Hey guys,

I want to run a 12.50 or better, He is my plan and stock list of items to buy. Please tell me if you think its able to be done!


1991 Pontiac GTA 350 TPI. 700r4 with 3.42s hardtop

Pull stock l98 heads have a Good port and polish job, mill for larger cam and thread in studs

zz409 TPIS cam with a set of 1.5 rollers

miniram intake from TPIS with stock injectors- ( or maybe larger?)

1 3/4" long tube headers with 3 inch collectors into a single 4 inch exhaust with a borla race muffler. ( should I run a single cat?)

PCMforless tune

2500 Stall



good air and a track down hill!

I hope I could put down 350-375 to the wheels with this combo?

please please let me have your thoughts!

 

I honestly dont see it happening. If your going to pull the heads you might as well get a new, larger set. The Miniram intake is a good choice, but the intake will flow more then the L98 heads will, even if there are ported. What about a tb? Going to stick with the stock one? I wouldnt waste money on a 2500 converter, get a 3000 or higher! I'd have a look at some Comp Cams before buying the TPIS one, plus dont go with anything less then a 1.6 rocker. You havent mentioned anything about rebuilding the tranny?? Also your suspension?? Going to need to get every tenth out of the 60' that you can, so attention to your suspension setup and a good slick are a must. And finally.. dont waste your money on a PCMFORLESS tune or any mail order tune!! I had one done for my 383 stroker and it was absolute GARBAGE!!!! Source a dyno and get the car dyno tuned!

 

your heads will slow you down.

 

I was going to run the heads for this summer, Next winter the engine is coming out and a 383 will be going in.

 

If you can have the heads really opened up and 2.02 valve, it will go mid 12's with that setup. A ported set of L98 aluminums will do that and are easier/cheaper to port. Can find them for fairly cheap these days.

Go 3000 stall atleast and make sure its a good quality converter. That setup will run hard.

Wont make 350whp but you dont need that much to run 12.5 anyway. 300whp will get you mid 12's. If the heads are really opened up to flow well, i can see it making 330-340whp

 

how about something like these?

http://cgi.ebay.com/ebaymotors/SBC-C...item3a63c5b83e

 

What's your starting point? - what have you got right now?
and where are you located?

You will definitely need a custom (hands-on) tune for this project.

A miniram intake is going to need much more stall.
You would have to turn some good RPM to get those HP numbers, so you might want to reconsider the use of ported stock heads.
If this is a high-RPM track only project, then check around some machine shops that build for dirt track. They often have a set of used up race heads for sale pretty cheap that could work well for this sort of track project.
If what you're looking for is a good street car that runs 12.5 E.T., then you should probably reconsider your intake choice.

 

Good questions,

I live in Illinois

I talked to the guy at tpis and he said a 2200-2500 stall would be good. But now Im not sure.

The car will spend 95% on the street. We go to the track 2-3 times a summer. I want a good strong street car!

How about a a super ram..

I could grab that super ram in the forsale section and those heads off ebay.

 

Since it needs to be a good street car and you're going to be swapping engines next year, then why not save a lot of trouble and just put a bottle on it for now?

 

ha,

I want all engine power...

Not a big nos fan

 

Hard to tell from those pics but those valves look a little far apart to be 202s.
Who did the porting? Most of whats floating around out there termed "ported" is scary. Ask more questions...who did it, some close ups, any #s for reference.
Dont expect huge ones though L98s just dont get it like that but good enough for 12s. A superram would be a good move imo.

BUT when you do your stroker you may want that mini..see?

 

if you plan to go stroker, get the miniram. Miniram works well on stock L98's tho so I wouldnt be concerned. LT1 is basically a miniramed L98 but the L98 is not quite as powerful. Your just a mild set of heads and mild cam away tho

 

Any other intake options you guys would recomend? or is mini the way to go.

 

I've though about this and here's my idea.

Build it from the back forward.

