lt4 hot cam - TPIS intake
lt4 hot cam - TPIS intake
Anyone have any experience with this particular setup. We are currently working through some other problems with the car, but wanted to hear from anyone that has used this setup.
We spoke with the guys at TPIS and they are telling us we should be running about 2400 RPM across the thruway at 60 MPH (that is where the cam starts to work ?) We are currently only running about 1900 across the thruway, 1300 - 1500 normal driving. The motor is real doggish (although we do have other issues we need to work out.)
In addition TPIS recommends running the BLMs in the 115 - 120 range to help the doggishness ?
I'm begining to think we should have ordered a more streetable cam.
Any thoughts ?
We spoke with the guys at TPIS and they are telling us we should be running about 2400 RPM across the thruway at 60 MPH (that is where the cam starts to work ?) We are currently only running about 1900 across the thruway, 1300 - 1500 normal driving. The motor is real doggish (although we do have other issues we need to work out.)
In addition TPIS recommends running the BLMs in the 115 - 120 range to help the doggishness ?
I'm begining to think we should have ordered a more streetable cam.
Any thoughts ?
Joined: Jun 2003
Posts: 5,028
Likes: 78
From: Desert
Car: 1991 Z28 Vert
Engine: 383 single plane efi
Transmission: T-56
Axle/Gears: 8.8 with 3.73s
TPIS is notorious for putting out BS knowledge about what you should and shouldn't do. Sometimes I think there only goal is to get you to buy their products no matter what they have to say.
With that out of the way, I am running a 355 with 9.8:1 CR, LT4 hot cam, Ported and Siamesed TPI setup, headers, T-5, and a set of ported trick flows. I did have a little trouble tuning it at first, but even than I could still drive it on the street fine. I have it tuned better but am still not done.
I have it running in closed loop now with BLMs between 123 and 130. I started to tune it with a rich VE table in open loop. I have it on a 730 ecm running 8D.
The car is streetable, just loud, and very touchy when taking off. I am using TunerproRT V3.1 and V4 in 8D. I can email you the bin file I am running right now as a better starting point for you if you would like.
With that out of the way, I am running a 355 with 9.8:1 CR, LT4 hot cam, Ported and Siamesed TPI setup, headers, T-5, and a set of ported trick flows. I did have a little trouble tuning it at first, but even than I could still drive it on the street fine. I have it tuned better but am still not done.
I have it running in closed loop now with BLMs between 123 and 130. I started to tune it with a rich VE table in open loop. I have it on a 730 ecm running 8D.
The car is streetable, just loud, and very touchy when taking off. I am using TunerproRT V3.1 and V4 in 8D. I can email you the bin file I am running right now as a better starting point for you if you would like.
Member
iTrader: (1)
Joined: Jan 2004
Posts: 319
Likes: 0
From: Ventura, Ca
Car: 69 Camaro
Engine: LS1 converted to LS6
Transmission: 4L70
Axle/Gears: 12bolt 3:42
Do a search on O2 constants. I believe there is a pretty good discussion from Traxion about him tuning the Hot Cam and he does mention TPIS. He does say that it is a great cam but you should be looking for a higher stall converter.....
Looking for more info ...
69Ghost, I tried searching on "O2 constants" and didn't get very far. Does anyone have a link for TRAXION'S discussion on the LT4 Hot Cam? I wish we could search the forums for 3 character words !
Tibo, what do you mean by "Ported and Siamesed TPI setup". Is that a modified "stock" TPI intake with the larger runners ?
I'll also take you up on that offer of the bin ... I've PM'd you with more info.
Fri, we are planning on re-checking the cam timing to make sure we are not a tooth off, if it all checks out, we may end up swapping the stock cam back just to start eliminating variables.
Tibo, what do you mean by "Ported and Siamesed TPI setup". Is that a modified "stock" TPI intake with the larger runners ?
I'll also take you up on that offer of the bin ... I've PM'd you with more info.
Fri, we are planning on re-checking the cam timing to make sure we are not a tooth off, if it all checks out, we may end up swapping the stock cam back just to start eliminating variables.
Member
iTrader: (1)
Joined: Jan 2004
Posts: 319
Likes: 0
From: Ventura, Ca
Car: 69 Camaro
Engine: LS1 converted to LS6
Transmission: 4L70
Axle/Gears: 12bolt 3:42
Read the original post again. The key to the performance of an engine equipped with the MiniRam is BALANCE. Bolting a MR onto an engine that is out of balance with it will lead to trouble and crappy performance. So, long story short, don't bolt a MR onto a stock L98. Comparing the L98 to the LT1 is ludicrous. The LT1 has significantly better heads capable of much more airflow at higher rpms, better valvesprings to handle the higher rpms, and a slightly better camshaft. That engine wants to rev. The L98 doesn't.
Keith...
What is your trap speed in the 1/4?
What torque converter are you running?
3.08 gears!?
What type of 'ported heads'?
What tuning (what PROM)?
The "HOT" cam isn't too big. TPIS doesn't know what the heck they are talking about. They are just trying to sell you on one of their cams. This cam works great. In fact, it is probably the SMALLEST cam that I would recommend with the MR. The reason that your car isn't performing doesn't have anything to do with your cam or your intake. However, it probably has everything to do with the other equipment that you are running.
