OK. I've searched and searched a bunch more when I was thinking about buying a SuperRam, but haven't found solid answers. I have a bolt-on (CAI, headers/exhaust-220rwhp) 1991 L98 Formula that is a nice-weather daily-driver. I would like to improve the intake without changing the character of the driving experience. Soooo. What are the real gains with a LTR set-up? 20rwhp/rwtq? More? Less? Any quantifiers like 1/4 mile times, or real-world driving experience would be great.

They don't make the Superam anymore. You have a 91 Speed Density car and they respond very well to the Holley/Wieand Stealthram intake but it's tight fit with the Firebird hoods. However the are worth a solid 40 to 50 hp on a speed density car.

Other option would be a TPIS miniram if you did not want to deal with the hood clearance issues. Also a solid 40 hp. But a little pricey. That's all you have left to pick from unless you want a High flow base and runners but they are only worth maybe 15 hp.

Thanks for the reply! I wish the Super Rod "TPI Shootout" article was on a more stock engine...

A stock L98 would be great with a Miniram. Why are you not considering it? It's a solid 40 hp to 50 hp gain on a stock motor. Actually closer to 50 hp. The only characteristic of the car that is going to change is that it will be faster. However, the cost is a big reason to not consider it.

http://www.tpis.com/index.php?module...niRam+Manifold

The mini ram will kill every other intake setup. I have used the LT1 intake and the LTR/Big mouth base and the miniram and can say that the miniram has the best mid to high end power and the bigmouth base setup is the one with the most torque. Mini ram if you have the money. If not, wait till you have the money, then get the mini ram.

YOU HAVE NO OTHER GOOD OPTIONS!

Now I will get flamed but I don't care. So many people are going LSX now that the old school sbc guys like me get flamed all the time regardless.

But to get full advantage of the MR potential you need a new cam,

For comparision purposes ;if you consider their base engne with stock TPI made 150Hp more than a stock TPI engine (400Hp) then taking 150Hp off all the reported figures gives you a ballpark comparison on a stock engine.

What you are interested in is not the pure Hp output but the characterictics of each intake.
Note all the TPI (LTR) setups flatline over 5K whereas the HSR and MR pull through 6K.

Yes, it is a great upgrade with a new cam but even on a stock motor it's an awesome upgrade.

Could not be better said. all4u I am still a SBC guy. You have my full support. No flaming here.

Thanks for the reply!

I have not considered the MiniRam because I already have a fast, screaming-high-end, cammed Z06.
With the Formula's L98/700R4 combo, I like the early torque for driving around on the street where the car will spend 99% of its time. From everything I've read including the stickies, the MiniRam drops a lot of that early torque for the huge upper-end hit. If I am way off-base with this, please correct me.

Thanks for the input! I'm crossing my fingers that maybe you have dyno or track numbers comparing the stock TPI with the BigMouth/LTRs. That would be awesome...especially on a fairly mild engine.

I guess I could perform a gradient percentage, but wouldn't underlying factors like valve-events, head-port flow and dynamic compression kind of skew the numbers? I'll use it as a ball-park, though...thanks for the idea!

Most exhaust only L98s are doing bottom 14's with stock TPI/stock converter/3.23-3.42 gears

From my experience... 13.6's with 2800 stall,slicks/3.42 gear/ STOCK TPI, full exhaust in good air. 1.7x 60 foot, 13.63 at 97mph i believe it was.

stealth ram swap with ok but lean tune with same mods... similar air conditions went 13.2's at 101, 1.7x 60 foot as well. Few more bolt ons like rockers/underdrive pullies/drag wheels, I went 12.9's at 104
I dyno'd 254/315 hp/tq with that above setup that went 12.9's. Very lean tune. Stock TPI with exhaust is high 220's/low 230's hp.

My buddy's 88 L98 would run low 14's as well stock L98 with TPI all stock. He put in 3.73 gear, BIG TUBE base and runners, new throttle body, and tune and was doing 13.6s in the heat at 99 mph. Stock tranny/stock converter on street tires. 1.9x 60 foot. So thats over half second reduction in 1/4 mile times. I raced him countless times side to side with my stock TPI/2800 stall car and I'd murder out the hole, but he's catching by 1000 foot and passes me at the stripe. I was doing alot of 13.8's in the heat to his 13.6's

Good track gains can be had with intake swap on stock motor. Doesnt matter which one you use, TPI or Miniram/stealthram, as long as it flows more than stock you will pick up good gains on exhaust modded L98.