1. Sticky tires.245/50/16 ET Street drag radials on stock rims will do.
2. Good driveshaft, spohn makes a good, strong, well balanced shaft.
3. Shift kit, trans go makes a stage 2, works good, good trans fluid also.
4. Torque converter. 3000-3200 stall minimum. Circle D makes a well built $400 piece.
5. Trans cooler

I wouldn't dump money into the engine yet. If you do a 383, you will want it done right. Don't Nickel and dime a bunch of cheap parts together. Save your money and look at crate engines when the time comes. You can buy complete setups from $3500 on up that will get you in the deep 12's.

The miniram will do just fine but work on getting the TPI running good for now. Do the free mods, good ignition parts, rocker arms, headers, fuel pressure regulator, etc. It should run pretty good with tires/converter. It will probably outrun MOST cars to the 60ft. Haha I definitely wouldn't do heads/cam or anything internal yet.

 

All depends on what you want to do with it. Cheaper options include single plane EFI, stealth ram, proflo xt, or used and ported superram.

Superram has longer runners, abit more of a PITA to install but does make good power and can support good power with a port job to the base. Its likely to be expensive still compared to the others new. It would be my last choice in the above list simply because I'd build the stroker to peak in the lower mid 6000 rpm range and superram will have a hard time supporting that.

Any of those intakes will work well on a stock L98. I had a buddy run the miniram on a stock L98 with supporting exhaust mods/tune and it ran heck of a lot faster than stock TPI did. I ran stealth ram on a stock L98 with supporting bolt ons and it ran alot faster than stock TPI. On a mild engine, any intake will make substantial gains over stock TPI, even full aftermarket TPI. Once you start getting into larger heads/cam setups or stroker inches, even aftermarket TPI becomes a choke point above 4500-5000 rpms unless you really port the base and siamese the runners to get the short runner effect that the other intakes have.

With your goals for the future, I'd use a short runner intake now. A mild cam swap on the stock ported heads will get you mid 12's with the right converter. Miniram i'd try 3000-3200 stall with a cam that peaks closer to 5500 rpm, shift by 5800-6000. You can throw a big cam in the car as well just for fun if you dont mind trying to tune a rough car and only will run it for a year or so I'd do what the LT1 guys do, cam only CC306 grind

 

http://cgi.ebay.com/ebaymotors/Weian...item2eb39895c0

Is a item like this plug and play how the miniram is?

 

Yes that the holley/weiand stealth ram and is very popular among this crowd. Just look at the alternative intake subform on this board. The first page, count how many topics deal with HSR / Stealth Ram / etc

 

Im going to differ with Orr on this just a bit. The Miniram is a high rpm manifold meant to make power up to 7,000. It produces a long flat torque curve and on factory heads will probably cost you overall torque and in turn performance. It will support 600HP, it's meant to be used with a big cam and high flowing heads. In my opinion, it's way too much manifold for your ported L98 heads. Your heads will run out of breath before the miniram even starts to flow well. In your case, you,d be much better off with a ported factory base and runners. Or even a long runner highflow setup using TPIS large tubes and Bigmouth base. Unless of course you're willing to reconsider using those factory heads. Then your options increase considerably.

 

Im going to pick up those heads off ebay, the l98 of the vette with the 2.02s I would rather run the HSR due to cost, and on the street 7k is not the ideal rpm range.

would those be a okay combo?

 

yeah for the rpm range in question, there are other intakes that will likely match the miniram for power and yet produce much more torque so in return, it SHOULD be a faster car overall. Depends tho, you will make more peak torque with TPI stuff but much after peak torque rpm, the power drops off. miniram/hsr will hold onto it alittle longer and make more average under the curve power. Either way I dont think the HSR or miniram will hurt all that much, but if you can find a good ported TPI base and SLP ported/siamesed runners or the Superram, those would be very effective choices that will compliment the ported heads and cam fitting a 6000 rpm range max.

