Porsche Enthusiasts Club Forum :: View topic - Newbie with a 944t Hi, and exhaust question

Hi

I'm a long standing porsche fan, have owned every model that contains water other than a 997, I did wander off into prancing donkey territory for a while though.

I've recently got hold of an 86 944 turbo that had begun its journey to a trackday car. To say it needed some fettling is an understatement but its getting there now. It's pretty raw, full strip out, race suspension, brakes, plexiglass and cage etc. We havent done anything to the engine yet as are concentrating on braking and handling set up, once these are done it may be time to play with the oily bits!

We did a test day last week and began to tune the suspension, think we are sitting a bit low at the rear so a bit more preload required.

Even though it goes really well, the exhaust is standard and you really cant hear it over all the bits falling off and rattling!

Eventually we will update the full system but I was wondering what happened if you replaced the rear box with a straight pipe? It's track use only so just needs to be sub 100dB. I dont think there is any performance advantage to a back box only system and from what i've seen the standard exhaust is pretty well sorted.

Anyone got any hints as how to make it sound like a race car on a b&q budget, temporarily?

Author:	c928jon [ Sat Jun 19, 2010 7:27 am ]
Post subject:	Newbie with a 944t Hi, and exhaust question
Hi I'm a long standing porsche fan, have owned every model that contains water other than a 997, I did wander off into prancing donkey territory for a while though. I've recently got hold of an 86 944 turbo that had begun its journey to a trackday car. To say it needed some fettling is an understatement but its getting there now. It's pretty raw, full strip out, race suspension, brakes, plexiglass and cage etc. We havent done anything to the engine yet as are concentrating on braking and handling set up, once these are done it may be time to play with the oily bits! We did a test day last week and began to tune the suspension, think we are sitting a bit low at the rear so a bit more preload required. Even though it goes really well, the exhaust is standard and you really cant hear it over all the bits falling off and rattling! Eventually we will update the full system but I was wondering what happened if you replaced the rear box with a straight pipe? It's track use only so just needs to be sub 100dB. I dont think there is any performance advantage to a back box only system and from what i've seen the standard exhaust is pretty well sorted. Anyone got any hints as how to make it sound like a race car on a b&q budget, temporarily?

Author:	PaulSmith [ Sat Jun 19, 2010 9:24 am ]
Post subject:	Re: Newbie with a 944t Hi, and exhaust question
If the system is still 100% standard then the first thing to do is cut out the front box and replace it with straight pipe. This clears the most restriction and will allow the boost to build a little quicker. It makes the note a little more rorty but not much louder. Mine static tests at only 87db from 1 metre. Removing the rear box tends to make it sound like an old Cortina with a holed exhaust

Author:	c928jon [ Sat Jun 19, 2010 11:13 am ]
Post subject:	Re: Newbie with a 944t Hi, and exhaust question
Thanks Paul I'm 99% sure it's still original, there is a centre box, roughly 250mm dia by 600mm long, with the wastegate outlet pipe running alongside and joining after the box. The pipes look to be about 2.75 to 3 inch. If we remove the centre box, and put a dansk or similar back box, i assume we get near a race car note? I know you can get full systems ect, but don't think there is any advantage until you take the plunge and start changing everything wastegate back. We were looking at the Lindsey racing stage 1 kit, chips boost enhancer shims and fpr? You sound like a man who may know if this is worth it?

Author:	PaulSmith [ Sat Jun 19, 2010 7:31 pm ]
Post subject:	Re: Newbie with a 944t Hi, and exhaust question
c928jon wrote: Thanks Paul If we remove the centre box, and put a dansk or similar back box, i assume we get near a race car note? That's the exact same setup I currently have on mine. You can hear it at full throttle on this clip after the car goes past the camera (ignore the turbo whistle beforehand) http://www.youtube.com/watch?v=vBJSzkWtn-c Larger bore exhausts like a 3" or 4" will give benefits once you start getting north of 300bhp Best bang for your buck is the Level 1 kit from Promax or Stage 2 from JMG at just over £300 each http://www.jmgarage.com/modify/modify-944.htm http://www.promaxmotorsport.co.uk/Produ ... turbo.aspx They both have similar components as the Lindsey offereing but give you the support of a British based company

Author:	c928jon [ Sat Jun 19, 2010 8:43 pm ]
Post subject:	Re: Newbie with a 944t Hi, and exhaust question
Thanks for the Youtube link, couldn't help but look at some of the others too, your car is very cool! I don't think anything similar would be achievable on our b&q budget. But at least we can get the exhaust sorted ..Thanks

Porsche Enthusiasts Club Forum https://forums.tipec.net/

Newbie with a 944t Hi, and exhaust question https://forums.tipec.net/viewtopic.php?f=25&t=8807	Page 1 of 1

Author:	tr7v8 [ Sun Jun 20, 2010 7:03 pm ]
Post subject:	Re: Newbie with a 944t Hi, and exhaust question
Hi & welcome Seems like the Boosty boys have already helped you out!

