S2 Water Pump Underdrive
#1
S2 Water Pump Underdrive
Any interest in having a run of water pump under drive pulleys made? I've been in chats with Dennis @ HGB Motorsports to get one made for my S2 to test and see if I can alleviate some high temperature concerns on track/autocross while not under driving the A/C & alternator.
If we can get a decent group of folks interested the cost is pretty reasonable![](https://static.xx.fbcdn.net/images/emoji.php/v9/ta5/1.5/16/1f642.png)
Dennis from HGB quoted the following (subject to change pending design changes from where we're at):
"Oh yeah. Basically cost breaks down like this:
1 = $325
2 = 175
3 = 160
5= 150
So anyone else want to get in on the Ken development and my cad/manufacturing it would help out pricing substantially. I would get one myself but I don't have an S2 car.
Lead time is about 3-4 weeks."
Dennis also had this to say for those wondering about Series 1 cars, "S1 could be done as well for basically the same(ish) costing break down. The bolt pattern is different and a diameter adjustment "
The reason I'm going down this path was ~220F coolant temps in a lap or two of VIR, but more concerning was 217F coolant temps in a single 60 second autocross run from my radiator fan set point of 194F on the starting line. I'd really like to under drive the water pump and keep temps under control to not risk the engine.
So far it sounds like we have at least one other Series 2 owner interested.
If we can get a decent group of folks interested the cost is pretty reasonable
![](https://static.xx.fbcdn.net/images/emoji.php/v9/ta5/1.5/16/1f642.png)
Dennis from HGB quoted the following (subject to change pending design changes from where we're at):
"Oh yeah. Basically cost breaks down like this:
1 = $325
2 = 175
3 = 160
5= 150
So anyone else want to get in on the Ken development and my cad/manufacturing it would help out pricing substantially. I would get one myself but I don't have an S2 car.
Lead time is about 3-4 weeks."
Dennis also had this to say for those wondering about Series 1 cars, "S1 could be done as well for basically the same(ish) costing break down. The bolt pattern is different and a diameter adjustment "
The reason I'm going down this path was ~220F coolant temps in a lap or two of VIR, but more concerning was 217F coolant temps in a single 60 second autocross run from my radiator fan set point of 194F on the starting line. I'd really like to under drive the water pump and keep temps under control to not risk the engine.
So far it sounds like we have at least one other Series 2 owner interested.
#3
Registered
Any interest in having a run of water pump under drive pulleys made? I've been in chats with Dennis @ HGB Motorsports to get one made for my S2 to test and see if I can alleviate some high temperature concerns on track/autocross while not under driving the A/C & alternator.
If we can get a decent group of folks interested the cost is pretty reasonable![](https://static.xx.fbcdn.net/images/emoji.php/v9/ta5/1.5/16/1f642.png)
Dennis from HGB quoted the following (subject to change pending design changes from where we're at):
"Oh yeah. Basically cost breaks down like this:
1 = $325
2 = 175
3 = 160
5= 150
So anyone else want to get in on the Ken development and my cad/manufacturing it would help out pricing substantially. I would get one myself but I don't have an S2 car.
Lead time is about 3-4 weeks."
Dennis also had this to say for those wondering about Series 1 cars, "S1 could be done as well for basically the same(ish) costing break down. The bolt pattern is different and a diameter adjustment "
The reason I'm going down this path was ~220F coolant temps in a lap or two of VIR, but more concerning was 217F coolant temps in a single 60 second autocross run from my radiator fan set point of 194F on the starting line. I'd really like to under drive the water pump and keep temps under control to not risk the engine.
So far it sounds like we have at least one other Series 2 owner interested.
If we can get a decent group of folks interested the cost is pretty reasonable
![](https://static.xx.fbcdn.net/images/emoji.php/v9/ta5/1.5/16/1f642.png)
Dennis from HGB quoted the following (subject to change pending design changes from where we're at):
"Oh yeah. Basically cost breaks down like this:
1 = $325
2 = 175
3 = 160
5= 150
So anyone else want to get in on the Ken development and my cad/manufacturing it would help out pricing substantially. I would get one myself but I don't have an S2 car.
