. Albeit, a centrifugal is very efficient on the top end and you can literally design an engine as though it will be NA and still run the centrifugal, there's always a compromise. So if you design an engine around a centrifugal, it will not run its best NA. The opposite is true too. Here's but one example of this:

You know C.R must be held relatively low to run a blower. How would this car with ~8.5 to 1 run without a blower? Not as good as if its compression were higher. So to be able to attain 350rwhp NA AND 600rwhp with a blower would be very difficult on a 305. Also, an engine with low compression and a blower with high boost will make more power than an engine with high compression and low boost.

I know 300rwhp is attainable while retaining driveability. In that, I mean with full accessories (including smog pump), fully emissions legal, with acceptable gas mileage and very little loss in low to mid-range torque. I feel 350rwhp is pushing this envelope. It would necessitate a much larger cam (to which a 305 has it's physical limits), higher stall converter, etc. Do you know what it's like to drive a 4500 rpm stall converter daily? It's not a pretty sight.

Bottom line: You want 600rwhp? Design an engine around a blower producing massive amounts of boost. Don't worry about how much this engine will produce NA.

Willie

onebadwagon

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you "could" make 600rw on 16 psi, theoretically, but that would be an airflowin' son of a gun.

330cfm on the intake side all the way through, 250 on the exhaust, and a BIG blower, could see that kind of power at that psi.


adam

Yarnboy

I want to build the motor for 600rwhp on the street..I seem to have the habit of misleading with my posts I don't care about driving the car with out the blower, because I wont. I have the 90hp '90 GS for that. I was only giving the N/A numbers because I guessed these would be the numbers I need, to get 600rwhp on pump gas. I have a T-56 and the smog pump is removed. I will try and get in touch with you over this weekend to get more info/ideas from you. Thanks alot..

mypontiac

You can start the mods with bolt ons from SLP.

http://www.slponline.com/main.asp

You will need to get the car breathing with headers and large exhaust.

Good luck with going N/A.

I listened to the advise of Willie with my 305 and all I got out of it was 343 RWHP.

Oh. But I forgot to mention that this was with the largest pulley.

I am installing the next smaller and running Alky injection to fully eliminate knock.

Best advise here is to do much research on previous posts. There are a lot of things to consider if you are going to push maximum HP. 600 + start looking for forged internals! I will be happy with 450 rwhp and no knock!!!

Do your homework!

Yarnboy

Yea I've got all the bolt on's, and some mild motor work. I'm not going for an N/A car at all, the only reason I said anything about that, was because 340+ was a number I was looking at so that around 14-17lbs, I can make 600+rwhp on pump gas. Forged internals for sure..Where to start where to start..So much to do! (buy)

mypontiac

Here is some additional information to help you with tuning once you get your set up complete.

Go to these vendors for products to help you tune the SC car.

http://www.akmcables.com/dss.htm

I used the Datamaster software and send the files to Alvin at www.PCMFORLESS.com to tune the new chip.

AKM sells both the cable and Datamaster software.

http://www.alamomotorsports.com/fjo_wideband.html

FJO Enterprises sells an excellent A/F Ratio meter. You will need this to tune at WOT.

Good Luck!!!

Yarnboy

Thanks alot man. What's your current setup? I've been gone for awhile..And I don't know where you are now with your car.

mypontiac

This is the best post for a progression of the modifications on my TA. Photos are also posted.

https://www.thirdgen.org/techbb2/sho...postid=1394821

Feel free to ask any specific questions.