Discussion
instead of going on the chatsworth drive out today, I have been around to Joolz new unit in Chesterfield to have the map checked out on the sag.
so the status of the car is decatted, modded back box, extra front air intake, and a pair of GT camshafts giving an extra 40thou of lift.
the last time I had the car on joo`s dyno was at raceprooved this time last year, and it was putting out 355bhp, the only mods done since are the cams and air intake.
the fueling was running quite lean, so Joolz had his work cut out, after 6 hours or so we had to call it a day, with the car was putting out 377bhp, but at 6250rpm it was suddenly running lean again, after several attempts to richen up in this high rpm/throttle site area no more was being achieved, feeling that we have reached the max cycle on the injectors, if the fueling carried on without leaning out then a good 380+bhp should be achieved.
so next step is check out the fuel regulator, injectors, and then a trip back up to Joolz for setting up again, so fingers crossed a very good return on the cams.
I have a photo of the graph, but cant put it up until I get home sunday night.
if anyone has info on the duty cycle of the sag or tuscan s spec injectors please let me know.
and if anyone needs mapping work then Joo is the man, his new business is called Kits and Classics.
so the status of the car is decatted, modded back box, extra front air intake, and a pair of GT camshafts giving an extra 40thou of lift.
the last time I had the car on joo`s dyno was at raceprooved this time last year, and it was putting out 355bhp, the only mods done since are the cams and air intake.
the fueling was running quite lean, so Joolz had his work cut out, after 6 hours or so we had to call it a day, with the car was putting out 377bhp, but at 6250rpm it was suddenly running lean again, after several attempts to richen up in this high rpm/throttle site area no more was being achieved, feeling that we have reached the max cycle on the injectors, if the fueling carried on without leaning out then a good 380+bhp should be achieved.
so next step is check out the fuel regulator, injectors, and then a trip back up to Joolz for setting up again, so fingers crossed a very good return on the cams.
I have a photo of the graph, but cant put it up until I get home sunday night.
if anyone has info on the duty cycle of the sag or tuscan s spec injectors please let me know.
and if anyone needs mapping work then Joo is the man, his new business is called Kits and Classics.
Hi Clive,
As discussed - I have the same problem - injectors can't keep up past 6250rpm... full remap at Power with decat pipes, modified back box, putting out 365bhp (Power say wheels but it's similar figure to SRR which says fly ???!!!)
Looks like your cams are making an extra 10bhp at the moment.. be interesting to see what we both get when we have bigger injectors and another remap...
Let me know when you next going up to get it sorted........ You can follow me up next time if you like
As discussed - I have the same problem - injectors can't keep up past 6250rpm... full remap at Power with decat pipes, modified back box, putting out 365bhp (Power say wheels but it's similar figure to SRR which says fly ???!!!)
Looks like your cams are making an extra 10bhp at the moment.. be interesting to see what we both get when we have bigger injectors and another remap...
Let me know when you next going up to get it sorted........ You can follow me up next time if you like

Hi Clive, if helpful I used higher-rated injectors on my 4.2 S6, sourced by Mark Adams for me, slightly smaller (to give finer spray) than Dom usually installs and have been fine for 20k miles inc. plenty of track use up to occasional 7250rpm - as Joolz knows when he kindly helped in testing at mallory. Fine up to '377bhp at wheels' and more importantly for injectors 330lbft, when JR mapped it at TVRPower.
They are Bosch Type III 'light grey range' 275cc/min, ref 0 280 156 095.
Say hi to Joolz for me
They are Bosch Type III 'light grey range' 275cc/min, ref 0 280 156 095.
Say hi to Joolz for me

