Help me out. I took a rode trip to Colorado from Utah and the fastest my 1997 TA was 110 mph. It seemed like there was governored at that speed. It started sputtering. What's up with that. Is this normal? How do I remove it????????????? It is a stock LT1 with CAI.

LT1's that didn't get the speed rated tires (the 235's weren't Z rated, the 245's were) are limited to 110ish. I think the governor is in the PCM, and thus can be tuned out by any LT1 tuner. 97 is OBDII, so probably easiest to send it off to PCMForLess or someone similar.

I noticed you are fairly new here so.........

Its a free country but.... This is a racing forum so we are not suggesting you should alter your governed speed for the purpose of exceeding the posted limits on public roads in unsupervised non racing applications. Bad idea. Very bad idea.

See how fast your car will go on a race track..... please.

Bock

I appreciate your feedback. Although I may be new to this forum I am not new to the racing arena. I have participated in SCCA for years with a race-prepared Mustang. After years of being beaten by the f-bodies, I decided to purchase one, recently, and commit treason. I had understood the top speed of my TA was 142, not 110. This is a concern of mine since I will be attending PDX/HPDE at MMP, and possibly Pueblo, this spring and intend to participate in Open Road. With a race prepared suspension and brakes, I decided to pass a car on the long and boring trip on the I-70. Yes, I went to 110, which is fairly easy with the 5.7.

My main concern is top speed at the MMP on the straights. I understand that it is possible to exceed 100 mph. My intention is to determine how to prepare my car for this experience on the track and in open-road racing applications. I understand that this is a race forum and I am not looking for ways to alter my top speed to exceed the posted speed limits on public roads in an unsupervised setting. I also know how to tune my vehicles. Unfortunately, the LT1 is a unique engine to me with the optispark and other challenging issues. I would much rather hear from you professionals on how to resolve this issue than to post on a teenage camaro website. They would probably load me full of crap.

Thanks for your advice and will be adjusting through LT1 tuner.

Top speed on an LT1 car in stock-ish trim should be closer to 157 mph (give or take a bit). The L98 3rd gens (350 cars) were also quoted at 157 top speed (and seemed to run about that from what I remember). I think 142 is a bit low, the TBI 305 cars (3rd gens) would get there without much by way of modifications.

I'm far from a professional, believe me.

That should be all you need. I assume that you have the 4th gen 3" aluminum DS? That should be fine assuming that you have sane gears (3.73 or less). Make sure you tires are speed rated appropriately and in good condition, balanced, appropriately inflated etc. I assume the car is in good mechanical shape and brakes capable of whoaing the sled down (good performance pads). Those things should be obvious to you since you have SCCA experience.

I can’t really think of anything else other than have fun and be safe.

Sorry for the simplistic original response...we get all types on here.

I doubt you will be seeing anything close to 142 (or 157) at MMP in stock trim although 100+ is a DEFINITE since you have some experience. The biggest trick at MMP is carrying speed through turn 1 at the end of the straight (which is the entire drag strip). My best top speed at MMP was 135 and that was with 340 hp to the wheels.

As mentioned by others, good tires and brakes are essential. You may wish to look into an LS1 (or C5/C6) brake swap (from a 98+ model Fbody or Corvette) since the LT1 brakes are a well known deficiency in our cars when running at high speeds. You can try the LT1 brakes out but you will be very unhappy...just trying to help you cut off that corner so to speak.

Good luck

Bock

Tunercat has an OBDII tuner system that works real well. Top speeds are at least 140+ on the straight at MMP. If you do some cam and headwork on the LT1 and get a PCMforless Computer and tune it with a tunercat tuner you will have no problems. I was getting 340 rwhp and 350 tq with my LT1 w/ cam and heads. Change to a 383 and you will exceed these numbers by far.

My nearly stock, LS1 Vert Z28 did 172 mph w the top down, in Nevada ORR a few years ago

Don't know if it's the same limiter (I'm assuming so), but my 95 Camaro with the 3.4L engine had a limiter of exactly 113mph. I know, because that's what the ticket said.

Yes, I was a dumb kid.

Ummmmm, what was your tech speed?

I haven't messed with my computer on my formula and out at V.I.R, I went 120+ didn't really want to look at the speed. Unless the previous owner messed with the computer. I don't know.

Digging up another old thread....

I'm lucky enough to have the 117MPH limiter on my ECU.

What can I do to remove it and stay legal in CMCx??

Will a dealer reprogram it out?

Thanks.

I think to stay legal, you'd have to have a factory tune from a car with VR rated tires. Someone will correct me if I'm wrong. I'm guessing you should take the whole tune and not just remove it from yours (unless they are all identical otherwise...seems like that could be a grey area with regard to the tune).

Good luck with the dealer.

In a pinch, try unplugging the VSS connector on the trans. Without ABS and VSS it won't know what speed the car is going. You'll get a SES light and code, so scan it periodically to see if any others codes are set.

Will diconnecting the VSS hurt/foul up anything else?

If the car is still registered it's probably a violation of state and/or federal law, since the ODO will no longer be ticking.

Speedo won't work.

As I recall in my 1994 OBD1 car, it would light up the SES light only after the car moved. I still had ABS, and the PCM gets speed info also from ABS. Without ABS and VSS the PCM can't know the car is moving.

It will affect the operation of the idle follower function, which may affect low speed driveability.

I don't think it will affect track use at all except removing the 110mph limiter, but YMMV.

I sent mine to PCMforLess.com. Inexpensive and fast. Around $175.

Thanks for the info Alan.

I'm trying to stay legal in CMC and that requires no changes to the ECU. I asked for an exemption though.