The zz409, thats a 226/226 cam that will want to go to mid 6000 rpm range shift points if the heads/intake are there to support it. If you use that, I really like the HSR intake since its abit longer runner than miniram, so it will make more overall torque.

Ported vette heads would be a good option but all depends on who does the porting and how much the porting is...if it adds up alot, you may be better off buying a set of aftermarket heads!

ESPECIALLY if you are going to go 383 next year and changing the heads anyway. In that case i'd save money and buy heads now for the 383 and just run them on the 350 as is. That cam and new 190-200cc heads that flow somewhat good will go low low 12's possible high 11's in the right air! My buddy's AFR 190 head setup with 280xfi cam ran 7.7 in the 1/8 which should be 12.0-12.2's or so. we are going to the 1/4 mile tomorrow to see what it can do up top end. Its got the HSR intake and AFR 190's are not as good as the newest 195's by AFR or the 195-200's from DART/Brodix/Profiler/etc.

Thats what i'd do. Spend money on heads now with intent on using them down the road.

 

I like the idea,

Is the HSR bolton how the miniram is? IE injectors and so on?

and what size stall would you say? I want to keep it as street friendly as can be

 

YES the HSR is a bolt on but you need HSR rails and then get the fuel fittings and -6an braided line to make your own fuel lines from the body hardlines to the fuel rails. It does bolt on tho and uses all the factory sensors and vacuum ports but the fittings are slightly different size on some ports so you just need new vacuum fittings and hoses. Not expensive to do.

As far as stall goes, IMO i'd try 3000 with that cam...maybe even closer to 3400 if you go with a miniram or HSR. I had 2800 on my stock cammed L98 with HSR and it ran 1.70-1.71 60 foot times with 3.42 gear. Cam and head work will push torque curve up even higher, so you can get away with 3000-3200.

My friends heads/cam L98 runs 3600 and it went 1.60x 60 foot with 3.90 gear but 28" tire. It could use some more tuning I think and suspension work plus a smaller tire for 1/8 mile useage and it should see 1.5x 60's. Thats where my 383 HSR motor was, in the mid 1.5's and it went mid 11's. He's got 280xfi cam, which is big for a stock cubed low compression motor but it runs pretty well for the power we think its making. Its really driveable too tho.

My definition of "streetable" may be alittle different than yours. If you havent driven or been in a stalled car its definately a different experience. I got 3200 on my daily driver and when my motor was stock with bolt ons it was a daily driver with 2800. Definately a learning experience at first but that was when I was 18-19 and never been in a "fast" car before. If your nervous about it, 2500-2800 is fine as long as its lockup. For a 383 down the road, it will need to be reconfigured to 3000's depending on how nasty you get with the motor.

 

Sounds like a plan,

By the way.. Thanks for taking the time and helping me out! You have some great info! again, Thank you!


Now its time to sell some firearms to get my heads.

Will update will a build thread in a few weeks.

 

Never sell your firearms for car parts

One thing I would like to add, you might have a problem fitting the HSR under the hood of the GTA unless you don't care about cutting up the hood brace. I myself decided to go with a mini ram on my car for this very reason, though I would have perfered the HSR, but I'll be going up in cubes once this engine goes so probably be better off in the long run anyways.

Think tuning would be your biggest nightmare, hopefully someone can burn you a chip that will work with your combo. Guess you can always learn to burn one yourself if needed.

 

Yes I did learn about the hood cutting, Im okay with that. As long as I do a good clean cut it doesnt bother me.

And about the firearms, I have WAY to many. I would not miss 5 or 10 of them. I only have two hands! Im going to keep all my ammo, only firearms for sale.

 

Okay. whats the deal with these? why half price?

http://cgi.ebay.com/ebaymotors/350-C...item5197feebf7

 

On a side note:
the super ram will pull to 6300rpm for sure. with out falling off.

just so some guys know..
(it's all about the right parts)

 

I think those are like the procomp ones they are cheap but some people have done good with them. If i werw you i would pm dyno and ask him what you could do and has 12 sec tpi car.