Edited by tail slide on Monday 30th April 20:38
Can't help with the technical information, but discovered my Tuscan was running lean top end last RR session. Having spoke to Jason at Str8six he advised larger flow(?) injectors, I believe Bosch Green Top were mentioned? Anyway she's off there later this month for a set, re-chip, and few other bits.
Hopefully I'll get back to SRR soon after for a comparison.
Hopefully I'll get back to SRR soon after for a comparison.
well I`ve been busy getting the car ready to go back and let Joolz work his mapping magic, so I thought I`d give an update on progress so far.
since my lasy visit and chatting to Joo about airboxes, and also Joo now having undertaken his tests on the T350 race car, I have made a stainless steel airbox with shorter inlet lengths, its not quite 100% finished as I am waiting on some new stainless catches to clamp the new airbox top to the existing bottom half, but with a fitting session this evening its looking good I just need to fit some jubilee clips on the short silicon hoses to connect the inlet tubes to the throttle bodies and once the catches are on then that part is ready.



I have also bought another set of throttle bodies and fuel rail, the rail will just be treated to a polishing session, but the throttle bodies have been ported out to allow smooth flow from the inlet pipes into the TB and then bead blasted on the outside to give them a fresh new look.
The throttle spindles have been removed and thinned down on one side, so hopfully every little bit will count and show an improvement once mapped when back on Jool`s dyno.
the standard airbox can easily be fitted back on for a back to back test to show any improvement/differences between the two.


Along with a few other mods shown here, http://www.pistonheads.com/gassing/topic.asp?h=0&a...
it would be nice to get near the 400bhp mark on a 4lt engine, funny thing is I`m only looking to achieve what TVR said the car would do in the first place
somehow all this reminds me of playing with my old griff
since my lasy visit and chatting to Joo about airboxes, and also Joo now having undertaken his tests on the T350 race car, I have made a stainless steel airbox with shorter inlet lengths, its not quite 100% finished as I am waiting on some new stainless catches to clamp the new airbox top to the existing bottom half, but with a fitting session this evening its looking good I just need to fit some jubilee clips on the short silicon hoses to connect the inlet tubes to the throttle bodies and once the catches are on then that part is ready.



I have also bought another set of throttle bodies and fuel rail, the rail will just be treated to a polishing session, but the throttle bodies have been ported out to allow smooth flow from the inlet pipes into the TB and then bead blasted on the outside to give them a fresh new look.
The throttle spindles have been removed and thinned down on one side, so hopfully every little bit will count and show an improvement once mapped when back on Jool`s dyno.
the standard airbox can easily be fitted back on for a back to back test to show any improvement/differences between the two.


Along with a few other mods shown here, http://www.pistonheads.com/gassing/topic.asp?h=0&a...
it would be nice to get near the 400bhp mark on a 4lt engine, funny thing is I`m only looking to achieve what TVR said the car would do in the first place

somehow all this reminds me of playing with my old griff


Fantastic bit of engineering Clive !
Can't wait for the test results....
Loving those throttle bodies...
Out of interest, is there any reason why car manufacturers don't make airboxes out of metal normally ?? That shiney SS one looks awesome, so much better than the poor quality plastic standard one, but will there be heat issues at all with it being metal??
bottom of airbox is standard, air drawn from underneath and also from front of car, see link to other thread for details on my previous post.
manufacturers use plastic as its cheap for mass production and light in weight, I`ve weighed the top of the standard airbox and it is 1.8kg, my stainless version is a bit heavier as you`d expect at 2.9kg.
the box is made from1mm thick sheet, and tubes are 57mm o/d x 1.2mm wall thickness.
manufacturers use plastic as its cheap for mass production and light in weight, I`ve weighed the top of the standard airbox and it is 1.8kg, my stainless version is a bit heavier as you`d expect at 2.9kg.
the box is made from1mm thick sheet, and tubes are 57mm o/d x 1.2mm wall thickness.
now the kitchen is finished (and I`m allowed back in the garage)
I`ve found time to fit the throttle bodies, along with a set of thermal insulators from Tvr Power, new injectors are in, along with a polished up fuel rail, all ready for final fitment of airbox, take it for a good run and then balance the throttles etc and ready to go.







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