Once you go heads/cam, then it really does matter what intake you use. shorter runners will make more hp.

Yep, I still have a stock 'vertor and 3.23s out back. If I did do heads and cam, it wouldn't be anytime soon unless the current engine puked. Even then, it would be a mild set-up. After looking at the SuperRod graphs again, I liked the look of the BigMouth/LTRs because my Formula would mainly be a driver.

Thanks for everybody's input and please keep it coming.

TPI torque on the street is FUN. I have a stock LS1 trans am and its not quite as fun as the TPI torque even tho the LS1 is abit quicker than my old TPI car.

For a daily driver bolt on car, its hard to beat aftermarket TPI stuff. I'd look into the FIRST intake, as it looks promising and its price is hard to beat.

If BBK ever releases the turtle ram, it also will be a nice choice for both higher rpm power and torque as its like the superam, has midrange runner length.


Either way you go it will work well. Best bang for buck mod however is still going to be 2500-2800 stall converter. That really is fun.

I also have all stock 91 Formula. I plan to see how well it will run with only drivetrain mods at this time.

Orr89RocZ, what do you recommend for stall 2600 or 2800, I'll be getting the PI vigilante 9.5 single??

My suspension list will be, Alum DL, J&M new poly ball LCA, bolt on relocation, panhard bar, and nittos drag radials.

Like danziger I really enjoy the quickness of TPI cars, the tq allows for some very quick 0-30 and 0-60 times. My only problem is mass spin in second, Im hoping the above mods help plant the tq...

Yah. The TPI is a blast for a street car, even if it is slow by today's standards. I had a 650ish rwhp LS1-based 382/150shot combo in a 2000 Z28 and currently have a cammed 421rwhp Z06, so I appreciate the LSx as well.

I'm thinking of getting a Edelbrock base, ASM runners and cleaning up the plenum and would be happy with 25rwhp/25rwtq across most of the curve.

The FIRST is sweet, but so few people have one that I am a little leery of buying one.

I will go with a mild convertor at some point, but for now I'm pretty happy with stock.

Thanks for the replies!

You don't see too many nice 3rdGen Formulas anymore, so congrats! Here's a pic of mine:


I enjoy the neck-snapping immediate feel of the TPI, even if it isn't ultimately fast...

my tpi is a very fun street car... i think i have too much torque because i have traction issues of the line even with all the suspension upgrades i have done.... from 0 to 70 it feels unbeatable.. all your power is made down low so tpi makes for a perfect street car....

dittos, here is mine

SLP gta, just so you know, I'm jealous, really freakin' jealous. WOW!

(where is that smilie that is clapping his hands or is that on another forum I'm thinking of?)

Pretty! Nice color!

bolt on TPI car that loves to see some track time, i'd go 2800 stall. Thats what I had and it was perfect for the 4800-5000 rpm shift point. 3.23-3.42's work well with 26" tires

2800 is plenty streetable. I had 3600 in my 383 last year and it was mild on the street, i should have gone abit more if i stayed n/a but i added a 150 shot which made it more like 3800-4000 stall speed

tpi's are really neat looking and are VERY fun to drive..and i'll admit it does take alot of work to make them really fast and shine.... i dont know if its tpi or just owning a gta its probably both but i love driving my car.... i can really care less if there are people faster than me... i think the reason i love driving it so much is because i basically do all the work and put it in the car myself... i remember when my car felt like poo, was slow and kept having issues and breaking down every other week... now ive basically went through everything and it seriously drives and handles like a brand new car now... i have people giving me thumbs up and saying nice sounding car and saying wow now thats a classic.... i knew nothing about cars until i got my gta..nothing feels better than driving something you've built and spent your hard earn money on and it even feels better when you do mods that make the car handle better and overall better than stock... i treat my car like a child lol.... i buy better parts for it whenever i have the cash and give it more attention than i do my friends lol... i have one awesome tpi...

Thanks for all the replies! I may even leave the factory TPI on there until I do any major engine-work. After looking at all the options, I am pretty sure I am keeping some form of LTR. I am entertaining the FIRST intake as well...