I hate to say this, but your engine appears to be a prime example of where the rumors surrounding the performance of the MR get started. I would recommend at LEAST 3.23 gears with at LEAST a 2800 stall converter. Anything less will leave you wanting more torque. Personally, I would go with 3.73's and a 2800 or 3000 stall converter. I am running 3.73s with a 2800 and this combo is as tame as can be on the street. I would recommend a good set of heads with the proper springs. Ported stock heads or ZZ heads won't cut it (unless LPE ports those ZZ heads ). You will also need the correct PROM tuning to get the fuel curve on the money. Again ... balance Grasshopper ... balance.
Tim
Keith...
What is your trap speed in the 1/4?
What torque converter are you running?
3.08 gears!?
What type of 'ported heads'?
What tuning (what PROM)?
The "HOT" cam isn't too big. TPIS doesn't know what the heck they are talking about. They are just trying to sell you on one of their cams. This cam works great. In fact, it is probably the SMALLEST cam that I would recommend with the MR. The reason that your car isn't performing doesn't have anything to do with your cam or your intake. However, it probably has everything to do with the other equipment that you are running.
I hate to say this, but your engine appears to be a prime example of where the rumors surrounding the performance of the MR get started. I would recommend at LEAST 3.23 gears with at LEAST a 2800 stall converter. Anything less will leave you wanting more torque. Personally, I would go with 3.73's and a 2800 or 3000 stall converter. I am running 3.73s with a 2800 and this combo is as tame as can be on the street. I would recommend a good set of heads with the proper springs. Ported stock heads or ZZ heads won't cut it (unless LPE ports those ZZ heads ). You will also need the correct PROM tuning to get the fuel curve on the money. Again ... balance Grasshopper ... balance.
Tim
https://www.thirdgen.org/forums/afte...hlight=hot+cam
Trending Topics
Thanks for the reply's
As an FYI we pulled the lt4 hot cam out and replaced it with the stock cam (we had to prove to ourselves that the problem wasn't the cam ... and we did ! ). We are running 3.73 gears however this is a pro streeted car so we have huge tires on the back ( I believe 30" or 31" tall and 13" wide ... somewhere in that vicinity ) The motor was still doggish, pretty much from idle to 3500 - 4000 where the intake really started to show it's potential at this point.
I think there may be some truth to this 2800-3200 stall converter discussion.
We are using the stock converter. But why was the stock TPI setup so pwerful down low ? We were able to smoke the tires right off this car with the stock setup.
I think there may be some truth to this 2800-3200 stall converter discussion.
We are using the stock converter. But why was the stock TPI setup so pwerful down low ? We were able to smoke the tires right off this car with the stock setup.
Member
iTrader: (1)
Joined: Jan 2004
Posts: 319
Likes: 0
From: Ventura, Ca
Car: 69 Camaro
Engine: LS1 converted to LS6
Transmission: 4L70
Axle/Gears: 12bolt 3:42
Short runners and big plenum. I have a LT1 intake and supposedly it was modeled after the TPIS intake. There are still major differences and one is the 3.5" runner length as opposed to a 4". Sounds small but it is still 12% shorter than a LT1 intake. I also think that when you combine that with a larger plenum you get a high rpm motor that needs some velocity to wake it up. The LT4 hot cam was designed for a LT1 type intake no doubt and they work well in LT1 car with little mods. I would continue looking at some of Traxions comments on the subject he had his car running arount 112mph in the quarters and also did some testing differences on the intakes. The info is there...
Thanks
As you can tell ... we are very new to this tuning. This is the first car I have attempted any type of tuning on. I will keep reading and trying to absorb/make sense of all this.
Joined: Jul 1999
Posts: 10,950
Likes: 27
From: Orange, SoCal
Car: 1990 Pontiac Trans Am
Engine: 355 TPI siamesed runners
Transmission: Tremec T56
Axle/Gears: 12-Bolt 3.73
The LT4 hot cam is streetable but it required me to make numerous fuel changes at idle to get it to work with the TPI computer. We really had to lean it out. After that, its been great.
The Miniram really likes higher RPMs, so getting a higher stall converter should really help. Changing to 28" tires should help too. With 31" tires I would think you need 4.10 gears or higher.
The Miniram really likes higher RPMs, so getting a higher stall converter should really help. Changing to 28" tires should help too. With 31" tires I would think you need 4.10 gears or higher.
Junior Member
Joined: Jun 2006
Posts: 38
Likes: 0
From: France
Car: 1990 Iroc-z and 1989 Iroc-z Conv.
Engine: 350 TPI Vortec 472RWHP
Transmission: Tremec TKO
Axle/Gears: 7.625/3.73
your bin interrest me too. I run a 350 with aluminum vortech heads a LUN 54743 camshaft (.471/.480 & 219/227 @.050 LBA112)
would you eventually share it with me?
thanks.
would you eventually share it with me?
thanks.
Joined: Jun 2003
Posts: 5,028
Likes: 78
From: Desert
Car: 1991 Z28 Vert
Engine: 383 single plane efi
Transmission: T-56
Axle/Gears: 8.8 with 3.73s
Thread
Thread Starter
Forum
Replies
Last Post
1992rs/ss
NW Indiana and South Chicago Suburb
14
Jan 31, 2025 05:10 PM
1988iroc350tpi
Tech / General Engine
8
Aug 14, 2015 07:52 PM
Sanjay
Engine/Drivetrain/Suspension Parts for Sale
1
Aug 12, 2015 03:41 PM