Author:	promax [ Sun Jun 20, 2010 7:46 pm ]
Post subject:	Re: Newbie with a 944t Hi, and exhaust question
c928jon wrote: Hi I'm a long standing porsche fan, have owned every model that contains water other than a 997, I did wander off into prancing donkey territory for a while though. I've recently got hold of an 86 944 turbo that had begun its journey to a trackday car. To say it needed some fettling is an understatement but its getting there now. It's pretty raw, full strip out, race suspension, brakes, plexiglass and cage etc. We havent done anything to the engine yet as are concentrating on braking and handling set up, once these are done it may be time to play with the oily bits! We did a test day last week and began to tune the suspension, think we are sitting a bit low at the rear so a bit more preload required. Even though it goes really well, the exhaust is standard and you really cant hear it over all the bits falling off and rattling! Eventually we will update the full system but I was wondering what happened if you replaced the rear box with a straight pipe? It's track use only so just needs to be sub 100dB. I dont think there is any performance advantage to a back box only system and from what i've seen the standard exhaust is pretty well sorted. Anyone got any hints as how to make it sound like a race car on a b&q budget, temporarily? Removing the centre silencer is recommended. If you remove the back box as well, the car will be very noisy (well in excess of 100db at 1 meter, 4000 rpm). My race car was used with a rear straight through silencer (not a straight through pipe). You can modify the standard rear silencer to achieve what I did. If you want to achieve improved performance at low cost, you need revised software for your DME/KLR ECU combination, a 3.0 bar Fuel Pressure Regulator, Wastegate Shims and a Boost Controller (or Enhancer). With an ’86 car, you should be able to achieve 260bhp (if your car currently makes 220bhp). Paul's suggestions will work well. The 944 Turbo can be reliably tuned beyond 400bhp using the standard 2.5 block, hence there is a lot of flexibility with upgrades, but the suggested modifications should get you a useful and measurable increase in power and torque. Regards, Andrew

Author:	starboard147 [ Sun Jun 20, 2010 9:22 pm ]
Post subject:	Re: Newbie with a 944t Hi, and exhaust question
So are straight pipe centre sections available off the shelf or is it a case of getting an exhaust shop to make one up/modify stock ??

Author:	promax [ Mon Jun 21, 2010 6:50 am ]
Post subject:	Re: Newbie with a 944t Hi, and exhaust question
Check with Andy E at the office, I am not sure if there is a part directly available. Section for my race car was made up from a discarded exhaust (same diameter pipe). Regards, Andrew

Author:	poprock [ Mon Jun 21, 2010 9:33 am ]
Post subject:	Re: Newbie with a 944t Hi, and exhaust question
Slightly off-topic here, but Andrew’s mention of wastegate shims just reminded me … I have a Turbosmart adjustable wastegate—take it off and swap the springs around to adjust opening pressure. Not having any ramps/lifts at home I took it to a local Porsche specialist and asked them to swap the springs over for me a year or two ago. When I went to collect the car he handed me my wastegate shims and said “we found these inside the wastegate and didn’t know what they were for, so we took them out.” Let’s just say I’m not letting them near my car again!

Author:	c928jon [ Mon Jun 21, 2010 1:09 pm ]
Post subject:	Re: Newbie with a 944t Hi, and exhaust question
Right, grinder and welder and some bits of pipe, my style of tuning! Anyone know, off the top of their head, the diameter of the entry/exit pipe to the centre silencer? I'm not anywhere near the car at the mo and want to order some pipe that will slip over the existing (butt welds aren't my speciality a good cm overlap full of lovelly mig juice is my style) Promax...I assume your kit is the lindsay one? It was your phase 1 I have been looking at...Just checking, do you offer any tipec discount or similar..sorry for being cheeky

Author:	promax [ Mon Jun 21, 2010 3:25 pm ]
Post subject:	Re: Newbie with a 944t Hi, and exhaust question
c928jon wrote: Promax...I assume your kit is the lindsay one? It was your phase 1 I have been looking at...Just checking, do you offer any tipec discount or similar..sorry for being cheeky Hi, We were using the Lindsay Boost Enhancer in our Level 1 kits. However, after finding a new manufacturer of Boost Controllers, we should now be able to supply the kits (as previous) with the correct Boost Controller (that increases peak boost - which the Boost Enhancer does not). Our chips are created in house (as with all ProMAX chips), wastegate shims are Lindsey and the FPR is from Bosch. For discounts, you would need to contact the office - 01296 714856. Special promotions do periodically occur which you would then redeem via the website (when purchasing the item the discount applies too). Let me know if I can be of any further assistance. Regards, Andrew

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