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Thanks for the info. Ya I guess I’m ok with it for now...
For the TC I believe 2500 is ok?
TIA
I wouldnt go higher than 2400 for a street-driven car that I planned to drive around town or dinner or whatever. I think 2000-2200 is about perfect for this particular combo.
When considering Torque Converters there is something called " flash". Flash will be higher than the " Stall Speed", it's instantaneous rpm the converter will allow engine to reach, at launch. Back in the day, I had a calculated need for a 3400 stall converter so I got a 3500. I didn't know about flash at the time. The 3500 converter flashed 4200, too much stall for my application. Just something to be aware of. You also want to keep TCC.
TommyFox, I have a SR on the shelf waiting to instal on my my '87. I have the plenum and manifold and a set of fuel runners. I need to buy a throttle body. What did you use for an air filter system, if that is what you mean by "intake"?
Last edited by YellowEarl; Sep 7, 2021 at 03:27 PM.
Hi Matthew Miller, I like your thoughts on the wide power band. I find it very appealing. I am driving open track days at Waterford Hills in Michigan which is a very technical course (the boss says "you will be passed by a Miata despite your horsepower advantage". With my '87 Corvette L98 engine I can run the whole course in third gear because of the long power curve. It is so different from my air cooled VW back in the day, or my TR7 (wish I still had it.). I am going to instal a SuperRam which I am told has medium length runners. Beyond the 5000 rpm resonance problem in the L98 engine I am told there is a problem with valve float that needs to be addressed. We will see how it goes for rally and autocross as well as cruising the blacktop.
I am interested to hear about making the SuperRam install easier too.
If you are set on the Superram and want to make it easier, the hard part will be the upper intake. Getting the screws threaded in. You can only get maybe a quarter of a turn and the inside ones are a Royal Pain In The ***. So, when I bitched to John Lingenfelter about it being a PITA, he said to slot the bolts so you can get them tight with a small flat blade screwdriver and do the final turn with a wrench.
Gonna give this a bump as I am trying to decide between the FIRST TPI and the Edelbrock PRO-Flo XT. I currently only have the Air Filter mod, a Corsa cat-back, and 4.10 gears on my 1990 6 speed. I just ordered TPIS headers with catless y pipe and a High Flow main cat. My goals for this build is to eventually hit 380 - 400 rwhp while keeping peak RPM @ 6000 RPM or below (aka 5800 to 6k shift point). Future upgrades will include a 383 stoker kit with 6" rods, AFR 195 Eliminators, and a matched cam with 1.6 RR.
The Eddy XT looks to be a good compromise from the mini ram as far as the intake liking high RPM and giving up torque. The FIRST unit looks to give the most usable torque down low, but seems to give out on HP by 5000 RPM which would limit Peak HP and possibly make the AFR enforcers a better buy flowing 250-260 cfm as opposed to the Elims 280-290 CFM. Is anyone aware of a FIRST intake combo making peak power in the 5600-5800 range?
Last edited by TorchLT4; Nov 30, 2021 at 02:12 PM.
Gonna give this a bump as I am trying to decide between the FIRST TPI and the Edelbrock PRO-Flo XT. I currently only have the Air Filter mod, a Corsa cat-back, and 4.10 gears on my 1990 6 speed. I just ordered TPIS headers with catless y pipe and a High Flow main cat. My goals for this build is to eventually hit 380 - 400 rwhp while keeping peak RPM @ 6000 RPM or below (aka 5800 to 6k shift point). Future upgrades will include a 383 stoker kit with 6" rods, AFR 195 Eliminators, and a matched cam with 1.6 RR.
The Eddy XT looks to be a good compromise from the mini ram as far as the intake liking high RPM and giving up torque. The FIRST unit looks to give the most usable torque down low, but seems to give out on HP by 5000 RPM which would limit Peak HP and possibly make the AFR enforcers a better buy flowing 250-260 cfm as opposed to the Elims 280-290 CFM. Is anyone aware of a FIRST intake combo making peak power in the 5600-5800 range?
No TPI-based intake can make good power in the range you want: the runner length guarantees that anti-phase resonance will impeded airflow by 4000-5000rpm (depending on runner cross section). You will hobble any decent heads and cam with that intake. Plus, it won't make "the most usable torque down low" - it will create a bump in torque around 2700-3000rpm, but below that it will be no different than a short-runner intake. This is especially true of the FIRST, whose large runner cross section will mean air velocity at low RPM is lower than a stock TPI. A stock LT1/4 or Miniram might even have more torque off idle!
I don't know much about that Edelbrock intake, but it definitely has the runner length you're looking for. Does it even fit under a C4 hood? Has anyone used one around here and compared it to a Miniram or LT1/4 intake? Is this for your LT4? If so, why not just keep the stock intake and save your money? You could eventually get it ported to the AFRs when you buy them. My 396 LT4 had heads that were very close to AFR 195 Comps and a ported stock intake along with a small but aggressively-ramped cam. I wish I still owned it so you could experience it (you aren't that far from me). It did not lack for midrange grunt or power: it would slightly pull a stock C6 Z06.
No TPI-based intake can make good power in the range you want: the runner length guarantees that anti-phase resonance will impeded airflow by 4000-5000rpm (depending on runner cross section). You will hobble any decent heads and cam with that intake. Plus, it won't make "the most usable torque down low" - it will create a bump in torque around 2700-3000rpm, but below that it will be no different than a short-runner intake. This is especially true of the FIRST, whose large runner cross section will mean air velocity at low RPM is lower than a stock TPI. A stock LT1/4 or Miniram might even have more torque off idle!
I don't know much about that Edelbrock intake, but it definitely has the runner length you're looking for. Does it even fit under a C4 hood? Has anyone used one around here and compared it to a Miniram or LT1/4 intake? Is this for your LT4? If so, why not just keep the stock intake and save your money? You could eventually get it ported to the AFRs when you buy them. My 396 LT4 had heads that were very close to AFR 195 Comps and a ported stock intake along with a small but aggressively-ramped cam. I wish I still owned it so you could experience it (you aren't that far from me). It did not lack for midrange grunt or power: it would slightly pull a stock C6 Z06.
No, I foolishly sold my LT4, this is for my l98. Several people have used the edelbrock XT and all seem to be happy with it. A magazine did a write up on it vs the Super Ram and it gained 22 Hp at the top and lost 13 ft. Lbs. down low on a 383. Personally I just like the look of the black XT over the mini ram.
No, I foolishly sold my LT4, this is for my l98. Several people have used the edelbrock XT and all seem to be happy with it. A magazine did a write up on it vs the Super Ram and it gained 22 Hp at the top and lost 13 ft. Lbs. down low on a 383. Personally I just like the look of the black XT over the mini ram.
Ahhh, okay. I failed to notice your avatar! Okay, that Edelbrock seems like a reasonable bet, and I think it's even cheaper than a Miniram. It may lose some low-end torque compared to a Super Ram, but that may be a different story than a TPI intake. Regardless, I'd suggest that the 22hp extra is worth it. And with all the mods you're eventually going to do, you'll probably want to change the rear gear ratio anyway; so you can just go a step higher and you'll be glad you went this route.
No, I foolishly sold my LT4, this is for my l98. Several people have used the edelbrock XT and all seem to be happy with it. A magazine did a write up on it vs the Super Ram and it gained 22 Hp at the top and lost 13 ft. Lbs. down low on a 383. Personally I just like the look of the black XT over the mini ram.
Get the correct port size Mini -Ram. It's an easier install, similar in performance numbers as the Edelbrock. By the time you buy everything for the Edelbrock you will be at the same price and more headaches...