HP Gains

[mntngts99]

This last season I meet a gentlemen that has his own Custom Flow Tuning Facility. He said that the throttle bodies could be rework for a minimum gain of 50 HP and 60 ft-lbs torque. I found a used set of 58mm from a 1996, are they the same as my 1999? Has any one done this mod,what gains were achieved?
Thanks for your time.

 

[Mike Adams]

5 hp to 10 hp max

 

[RedGTS]

What Mike said. And you may actually lose power and particularly torque with a stock or mildly modified car. The gentleman knows nothing about Vipers.

 

[mntngts99]

Ok, so lets say I buy a used set of throttle bodies and have them done. Then do a before and after dyno. If the HP and TQ #'s are there, then it would be worth the few hundred bucks,if not. Oh well. Save my money or give it a try?

 

[WCKDVPR]

mntngts99,

I think enough people have tried this (on a dyno) and found the 58mm TBs work best until you have around 500 RWHP. Then a jump to 65mm makes more power. With big HP numbers, the 70mm TBs can work effectively.

You need to keep up the velocity through the TBs, so on a fairly stock motor the 58's actually make the most power.

Same goes with flow numbers on heads if you ever go that route. There is a lot more to making power than who's heads have the most CFM at a specific lift. Bigger is not always better.

If you still really want to try it, I would expect someone out there would borrow you a set of larger ones to go test them, as long as you post the dyno sheets

Have fun, regards,

 

[mntngts99]

I guess the one mistake I've made was thinking the 58mm were stock. What I am wanting to do is on a stock set of TB. What size is OEM. The last time I looked for a set I came up empty handed.

 

[Marv S]

http://www.viperclub.org/faq/powerfaq.html#tbodies

 

[mntngts99]

After re-working the stock T&B's I found about 20+ RWHP and 30+ RWTQ between 3600 and 5200 RPM's. The total H/P gains were not that impressive, but there was useable gains throughout the mid-range as well as better throttle response.

 

[joe117]

I'm not going to argue against what you say but I think you are the first one to come up with numbers like that for what you have done.
Can you post the before and after dynos?

 

[jcaspar1]

What did you do to them to rework them?

 

[mntngts99]

Monday I'll try to get the dyno sheet posted.

As far as the work done to them, A leading and trailing edge was beveled on the butterfly's and the inlet leading edge of the throttle body was tapered and reworked for better flow with less air disturbance.The shop that did this for me said, "they just make what's already there, work more efficiently". That's all I know.

 

[Fred(DrivingSchool)Kinder]

CDI did a little engine work and on their engine dyno larger throttle bodies lost one hp.

The restriction is in front and after the throttle body.

A stock motor will not gain hp from larger throttle bodies.

Dyno results can vary.

 

[Tom F&L GoR]

I still can't get the logic to this. If as Fred says, the restriction isn't the throttle body (and I really believe it's the runner size) then a larger throttle body can't help *or* hurt. The only way it can hurt isn't the "slow air speed" since it would have to speed up again in the runner, but the mismatch between air flow and throttle position sensor (I know, at WOT that would not matter.) Not trying to disagree with apparent dyno results, but if someone can explain why, I'd like to hear.

 

[Fred(DrivingSchool)Kinder]

Hi Tom,

Call Dan Cragin or Glen at CDI for the theory. I just remember the evaluation of my stock vs larger TB's. The motor in question had an extrude hone intake, P.P. heads, roller rockers and a little extra intake help from cam work.

 

[mntngts99]

Well I got the image in my gallery but when you click on it , it's way BIG. In the test post area it's way small???
Man I hate computers. I just got the sheet today and when talking to the dyno shop over the phone last week he told me that there was a 20+ and 30+ gain between 3600 and 5200 RPM's, But that was at a given RPM. What controls the viewing size when you post?? how do you change it ??

 

[2002_Viper_GTS_ACR]

Re: TORQUE Gains

For a 99, you seem to be a bit down on power. Shoot, even with your throttle bodies, your not making more then my cremepuff did stock. I wonder if these TB only help on cars that are deficient in power from the factory ? Please dont take that as an attack. I am saying that, would it be the same gains from a motor that pulled 410hp, 450 tq from the factory ??

I will also point out, that you say HP GAINS as your post, but really your biggest gains are your Torque !! 5HP AND 20TQ. Again, NOT a bad thing, just wonder if similar gains can be expected on other cars.

Jon

 

[kverges]

Re: TORQUE Gains

Oh wow, be careful here! Forget the power issue - if it is not a careful and reputable "re-work" the screws for the throttle plate could come out and severely damage the engine. This anonymous and extraordianry claim would have me inquiring very, very carefully about the parts before I bolted them to my car.

 

[mntngts99]

Re: TORQUE Gains

Well I'm not the best poster as you can see. I've been around for more the two years with only 106 post. the first post on this thread should of had a ? mark on the title. looking at other dyno sheets I felt mine was down on power too. I have had it to our local viper tech two times and he said all is good. The only dyno shop we have here, has dyno sheets on two other vipers and all of our numbers are about the same. Don't know if its the dyno or what. As far as parts falling off,If so, then maybe my next motor will be stronger. Next week in Vegas I should find out how my car runs compared to other vipers.

 

[utahviper]

Re: TORQUE Gains

Well here it is: The power is down a little but nevertheless it has some great gains in the midrange. How much does it cost to get it done? I might be interested. He may be down on power but he can more than drive to make up for the difference. I think he told me low 11's in his car on pilots. That is awesome.

 

[mntngts99]

Re: TORQUE Gains

Todd
It cost $135.00 pulled them off sent them and had them back on in a week. I know that total gains are not big but it does feel better in the mid-range.

 

[joe117]

Re: TORQUE Gains

Why would that kind of mod improve mid range more than top end?

And,
If it's only making about 15hp more while accelerating through 3800rpm at full throttle,
how can it "feel better in the mid range"?

You can feel that?

The only reason I question this so much is that this is the first time I've heard of any gains from this kind of mod.

 

[mntngts99]

Re: TORQUE Gains

I'm almost sorry I even did this, a lot of people said that their would be NO gains but their was some, so I thought I would share. All I know is that I'm not disappointed.

 

[joe117]

Re: TORQUE Gains

Jeez, don't get all upset just because there are questions.

Not disappointed? I guess that means you can feel those extra 15 hp.

And by the way, you started this by saying the guy told you his rework would give "a minimum gain of 50 HP and 60 ft-lbs torque".

Think we all should have said, "that's super, I'll have some"?

We called BS. We were right.

 

[mntngts99]

Re: TORQUE Gains

joe117

That's one thing I like about this board, people say it like it is. As far as being disappointed. I tried something that I was expecting no gains on and got something, however little it might seem to you. Haveing a little more torque and a little more HP is better then going the other way. If having a little more HP and torque is not a good thing,then why does the #1 mod for all stock vipers include K&N filters and Smooth Tubes?

 

[BigCarrot]

Re: TORQUE Gains

[******], I'd do it! I like the dyno sheet!