Black and mean from the Netherlands

[flatline]

Hey there guys,

Was already reading the board for a while now, but never properly introduced myself.

I live in Holland and sincs 2 months a happy owner of a nice 1999 all black Viper GTS.

They previous owner already put some nice mods on the car and are as followed:

Heffner 650 package (only on standard shortblock now)
Headwork
Heavy duty valve springs
Stainless steel valves (2.02 intake and 1.60 exhaust)
Titanium valve retainers
1.7 T&D roller rockers
Alu flywheel
Smooth tubes
Modified airbox with K&N panel filters
70mm TB’s
Magnecore wires
Crower Comp cam (stage 2 int 275/exh 284)


3.55 gears
Venzano seats
Stoptech BBK
Kinesis 18" wheels with Cup tires (semis)
Full B&B exhaust
All emblems removed
White lightcovers (blinking lights)
MGW goodies
Autoform rollbar
VECII
etc etc.

Car is insane to drive coming from a Z3 M Coupe

I def. have some ideas for the near future, but first want to get the car properly mapped. Went on the dyno last weekend and the results are:

RWHP 471,1 @ 5433
RWTQ 542,9 @ 4157


I think that the numbers are a little low for the stuff done to the car, so maybe a good tune will help get the numbers where they need to be, what do you guys think?

I have some more friends with a viper over here, so whenever you guys are going to the Ring or so, let me know and we'll hook up. Also was planning for the next tunnelrun to come along, but unfortunatly can't make it.....

Hope to see some of you guys soon.

Here some pics and vids of my car:

http://www.youtube.com/watch?v=MJ6cnX8fQYc
http://www.youtube.com/watch?v=sLhvn1cZSF0
http://www.youtube.com/watch?v=tVJEYI8WFrA

[GTSDave]

OOOH!!! I like that! Looks lovely!
Very Mean!

Edited to add:
Welcome aboard! Nice to see another owner appearing, and nice to have contact with another country too! There are a few other 'Euro Viper Owners' here too.

Edited by GTSDave on Tuesday 12th October 12:32

[zubair]

looks much nicer without the front no plate very nice car .

[ringram]

What compression are you running?
What total timing?
If AFR is correct then it may be a tad lean for best power. 13:1 might be better. It mostly looks like 14:1 at present.
Usually Viper engines run fairly low compression which doesnt help power.

[flatline]

Thanks guys for the reactions, love england because there are a lot more petrolheads over there and the roads are a lot nicer

@ Ringram
I really don't know what the compression is at current. Is there a way to check this without removing engineparts?

The dyno owner also noticed that the car was a little on the lean side in the upper RPM's and down in the low RPM's

Would have thought that the engine would make between the 575-600 FWHP Maybe a good tune can bring those numbers up a little.

I also get some spare parts with the car, including heads/exhaust etc, but also a diffrent cam. Don't know if its a standard one. He also has bigger fuel injectors laying around for me to pick-up. Would it make any sense to install them before the mapping?

[flatline]

They put a tailpipe sniffer in my exhaust to measure the A/F, but I got a x-pipe in the back, so they weren't able to measure both cil.banks.

I don't know if its possible to swap out 2 O2 sensors for 2 widebands, just for mapping??

[Dr-Bob]

Speak to DC Performance about a SCT remap and loose the VEC2...

Plug and play and easy to do new uploads...

Great looking Viper....

[ringram]

If they are stock injectors they might be maxed out hence why its lean.
Personally if you can retune the stock ECU as per above, then thats a good idea.
Spare Cam is probably the stock one.
SCT would be my choice too. You probably need to know duty cycle on the injectors to know if they are maxed.
Or check out what they are and figure out line pressure and flow rate to see if they are within spec for the power you are making/need.
So a data logger is a good start. Wideband logs against rpm and airflow will also be useful. Especially if you want to tweak the tune.

[ViperPict]

Nice car! Quite a similar level of tune to my car also.

[flatline]

@Ringram

I do have the Ease software on my laptop which I can hook up to the OBD2 connector. Don't know if I'm able to see what the dutycycle is in the software??

The other cam could also be the one originaly used in the 650 package. Previous owner swapped it for a crower cam to get some more umph in the midrange.

@viperpict
What are your mods and power output?

[ViperPict]

flatline said:

@Ringram

I do have the Ease software on my laptop which I can hook up to the OBD2 connector. Don't know if I'm able to see what the dutycycle is in the software??

The other cam could also be the one originaly used in the 650 package. Previous owner swapped it for a crower cam to get some more umph in the midrange.

@viperpict
What are your mods and power output?

Bear in mind that the car's a 1996 RT/10 (i.e., Gen 1.5)

Stage 3 head work by Valaya Racing
Lightened flywheel
1.7 T+D roller rockers
Bellanger headers
Corsa exhaust (cats removed)
Largened throttle bodies
Gen 2 injectors
K+N filters
708 cam (I think!)
Smoothe tubes
SCT map by DC Performance

It had about 520-530bhp prior to the cats coming out. I know removing the cats don't give much more power but one of my previous high-flow ones had collapsed and was probably really restricting exhaust flow. So, after removing them, the car is far more responsive, especially mid-range. Maybe 550bhp now.

[flatline]

thats indeed about the same as my car. Your power output is 550bhp with that you mean the power @ wheels or @ the crank?

Get mixed up sometimes in BHP/RWHP etc etc....

[ringram]

My "little" LS 7.2L only pumps out 625fwhp and 605ftlb with a small 227/243 cam.
Still more to eek out too. So Vipers 8L engines are a bit behind the times in that respect.

Ive heard the Stryker Heads are very good as well as custom ports by Greg Good. My plan is for a Gen4 viper at some point.

[ViperPict]

flatline said:

thats indeed about the same as my car. Your power output is 550bhp with that you mean the power @ wheels or @ the crank?

Get mixed up sometimes in BHP/RWHP etc etc....

That's flywheel. Approximate numbers as the last time I took it to a dyno it was spinning the wheels a bit near the top end. Going to get it dyno'd again soon on the same dyno but it's recently been recalibrated and had the tread on the rollers redone too (hopefully no slip).

But with crappy road tires, a slipping clutch and the dodgy collapsed cat in the exhaust, I still ran a 12.6 quarter with a 119mph terminal earlier this year(rubbish 2.3 60ft too - tires meant no grip off the line).

Edited by ViperPict on Tuesday 12th October 22:05

[viperboy]

Nice car, could do with some silver stripes

[flatline]

No, maybe want to put dark grey striping on the car, but not sure yet

First need to get the car running like it should...

[GTSDave]

How about some Matt Black Stripes, make it a negative of this...

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

[flatline]

Was looking into my Ease software which I run during the dynotest.

In the playback I see that the Absolute Throttle position is only 80.4% at the most. I geuss that's a little to low?

Maybe you guys can see more info thats important?

[ringram]

Yeah what was atmos pressure?
84kpa is about 15kpa off max. Some throttles only read 80% max anyway. It depends. Is it DBW or Cable? Check you are getting full throttle.
With that amount of vaccum you are down a good amount of power.
Some things to look into anyway.

[flatline]

its cable operated.

When in midrange on full throttle the vacuum sometimes goes to 8,4 kPaA

Does numbers doesn't make any sense to me, because I dont knwo what it says and what it should be.....