Tuning my V8S 4 litre
Discussion
Lol, well had the car on the rollers at Nobles today .. this is the events so far..
Bought my S a few years ago from a friend of mine, i bought it because i knew the car, knew the owner and knew it had had a lot of money spent at the right times. it was a nice car
Over the years it's been modified and generally used as a mobile test bench for a few things I've wanted to try over the time. It's now done 103000 miles, i've done probably 30000 of those since i bought it.
It's never been a ball of fire .. it already had a Tornado chip in it and was very smooth and pretty quick but never startling .. it was high miles and i accepted that.
As time went on I added stuff like AVOs and eventually had some Nitrons built specifically for it, put decent rubber on track day wheels, increased the front brakes to griff 500 size and went giant-killing around the twistier tracks of the country.
The power of the car was measured about a year or more ago with a carbon plenum on at 170bhp, with nothing drastically worng with it, I thought that was all the car was capable of .. then a few months ago I took the carbon off and blended the trumpet base .. the car was now definately running too weak though .. pumping the throttle during accelration brought an increase in the acceleration rate which died off if you kept your foot still .. the accel enrichment was making the mixture better for power. Just after doing the blended base it did 178bhp.
And so on to today at Nobles .. I'd told Darren that I didn't expect great things of it, but wanted a benchmark graph for when I do the megasquirt mapping on it at some point in the near future .. the car had felt very slow at Snetterton track day (it had done at all the track days over the last few months but snetterton showed it to it's fullest with that looooong straight) so i knew that the car was losing power and put it down to the high miles and maybe a cam wear issue as it has never had a camshaft change in all it's years and miles. I thought it was maybe down to the 170bhp ish it had before..
.. so this is where it gets interesting .. the car is just as slow now as it was at snetterton and all the track days before it over the summer .. the car was great through the corners .. more than enough to offset the poor HP it has .. just like our tasmin it proves HP is nothing compared to grip to get you a fast lap time ..
Darren at nobles came through to tell me the first bit of news .. the car was certainly running weak and he didn't know how it had kept going!! .. lamda 1.15 (about 25% weaker than you would want under load) .. and it made 130bhp when he aborted the run.!!! It had peaked at 4200rpm, that was all it had got!
My heart sank, I had visions of blocked cats and worn rings / bores .. then came some very good news
Darren had clamped off the fuel return line to get the fuelling up and the car made 198bhp at 5900 rpm!!
For a 103000 mile 4 litre that gets a regular thrashing on track and has never had an easy life I think that's tremendous. But what's even better is that the car was still fast on the snetterton track day even with 130bhp so it's going to be great fun now!
I don't know at what point the pressure regulator has decided to finally call it a day but it's been feeling this slow for ages and ages so all the recent track days have been done with 130bhp or at least very close to it .. bugger!
I'll try and get my scanner working so I can upload the before and after graphs.
The most interesting thing to me though is that it's 28bhp up on the previous best figure when it had no apprent fuelling issues .. everyone's been saying that an hour with the grinder and the short induction length won't get me good power .. this kind of disproves that theory .. torque is still 190lb.ft at 4500 rpm but holds it right to teh very top, it's still got 175lbs near enough at 6k revs and no nasty dips in the rest of it.
I'm a happy bunny .. now to fit the megasquirt
couldn't get scanner working so here's a digicam pic of it, sorry about tehgreyness / bad quality etc
>> Edited by trackcar on Wednesday 12th October 18:22
Bought my S a few years ago from a friend of mine, i bought it because i knew the car, knew the owner and knew it had had a lot of money spent at the right times. it was a nice car
Over the years it's been modified and generally used as a mobile test bench for a few things I've wanted to try over the time. It's now done 103000 miles, i've done probably 30000 of those since i bought it.
It's never been a ball of fire .. it already had a Tornado chip in it and was very smooth and pretty quick but never startling .. it was high miles and i accepted that.
As time went on I added stuff like AVOs and eventually had some Nitrons built specifically for it, put decent rubber on track day wheels, increased the front brakes to griff 500 size and went giant-killing around the twistier tracks of the country.
The power of the car was measured about a year or more ago with a carbon plenum on at 170bhp, with nothing drastically worng with it, I thought that was all the car was capable of .. then a few months ago I took the carbon off and blended the trumpet base .. the car was now definately running too weak though .. pumping the throttle during accelration brought an increase in the acceleration rate which died off if you kept your foot still .. the accel enrichment was making the mixture better for power. Just after doing the blended base it did 178bhp.
And so on to today at Nobles .. I'd told Darren that I didn't expect great things of it, but wanted a benchmark graph for when I do the megasquirt mapping on it at some point in the near future .. the car had felt very slow at Snetterton track day (it had done at all the track days over the last few months but snetterton showed it to it's fullest with that looooong straight) so i knew that the car was losing power and put it down to the high miles and maybe a cam wear issue as it has never had a camshaft change in all it's years and miles. I thought it was maybe down to the 170bhp ish it had before..
.. so this is where it gets interesting .. the car is just as slow now as it was at snetterton and all the track days before it over the summer .. the car was great through the corners .. more than enough to offset the poor HP it has .. just like our tasmin it proves HP is nothing compared to grip to get you a fast lap time ..