Lead time is about 3-4 weeks."
Dennis also had this to say for those wondering about Series 1 cars, "S1 could be done as well for basically the same(ish) costing break down. The bolt pattern is different and a diameter adjustment "
The reason I'm going down this path was ~220F coolant temps in a lap or two of VIR, but more concerning was 217F coolant temps in a single 60 second autocross run from my radiator fan set point of 194F on the starting line. I'd really like to under drive the water pump and keep temps under control to not risk the engine.
So far it sounds like we have at least one other Series 2 owner interested.
#5
Not 100% sure yet, but we're testing on my car now.
It would definitely be interesting to duplicate the Speedsource pulleys, especially since they're S1 & S2 compatible.
It would definitely be interesting to duplicate the Speedsource pulleys, especially since they're S1 & S2 compatible.
#6
Most people just purchase an entire poly kit. So it would be silly of me not to offer all the bushing components in superior Delrin. It really makes the rear end more consistent by eliminating a lot of the rotational spring force the rubber bushings put in the system. I desgned and built these before sphericals were allowed in SP.
I'm building the pulley based on docwalts request. I have no skin in the game other than doing the CAD work and having them made. The potential customer did all the testing and has solid logic for this pulley.
The following users liked this post:
DocWalt (04-29-2021)
#7
S2 water pump is already under driven compared to the S1. I found out pretty recently the s2 pump bolt pattern doesn't match the s1 though.
I'd be interested in a solution to underdrive the s1 water pump & alternator if it is reliable and the cost is reasonable. Doesn't need to support AC.
I'd be interested in a solution to underdrive the s1 water pump & alternator if it is reliable and the cost is reasonable. Doesn't need to support AC.
Last edited by blu3dragon; 05-11-2021 at 12:17 PM.
#8
S2 water pump is already under driven compared to the S1. I found out pretty recently the s2 pump bolt pattern doesn't match the s1 though.
I'd be interested in a solution to underdrive the s1 water pump & alternator if it is reliable and the cost is reasonable. Doesn't need to support AC.
I'd be interested in a solution to underdrive the s1 water pump & alternator if it is reliable and the cost is reasonable. Doesn't need to support AC.
#10
![](https://i.postimg.cc/MGDYYdR2/image.png)
Got the underdrive pulley installed easily, just bolted on like stock. I've done some logging too, good temps while cruising around (180F stable with AC on, as usual) and temps so far are better at autocross. They still recover super quickly too and I'm not seeing as wild high temps. I used to see 217F at the end of autocross runs, I've done one event and I'm only seeing 205F as a peak on course even with a lot more rev limiter action at 9800 RPM. No more autocross events planned this year for me, sadly. Might get to do a track day or autocross, unsure though!
Big thanks to Dennis at HGB Motorsports for the pulley and hand delivery at nats!
#11
Probably going to take into the mid-summer next year to see how effective this really is. At least that's my initial thoughts after my own giant water pump pulley install a little over a month ago, and a few autocrosses. Though, like you, my results so far also seem extremely promising.
Damn 9800rpm! Just thinking of the speed that translates to in second gear makes it clear I am too slow.
Damn 9800rpm! Just thinking of the speed that translates to in second gear makes it clear I am too slow.
#12
Probably going to take into the mid-summer next year to see how effective this really is. At least that's my initial thoughts after my own giant water pump pulley install a little over a month ago, and a few autocrosses. Though, like you, my results so far also seem extremely promising.
Damn 9800rpm! Just thinking of the speed that translates to in second gear makes it clear I am too slow.
Damn 9800rpm! Just thinking of the speed that translates to in second gear makes it clear I am too slow.
Different course, no way was I hitting limiter at the Ripken event, haha. I did the pulley install after Ripken. I had to disconnect the battery to swap the trans so I just went ahead and installed the HGB pulley.
Thread
Thread Starter
Forum
Replies
Last Post