Darren at nobles came through to tell me the first bit of news .. the car was certainly running weak and he didn't know how it had kept going!! .. lamda 1.15 (about 25% weaker than you would want under load) .. and it made 130bhp when he aborted the run.!!! It had peaked at 4200rpm, that was all it had got!
My heart sank, I had visions of blocked cats and worn rings / bores .. then came some very good news
Darren had clamped off the fuel return line to get the fuelling up and the car made 198bhp at 5900 rpm!!
For a 103000 mile 4 litre that gets a regular thrashing on track and has never had an easy life I think that's tremendous. But what's even better is that the car was still fast on the snetterton track day even with 130bhp so it's going to be great fun now!
I don't know at what point the pressure regulator has decided to finally call it a day but it's been feeling this slow for ages and ages so all the recent track days have been done with 130bhp or at least very close to it .. bugger!
I'll try and get my scanner working so I can upload the before and after graphs.
The most interesting thing to me though is that it's 28bhp up on the previous best figure when it had no apprent fuelling issues .. everyone's been saying that an hour with the grinder and the short induction length won't get me good power .. this kind of disproves that theory .. torque is still 190lb.ft at 4500 rpm but holds it right to teh very top, it's still got 175lbs near enough at 6k revs and no nasty dips in the rest of it.
I'm a happy bunny .. now to fit the megasquirt
couldn't get scanner working so here's a digicam pic of it, sorry about tehgreyness / bad quality etc
>> Edited by trackcar on Wednesday 12th October 18:22
figures are flywheel corrected Timbo. I don't do wheel figures.
In the past I've usually done track days and changed up at 4k revs .. I've never been interested in revving the engine high and always had plenty of track speed at 4k rev limit to have fun and pass a few supposedly faster cars ..
seems now that I wouldn't have got much better by going higher anyway .. i used to use 5k when really pressing hard and let it run to 6k when in hooligan moods ..
On the 2 mile bruntingthorpe runway the car managed just 132mph shortly after i first got it suggesting it was down on power from the day i bought it..
In the recent spec, changing up at just over 4k revs would have been quickest for me anyway! lol.
In the past I've usually done track days and changed up at 4k revs .. I've never been interested in revving the engine high and always had plenty of track speed at 4k rev limit to have fun and pass a few supposedly faster cars ..
seems now that I wouldn't have got much better by going higher anyway .. i used to use 5k when really pressing hard and let it run to 6k when in hooligan moods ..
On the 2 mile bruntingthorpe runway the car managed just 132mph shortly after i first got it suggesting it was down on power from the day i bought it..
In the recent spec, changing up at just over 4k revs would have been quickest for me anyway! lol.
bridgdav said:
Didn't UKBOB get about 240BHP from his V8S on the Austec rollers after the Mark adams chip...?
Pod's and my V6's made about 175BHP after the Dastek chip upgrade... But my torque figure was at 224 lb ft IIRC...
Mightly impressive with the miles on your though..
Dave
IIRC Dave, UKBobs car did something like 257bhp after the remap, dont know what else had been done to it, but it was around those figures, he will be along soon enough to confirm. Are those figures at the flywheel Jools? My car has done 96K miles and last time on the rollers did 231bhp and 259 lb ft torque at Austec. Before the remap it did 220bhp & 210 lb ft torque at the AMD PH rolling road day. Will see as mine is on the rollers today for a check up.
From what I have been told around 200bhp is quite normal for the 4ltr, any above that have had work. Mine has had work by TVR Power.
Very good gains though, which is all that matters.
Mike
TimW said:
what is the most from a 4litre anyones ever seen.? from any tvr rover v8. 4litre.(no turbo/4.6etc)
The two highest I know of are Harrys which is around 270bhp and Gifdys which is around 265bhp. Harrys spent thousands getting it to that figure and Gifdy had the full TVR Power rebuid, C/F twin plenum, tornado chip etc...
I wouldnt think you could get much more from a 4 ltr than the two above.
IMHO
Mike
I don't know how the Noble RR figures compare with figures from Power Engineering, but in its original form my V8S cat was measured at about 198 bhp at PE. That was about the norm for a good 4.0 on that road; non-cat engines typically put out about 5 bhp more. Although 130 bhp sounds depressingly low, a relatively torquey engine putting out 130 bhp will go a lot better than a smaller engine with a more conventionally shaped power curve peaking at 130 bhp. Having what amounts to a 50% power increase must be very nice indeed though. 
TimW said:
what is the most from a 4litre anyones ever seen.? from any tvr rover v8. 4litre.(no turbo/4.6etc)
My original engine went from 198 to about 235-240 bhp but it took a lot of work to do it - a pretty wild cam, stage III heads, all the intake goodies that ACT did at the time, and fuel mapped by Mark Adams. The result was an engine that pulled well at the top end (hence the peak figures) but was distinctly cammy to drive, and the performance didn't go up as much as you might expect based just on the headline figures. There wasn't a lot more I could have done to it without getting seriously expensive and I have trouble understanding how others manage to get significantly more power and especially *torque* out of similar engines.
These are all Power Engineering figures corrected to flywheel bhp.
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